BritishV8 Forum

Anyone know how large you can go on the valves for these heads without changing the seats?

I've seen valves about .050" larger for both ex and intake. That hardly seems worth the trouble and expense unless the old ones have to be replaced.

Jim

Rimmer bros and the Wedge Shop sell larger valve for the Rover heads. Pretty close to the Buick 300 sizes. Years ago I changed the seats and used Ford 2.3 SOHC 1.74 IN and 1.5 EX valves in a 300 head. Probably could in the Rover also.

That'd be a substantial increase. The intake is about 1.570 and the exhaust is about 1.350. The alloy 300 heads have a little larger intakes and smaller exhausts, around .040 difference in each case I think. There is slightly over 3/16 between the valves so I expect that'd be about the limit.

Just for reference the TA heads have the valves repositioned and can go bigger, up to 1.6 and 2.0 in although we decided a 1.9 made more sense.
Jim

Larger Rover valve sizes in this link:

https://thewedgeshopstore.com/tws-performance-rover-v8-heads-3-5-3-9-4-0-4-6/

Ok TWS. lets see the flow $'s for $2,100 ?

In case anyone is interested, here's a slightly less expensive alternative.  Price is 1550 GBF plus 200 GBF (core).  They are CNC ported and the size of the valves is 1.63" intake and 1.4" exhaust.  I've asked for flow numbers.

https://johnealesroverv8.co.uk/product/stage-2-ported-cylinder-heads/

Eric, Plus shipping back and forth. Wedge Shop (TWS) might be more like their Stage 3 too.

Jim, agreed.

Saw those, not real impressed with the valve sizes. I mean if I'm spending $18 each for valves I'd want to get a little more than that I think. Probably just stick with the originals, they seem to be in good shape.

Jim

Hi,

1,63" intake and 1,40" exhaust valves are typically available and fit factory seats. That´s what I have fitted in my Rover heads.

One thing to consider: I have not had much luck finding uprated springs (read inexpensive) for Rover heads. Sure there are double springs available but all the additional parts + possible machining start adding up costs. Also quality of rockers and rocker shafts is pretty poor. I have a pair of new rockers shafts that have smaller OD than worn factory shafts. These came from a reputable source in UK.  

Jukka

Here is a link to a UK magazine article from mid 90´s when P38 type 4,0 / 4,6 litre engines arrived. It has some useful info about component dimensions

https://drive.google.com/file/d/1uqbLrqPhEsE2csIoIGyt8P5T1rZguPS7/view?usp=sharing

Jukka,

That's a very useful article.  I'm curious about one thing.  The article says the 4.6 heads have a combustion chamber of 28 to 31 cc, while I think I've read somewhere else that they are 22 cc.  Am I missing something?  That would make a big difference in my calculations.

Never, ever heard 22cc, Eric.  More like 28 to 29cc.

There are few odd remarks in that article.

Carl,

Probably need to get my eyes checked.  Thanks for the confirmation--now have to redo my calculations.

"So, in addition to deleting these bolts a new thicker composite head gasket has been introduced, and the deck height has been reduced by a corresponding amount."

Say what?!  In all these years, I have never heard that the deck height was changed.


"...and the production conrods and pistons remained weak."

Do the Rover V8 engines not use a forged connecting rod?  I know that the Buick/Olds 215 does.

Carl,

I did read somewhere else that the later Rover heads used a thicker gasket and that the combustion chamber was accordingly reduced by shaving the head--I *think* that's what the article was trying to say, but it made it sound like it was the block that was reduced, which I don't think was the case.  Still wondering where I saw that 22 cc reference...

Not sure about the Rover rods, though.

Yes, Rover shaved the heads to compensate for the thicker composite head gasket.  I think they are wrong about the deck height.

That would explain the change in chamber volume.
The 340 used cast rods, pretty sure the 300 did too. One of the early mods to the 215 was to use small journal SBC rods which were forged. How certain are you that the 215 rods were forged?

That 22cc number may have been my fault, I had mentioned that as a piston dish volume because I had some notes from an old engine build that contained that figure. But apparently I never actually used it so as far as I know it doesn't apply to any build.

22cc would be a VERY small chamber volume.

Jim

Ha, no worries on the chamber volume--my numbers do work a bit better now, though :)

I have also read that the 215s had forged rods--I think that was from a spec sheet posted on the V8 Buick site.

I'd bet on it, Jim.  ;)

Jukka and all, for better springs, I use "beehives". Light/steel retainer, clears fat rockers better. Cheapest from Comp Cams
  are a decent upgrade. "Pacalloy" is top-end $.    Art.

I agree with Art on the Beehive springs. I used a set for a Ford recommended by Jim N., came with retainers at a good price. On extra thing to pay attention to with beehives: They should if possible be set close to coil bind at full lift I think within 1/16" or so. This is because you don't get the full benefit of their characteristic damping ability otherwise.

Jim

I've not been able to locate a smaller dia retainers for beehive springs that use the 11 degree stock Rover valve grooves / keepers - unless someone else has a solution? ReelSteel used to sell a custom keeper for the more common GM retainers to mate with the Rover Valves, but not available for several years.

As a result, I am planning on using the Comp 712-16 with Comp 980 springs

And as far as the stock 3.9/4.0/4.6 valves (1.568 / 1.356) go vs the 1.63 / 1.40 of the assumed largest size you can get on the stock seat....

The stock valve throat is around 86% of the valve dia, and the seat job is ok, but not great. If you are going to stick with the stock valves, then a performance valve job, using a .050-.060" wide seat, and a back-cut on the valve, would really help. And a blend of the valve job to the throat of course!

That said, if you go for the 1.63", and bore the throat out to a few thou over 1-7/16", it works out to 88.5% of valve area. Just the CSA of the throat is 13% larger, and of course your curtain area is improved with the larger valve. Personally, I also like the larger throat of improving the shortside just a little by giving you just a little more meat.

CR_quick_reference.png

In response to the questions on the Head CC's, this is my spreadsheet I use for Static CR.

I have measured six different "10-bolt" heads at 28.5CC.

I have Comp beehives on Merlin heads as well as Wildcat heads.

But like Dave already mentioned, there are no retainers to suit beehive spring / Rover valve locks. Unless of course Rover valves are changed to others that use GM type 7 (or 10) degree locks.

Dave, thanks.  28.5 cc is what I'll go with for my planning.

Great info Dave!

QuoteI have measured six different "10-bolt" heads at 28.5CC.

>But like Dave already mentioned, there are no retainers to suit beehive spring / Rover valve locks. Unless of >course Rover valves are changed to others that use GM type 7 (or 10) degree locks.

Well that's a complication. Have to look into that. It's the keepers that are the issue I take it?

Jim

And the valves.  The keeper retention method is different from GM.

May be a good reason to go with larger valves.  ;)

Looks to me like the 4.0 heads use a 10 degree keeper. The notch is the full length of the keeper and is straight. So a plain 10 degree retainer should work. I'm working on finding the sources I used for my beehive springs and retainers.

Here's Precision Products, it seems this is where I bought the keepers:

https://www.pppcenter.com/_files/ugd/1e9d5f_5b3943038b564c1abf43228f257eeee8.pdf

Jim

Yeah, no one else has a keeper of the Rover V8 dimensions, so you are stuck with the only thing that'll work with the standard keepers / valves.

I still feel like it should be possible to machine the common 10 degree ones out to 11 degrees to open up all kinds of possibilities.
Just to clarify, the 11-degree is the one-side angle; the included angle is 22 degrees - per this image.

A taper-attachment on a lathe would make fast/easy work of it, as would a 11-degree tapered end mill in a bridgeport.
I'll not be going over 6200rpm for my engine, so do i really need beehive springs? I'm just not sure....
angle.png

Dave, are you saying the Rover used an 11 degree keeper?

I'm not sure if the difference from 10 to 11 degrees would be enough to make a difference. Maybe someone else can answer that. My actual measurement of one of the keepers from these heads gave 10.5 degrees as far as I could tell. We could be picking at nits here.

Jim N: I'm having a little trouble finding records of my spring purchase. Do you recall where those came from? Seems to me they were an aftermarket  supplier for Ford parts, maybe for FE engines.

JIm

Jim, Alex's Parts.

Been doing some checking, and exchanging some emails with Alex. Of interest, the keepers used in the Rover head are very similar to the ones used by Buick. In fact there is only .004" difference in the stem diameter inside the keeper with the groove in the Rover valves  being slightly smaller, a difference that would almost seem close to manufacturing tolerances. Point being that Buick keepers would probably work fine on Rover valves. Chances seem good that this would get us to a 10 degree keeper and matching retainer for a beehive spring. Waiting to hear back from Alex on that.

Jim

With only .004" difference with Buick keepers, perhaps lap/sand needed amount off of the parting/ mirror surfaces. In other words,
   so keeper halves don't "bottom-out' with each other. What is current shop cost to replace seats ? With new seats, I suspect
   Stage I Buick V6 valves should work.
                                                                             Art.

Buick keepers are 11 degrees too but for 3/8" stems instead of 11/32". Rover are Metric I think 8mm? Also no Buick 11 degree Beehive retainers. Maybe you could make a reamer to cut the common 7 degree Beehive retainer to 11?

Rover valve stems are not metric, they are 11/32". AFAIK all Rover keepers are 11 degrees.

I just confirmed Rover valve stems are 11/32" and are the same diameter as Buick 300 valve stems. Also there is a small gap between the ends of the keepers so they will easily accommodate the .004" size difference. With the same angle they should lock up pretty much the same. Alex had nothing in the required spring diameter and installed height which is 1.240 and 1.560".

I looked at 3800 Buick valves springs but they use a 1.8" installed height.
CC has a #26123 spring with an installed height of 1.470", OD is 1.105" and spring rate of 324 and .500" max lift. Used in Ford mod and Coyote. Finding a suitable retainer might be difficult but perhaps not impossible. Still haven't looked at the specialty retainer catalogs.

PAC has #PAC-1231X which has 127#@1.550" and 287#@1.0" That one might do OK. A little on the light side and getting close to coil bind (rated 302#@.950") but that's what's wanted anyway. Maybe a bit light on the open pressure, hard to say. It's another Ford spring.

Maybe we should be looking at the Mod motor springs.

Jim

From Jukka. in 2018:

QuoteThe Rover keepers are 11 degree. Comp Cams have a set of 11 degree retainers for 1.25" spring, part number 712-16.

Buick 75-78 V6 oddfire valves are almost perfect for oversize Rover valves at 1.62" IN and 1.42 EX. Probably a lot cheaper than Rover valves. Maybe the waisted stem on the Rover valve is 8mm. Rover uses a lot shorter spring than the Buick? I used Z28 SBC springs on the 300 heads. 110 lbs closed and 300 lbs at .500 lift. 1.70 I think, installed height. The Wedge shop has performance springs for the Rover heads.

You could do 1.7" on the 300 heads if you cut the seats  a bit deeper. Installed height 1.635 + .030" washer gives 1.665 so it'd only take .035" to do that. Or you could install at 1.665" and get a little higher spring pressure. IDK if it's from the length of the valve or the depth of the seat.

But, absent a real good reason I intend to stick with the stock Rover valves. With 5.7L displacement in the MGB I don't really have to go looking for horsepower. And this is a spare engine. I will be able to swap on the TA heads if it means that much.

Jim

I used Ford 2.3 SOHC valves which are a little longer.

Any idea what the angle and diameter is for the 3800s that used the beehive springs? Even though they had a taller installed height, if the rest is usable a shorter spring might be found...

Jim

8mm and 7 degrees.

https://www.ebay.com/itm/283207320688?fits=Make%3ABuick&epid=188809319&hash=item41f078c470:g:ykwAAOSwe0Zchl6B&amdata=enc%3AAQAHAAAAsKz3K6l74RE8ZeBPK%2FIqlrORueGYlYJexMBU5wnmEfKoVikIxLBzl4UWc2EsJewC7vf263r6ZcFFU5ej1GI9PLZm6T9zgsItvE12iKnI5VPt%2Fpl65uPsxNvoC5L1PzVqZ2Px25ce7DwNtBueznhFpZ8cunEduTPT1IiZA7F8lmKrqVLBYUC%2FgJgIRvjLYFW5nj5V7DgTEjeUJiFJIV3h5qqia4taRUugS8dGvGeE1d24%7Ctkp%3ABk9SR_yUop-iYQ

77-78 Oddfire V6 valves have 2 keeper slots, 75-76 had same as 300? After 78 Buick V6 went to single 7 degree keeper.
osdfirev6.jpg

OK so none of that really helps does it.
300 valves are 1/16" longer than Rover valves. Otherwise nearly identical except for head size.

I found a source once for a wide variety of retainers, seems like it was a specialty company and that was all they did. I'll try to find that again.

Jim

Jim, That oddfire V6 valve looks like the top groove would use a 7 degree keeper, same length as 300 valve and max size for rover seat. Probably reasonable cost compared to the large Rover valves.

Thanks Jim. I'm going to keep looking for springs and such that can work on the stock valves. I think the 4.6/5.4L Ford springs look promising, not sure about the retainers.

Might have to resort to making a tapered seat cutter for the keepers but I'd rather not. That's kinda a PITA but definitely can be done if I have to.

Jim

Can you cut the diameter of the Buick retainer down? Maybe the step on the under side too? Or ream out the beehive retainer to 11 degrees?

Might use an arbor to hold the retainer and turn it down to fit the beehive. I think that might be the easiest.

Jim

Jim, These Ford 4.2 V6 springs may work for you:
Also 4.6 SOHC V8
https://www.rockauto.com/en/moreinfo.php?pk=8317724&cc=1431298&pt=5792&jsn=770&jsn=770

https://www.rockauto.com/en/moreinfo.php?pk=8317792&cc=1444301&pt=5792&jsn=725

Close but the first one limits cam lift to about .400" and the 2nd one even more. Ideal would be:

coil bind: < 1.000"
Installed Height: 1.560"
closed pressure: 110-125#
rate: > 275# or open pressure > 300#
OD: < 1.240"
ID: > .850"

Such a spring is possible but maybe not available. The easiest thing to change is the OD and ID.

Jim

So far the 4.6L Ford springs seem to be coming the closest.

PAC 1231X is the closest I've found so far:
https://www.racingsprings.com/index.php/valve-spring-11368.html

That one will work with machining of the inner boss from .852 to .720"

Jim

What is the OEM installed valve spring height on the Rover heads, 1.6"?

1.560"

TFS-15411 is another  similar possibility

Jim

That short?  Wondering how everyone is running the 50232 without experiencing coil bind.

BTW what is the difference between the Crower 50232 & 53232 cams?  If the 53232 is for Rover, how is it different?

Carl, Rover cam has a different nose for the retainer plate.

I thought that only applies to the 4.0 & 4.6 engines.

Okay, it's a short nose cam for the crank driven oil pump engines only.

It seems like a very small diameter spring to be developing  a 300# spring rate. Guess it would be light weight though.

Jim

Carl,

Marc at D&D sold me a special set of springs with my Crower 50232 cam. No name or box with them though, just RV-911-16 as a part number on the invoice.

Notes from machine shop that did the work:

"Had to cut the spring seats pockets 0.100 to 0.135" to get 1.665" to 1.675" installed height.
Stock retainers tight to the springs, springs needed chamfer to fit.
Distance to coil bind 0.025" to 0.035".
Seat pressure 105#, open pressure 225#, this is lower than Crower recommendations but recommended by supplier of cam."
"Recommend Howards Cams Spring #98111. Better rate, fitment to retainers and more room to coil bind."

Looking back at these number, I have put a lot of faith in D&D, so far no issues but that room to coil bind looks close!

53232 is for non disy Rover as Jim N mentioned.

Back in the day D&D simply used the manufacturers part numbers.  I have cross referenced some of them.

I bought my Crower cam (50232) & lifters from Dan LaGrou ( he knew I was going to install it in a 3.9) with a recommendation for a specific valve spring.  A machinist friend of mine opened up the throat of my late Rover heads & installed a set of now NLA Crane springs that had better coil bind numbers than what Dan recommended.  I can't find the paperwork & I do not know if the spring seats were cut deeper.  I don't think the top of the guides were cut down before the new seals were installed.  Don't think there was any info on that back then.  May still need doing.

I do know that my late Rover heads with the throat opened up out flowed my stock Buick 300 heads that were not cleaned up.

I am thinking that the 50232 is too much cam for a near stock late Rover head.  I may step down to the 50231.

Carl, I would keep the 50232. Your 3.9 is bigger than my 215. Plus Crower has 4 degrees advance built in for lower compression, if over 10 to 1 I would retard., On the Rover heads, the valve guides are lower than the early heads and have modern seals. Still use steel inserts in the rocker hold down holes. I'd go for the larger oddfire valves I mentioned above. 75-76 have the long keeper like the Rover. The 77-78 looks like you could use a modern 7 degree. Z28 Chevy valve springs all over Ebay for reasonable price.

Jim, when you do the Rover rockers are you going to use an aluminum tube instead of the springs? If so, you need .015 on each side of rocker on each side of tube. Also, a good number for oil clearance on the rockers. On the TA stud rockers the poly locks stick up a bit and valve covers may not be tall enough. There are 1/2" spacers available on Ebay.

I believe RV-911-16 is an Elgin spring.  Maybe NLA.

This spring has same specs to what I ran with the 300 heads. My Crane springs are no longer available too. Jim B said 300 valves are 1/16" taller.

https://www.ebay.com/itm/393629455167?hash=item5ba624d33f:g:EacAAOSwY49haLZV&amdata=enc%3AAQAHAAAAsB1xbShuI72a26oH1MP3aOSE5xpg6tEpYfiItYW2XZYlzwSkO7NvOxBUsmpTueHhY3JC61HaXaicjmKsZHaPgdldVimHOBrX9%2BpN6LPL4EaCd1ikTr8rRB3sL%2By4B36iMVhSA%2FfBNLLYYwkFGrtfDcHd0qBJfrlvJ%2BOomCeVJFAf%2By80j9RH9E7Pd0q0xIBss%2F%2F5yDZn%2Fg1RYkjbY7X%2FebMsABrctRuGbEldhLFGuuJC%7Ctkp%3ABk9SR_jR9POiYQ

Jim, you could start a cottage industry with beehive retainers and custom rocker setups .Not much performance stuff for the Buick/Rover and if there is seems to be way too expensive.

RV-943X is an Elgin spring.

Isky valve spring specs:

https://iskycams.com/userfiles/files/ISKY-Valve%20Spring%20Spec%20Book.pdf

Only beehives on that list were 1.8" IH so no help there.
On the Procomp rockers fitted to the Rover shafts, I don't know why I couldn't just use the springs that were original. Depending on how things line up I may get away with the existing spacing. But, not much point in doing anything until I get the springs sorted out. I'll try to call Dustin tomorrow and see if he has any ideas. I also need to see how hard the stock retainers are if I'm going to try turning them down.

Don't know about a cottage industry, I seem to have too many irons in the fire already.

Jim

The OEM retainers are quite hard so it looks like the beehive springs probably aren't going to happen. Too bad but sometimes you just have to punt.

So... the specs still hold, maybe there's a single spring that will do the trick:

1.240" dia
~120# @1.560 I.H.
>300# @ 1.010 open

Have to just keep looking.

Jim

Jim, this may be a solution for the beehives. TA has 10 degree keepers for the Buick valves so you would need 10 degree retainers for the beehives.

http://www.taperformance.com/proddetail.asp?prod=TA_V1434C

On the rocker shaft springs. May be ok if you use hardened shim between the rockers so the spring doesn't wear into it. Spacers are better at high RPM for rocker alignment.

The Isky 4005 might work but here's the question:
Since it is a dual spring will the inner spring be OK sitting on the step in the retainer and the seat? That size is .852", the outer spring ID is .925" and the inner spring ID is .690" which means there's .073" of slop and the inner is sitting on .062" of the pilot. A little less than ideal I'd say and it might dance around a little. What do you guys think?

Jim

I have never run dual valve springs.

PAC racing springs catalog

https://www.racingsprings.com/media/wysiwyg/2020_Master_Catalog_FINAL_Web.pdf

Dual springs use a special retainer like these:

https://www.ebay.com/itm/391094779460?hash=item5b0f10be44:g:5I0AAOSwstxVEvv4&amdata=enc%3AAQAHAAAAwE5C9glkkDobz875wvgw3gixc6n%2B%2BD4%2FZTcvS1YtND%2F18EmHgx07vrEkfcHiXSWatFCbPXt44gs2imIlQiUVQtCvejIIef%2BcC%2F2EVGqpoqVQhhOxq5uc6r5C0ViiaXedGSNs1RzgIp5%2FI3EF9ArvvRJD2hwtBrmDOFEge%2Bh0XCNwF9wB%2FwNJCAsOU%2FGxJQOtAp6avbiPjtKRZhtsGd7r%2Blo90OICJavScHjG3v9h%2F6MaeZDjyshxXtaSmJIHNdG%2BoA%3D%3D%7Ctkp%3ABk9SR-DH_f-iYQ

Here are the stock retainers and seats:

IMG_0023.JPG

IMG_0024.JPG

Jim

These from Pac will work but, aren't +.050.

https://www.summitracing.com/parts/rsc-pac-r310-16

Jim, are you talking about the PAC-1231X mod motor spring? I actually think that might work fine with the standard offset retainer. No room for a steel washer under the spring and it'd be .015" tighter but I think that works out OK. No issue with coil bind. It raised the spring load by about 4.4# on both ends to 124 and 284#.  It sort of amazes me that they can do that with a 1.083" diameter spring.

Need to see what sort of prices I can find on that spring but this does sound like a possible solution. Also will have to get the price from TA for a V8 set of keepers (32ea.)

Jim

Jim, The stock springs didn't have a steel shim under them? The small diameter beehive would set on the step around the guide? TA also has +50 keepers. listed for the V6.

http://www.taperformance.com/products.asp?cat=47
You may want to call them to see if they will work with the Rover valves.

The stock (post 1980) sintered retainers are known to break up with prolonged high RPM, with that in mind I wouldn't want to be running high rpm with a higher spring load....
The pre 1980 retainers are machined and reputed to be almost indestructible.  The comp retainers posted earlier are easily available, but are slightly heavier than the pre 1980 retainers.
This pic shows the very obvious visual machined appearance of the earlier retainers. Very obvious vs the smooth, rounded edge appearance of the sintered units.
3DC021A4-0178-46FE-9ECB-10AA7FF73750.jpeg

I am pretty sure last time I called and spoke with TA about the keepers, they said they weren't compatible with the Rover Valves. Now, I may be mistaken, but I was putting an order in with them at the time, and I would surely have purchased them if they were compatible.

Now, here is a suggestion though; A group (bulk) purchase. Personally, I'd purchase at least two engines-worth of keepers, maybe even three. I'm sure a lot more folks would be interested as well. If enough folks got together and requested it, I'm sure they'd make whatever....

Finally, for the springs, the Rover  heads have a diameter of 1.23" in the heads for the springs. There is a lot of thickness under the seats, so it's possible to dig this out more. The Manley 41824 is a well made piece of kit. I have one, but haven't tried it on a head yet.

https://www.summitracing.com/parts/man-41824
https://www.vividracing.com/-p-153101452.html?gclid=EAIaIQobChMIgpCh-pOB_AIVI_3jBx343Qh9EAQYASABEgIc1fD_BwE

Finally, let me add that if there was enough interest, I could get a 11 degree (22 degree included angle) tapered milling cutter custom made, and make a fixture to hold a (10 degree) retainer, then come down and dress out the 10 degree to 11 degree pretty easily.

Lot of options, but I feel like we need to home in on a beehive spring that'll really do the job. Something that'll offer up to .520 lift, but I'm not convinced that a sping much over 300# rate is really needed - especially for a reasonable redline of 6250rpm or therabouts.

The spring pockets will have to be machined for the smaller diameter springs. There were no shims under the stock springs. The pockets could be cut a bit deeper to use shims.

Jim that link is for the keepers, I think this is the one for the V8 application:
http://www.taperformance.com/proddetail.asp?prod=TA%5F1434C

This seems to be the link for the retainers:
http://www.taperformance.com/proddetail.asp?prod=TA%5F1451B

And the link for the springs:
https://www.racingsprings.com/index.php/valve-spring-11368.html

At 120/280Lbs@.550" Dave this sounds like what you are interested in. I could see maybe going a bit higher on the open pressure myself but there's room to shim it to get more pressure if needed. $16 each for the springs seems like a lot to me though, that's $256 for the set. Maybe we could find something a bit less expensive, the costs are starting to add up. This one is for the GT500 and Cobra Jet, I'd expect there are other options.

Jim

Jim the TA retainers are for standard springs not beehives. There are Coyote beehives that are similar, but I don't know if you can get 10 degree retainers that small of ID on top of spring. Coyote retainers are 7 degrees for 3 groove valves and are for a 6mm stem.

https://www.racingsprings.com/index.php/applications/ford/fmod-4-valve-spring/valve-spring.html

Ah, so you were suggesting those for the dual springs then. That makes sense.

How about this:
https://www.amazon.com/Competition-Cams-795-16-Retainers-Beehive/dp/B000N5MWMQ
https://www.summitracing.com/parts/cca-795-16

At .004" larger than the small ID of the spring they will certainly fit.

Jim

Yep, those are the ones. If the Buick keepers fit the Rover valves the TA 10 degree for Buick V8 should work too.

Maybe we have a good combination then. Have to check with TA on the keepers. If that's a go I think we may have something here. We should recap the links once that is confirmed.

Jim

Let's clarify one last aspect. The spring pressure. The load required for a flat tappet cam is less than for a roller cam. This seems weird but the roller cams have a more aggressive ramp angle so they need more spring to follow the lobe and can tolerate it because of the roller.

So while 280lbs of open load is fairly high for a flat tappet, something like 350 might be equivalent for for a roller cam. I'm no authority on this, being kinda new to roller cams and would welcome some concrete data from you other guys. I know it's something of a moving target but...

Has anyone seen performance figures for something like redline vs spring pressures for a roller cam? I'm sure lift also plays a part.

Jim

https://www.motortrend.com/how-to/0512st-valvespring-technology-cylindrical-vs-beehive?galleryimageid=7caa992a-3dd8-4eb5-8c2b-bf924ac43442

Springs used on aluminum heads should run at least a hardened shim to prevent brinelling the softer aluminum material. If you need to reduce installed height, don't stack shims more than 0.090 inch-use a spring locator instead. Also use a locator if the spring diameter is smaller than the pocket.

Beehive vs. Conventional
Even on a relatively mild 406ci small-block Chevy with a hydraulic roller cam, a spring incorporating the latest technology can make a big difference. Westech Performance tested a traditional Comp Cams dual spring with damper (PN 954) against one of Comp's new single beehive springs (PN 26918). The 954 developed 210 pounds on the seat and 523 pounds open, compared with the 26918's 130/318-pound specs. Both springs were installed with titanium retainers and locks, yet the beehive combination was still 52 grams lighter. If the engine's steel valves had been replaced with titanium valves instead, the weight savings would have been just 40 grams.

Overall peak output was virtually the same: 418.4 lb-ft for the 954 versus 416.9 lb-ft for the 26918, both at 4,800 rpm; and 418.2 hp versus 419.3 hp for the 954 and 26918, respectively, at 5,800 rpm. Average output throughout the 2,500- to 7,000-rpm test range varied by only about two numbers. But above 6,500 rpm, the difference was huge: The new-tech 26918 effectively extended the engine's rpm range, proving to be worth 15 to 36 hp and 12 to 28 lb-ft on top. The stiffer 954 did produce more low-end torque because its higher loads were actually bending the other components, effectively decreasing duration at the valve.

If using the longer 75-76 Oddfire 1.62 IN and 1.42 Ex valves you could use the cheap LS beehives. Cut the valve seat a little bigger. You would need 1.75 installed height and would have to shim the rocker stands up.

https://www.ebay.com/itm/184572587719?hash=item2af9622ec7:g:i18AAOSwI~df0DJt&amdata=enc%3AAQAHAAAA8GJmSn7KGk3nCPRNYNDezTzlzq9TibFJWShvIRU2A%2BkNVO3ft6vmPgP9%2FYbHIaWTem3jg0wiUbTr9sRkUDhfOBZBjAp6rDqHVwfJZCB%2BFhgRY%2F0qGt66BLAWMVWEMiMhfE0oxOfJuV9vSkZfGKIKCQJNbqI4bKn3dDv1pK%2BfTy0UXYTXMjA9C3TpXW4bMdpKcqbHkIMAfCSR0wgwxACCfnHEb8HElNDYRPfMFOeGxfa2G%2BdityIXYjCMf3uSj0UnNUX7RPllxoD7FbOLUHsc2HnoNJZR2BZoxBS8v0PVuSlNzCspuSNgs6AwkN6QBYKn%2Bw%3D%3D%7Ctkp%3ABFBMksqS5KRh

That engine seemed to have really high spring loads. But then it is a BBC and has big valves and everything. Rover valves are considerably smaller. I'm also using solid roller lifters which are cut down and are significantly lighter than the hydraulics.

On those Blackhorse springs, by the time you bought the valves and machined the seats to match I suspect it would be a wash.

Jim

What does the cam manufacturer recommend?

Solid roller for a street engine?

https://www.motortrend.com/how-to/1206phr-solid-roller-cam-setup/

They didn't make a recommendation. It's basically a GM grind  done through TA on a blank by one of the major cam companies like Crane or Isky. It was that "Hot" grind suggested by Jim N., I'm having trouble coming up with the name at the moment.

Jim

LT4 "Hot"" cam. Spec for Jim B's cam. Should be perfect in a 350 motor.

https://www.gmperformancemotor.com/parts/24502586.html

Dave, I'll be using Rover heads, so definitely interested in participating in a bulk purchase.

Eric, I think you want to go the other way and machine the 11 degree Buick to 10 degree so you can use aftermarket retaners. Which is what TA sells in the link above. If you use Dave's idea, you are limited to the stock Rover or Buick retainers which may or may  not work with aftermarket springs.

Milder cam than I was expecting, especially when the valve lash is factored in.

Thanks Jim, the whole spring thing is a mystery to me--thanks for letting me know.

Well, TA Performance are closed till the third of Jan

So I guess we will have to wait a little longer to verify 100% if these are compatible with the Rover Valves.


http://www.taperformance.com/proddetail.asp?prod=TA%5F1434C

Cheers,

From what I'm seeing about the LT4 Hot springs, seated pressure should be around 125 and open pressure around 315-325lbs. So I projected pretty close to the mark with 125/350. The PAC-1231X springs are going to fall short by about 50#.

The actual specs on my cam are a little different and the only reason I can think of for it is that Tim at TA chose an in-house grind that was the closest and was designed for the Buick engines. I bought two cams, one a solid and the other a hydraulic. My motor gets the solid cam. They are Grind # 69005 and 69005-B. The -B is the solid grind.

69005
TA 272-82RH
LS: 112
Dur: 272/282
Lift:.525/.550

69005-B
TA 264-74R
LS: 112
Dur: 264/274
Lift: .544/.544
Lash: .016/.018

Lt4-Hot
LS: 112
Dur: 279/287
Lift: .525/.525

So anyway, the Pac 1231X falls short  of the Lt4 springs by about 50# which is not enough to make up by shimming the springs. It means the redline will be compromised. Also those springs are spec'd for a hydraulic cam with a redline around 5800 rpm. Going higher means stiffer springs. How much stiffer? Good question and I don't have the answer. But I don't even know if any stiffer springs for the GT500/Cobra Jet engine are available.

Jim

Jim B, What is duration @ .050?

Jim, IMHO, one of the advantages of the beehives over conventional springs is you don't need the high pressures to prevent valve float. Installed height pressure of 100-120 for flat tappet and 120-140 for roller performance cams is pretty normal. The PAC GT500/Cobrajet springs are an upgrade over their stock springs.I don't think you would have any issue @ 7,000RPM. Sounds like your cams have a little less duration and higher lift than the LT4 hot cam. I would cut the seat low enough to add a shim and have a lip around the spring to locate it. So. you need a cutter just slightly larger than diameter of the spring.

I'm now liking the look of the comp 26981 springs with the 795 retainers.
(again, assuming the TA 10-degree retainers are indeed compatible)

Springs:
https://www.compcams.com/beehivetm-valve-springs-top-1-065-o-d-650-i-d-bottom-1-240-o-d-825-i-d.html

Retainers
https://www.compcams.com/10-steel-retainers-1-095-spring-dia.html


I will revisit my sectioned heads tonight to verify how much can be dug out of the spring seats. Per my notes, the Stock 10-bolt heads have an installed height of 1.579" as a reference and the spring pockets in the head are 0.93" ID and 1.23" OD..



EDIT. I totally missed the post by Jim on December 17, 2022 12:55PM

The PAC-1231X springs could work pretty well. The ID at the top is shown as 0.636" vs the 0.645" of the Comp retainers linked above.  IO reckon that .009" could easily be tweaked with a dremel on the ID of the spring.
https://www.racingsprings.com/index.php/valve-spring-11368.html


(again, assuming the TA 10-degree retainers are indeed compatible)

Dave, I figure with the chamfer on the retainers and the springiness it's likely you could just seat the retainers in the top coil easily on an arbor press, then they'd just stay like that. (Or maybe just with the spring compressor)

I don't have the .050" specs, they aren't on the cam cards. On the LT4-Hot it is 218/228. I know there's a pretty fixed relationship between advertised and .050 duration but can't remember what it was. Looks like about 60 degrees though and I'd expect that carries over to the TA cams though it looks like some of their cams fall more in the 40-60 range. So yeah, I really don't know.

Jim

Quote"...and the production conrods and pistons remained weak."

Do the Rover V8 engines not use a forged connecting rod? I know that the Buick/Olds 215 does.

Dan LaGrou sez the Rover rods are also forged.

"You can use the Buick/Olds 215 rod or any Rover 3.5, 3.9 or 4.2L rods. They all have similar dimensions and the required 5.66" length. Surprisingly, all of these OEM connecting rods are forged, thus making rod failure very rare."

Dave, These retainers are a better fit for the Pac-1231X springs. Strangely same part# though.

https://www.summitracing.com/parts/cca-795-16

Here's a spring that has a bit more load but is rather expensive:

https://www.lethalperformance.com/pac-racing-springs-07-2014-shelby-gt500-high-lift-valve-spring-kit-uses-stock-gt500-retainers.html

I just fired off a Design Request to PAC springs, let's see what they say. Can't imagine they would really have any problem with running off a beehive spring for the Rover V8 but it'll probably come down to quantity and price. I'm asking for a 350lb open load.

Jim

Jim, Those retainers won't work. 7 degree 3 ring. I think 350 is a bit much. Probably 280-300  would be fine for a beehive. Conventional springs require much more to stop valve bounce from harmonics. That is where the beehives excel. I bet the PAC racing springs are all tested to 7000RPM on the Spintron.

Jim, the Comp Cams springs Dave mentions above, instead of 1.7, how about 1.65. installed height. How much room to coil bind and how many lbs more open and closed. You would want to cut the guides down also when you open up the seat. The Modular springs are meant for overhead cam engines and require less pressure due to no losses from pushrods and rockers. You could do an experiment and see how the Buick keepers fit on the Rover valves with Rover retainers compared to the Rover keepers.

>Those retainers won't work.

Probably not, I guess you mean the ones with the Lethal springs? Was only looking at the springs.

You could be right about the spring load, but we'll see what PAC says when they answer the quote request. I told them 7000-7500rpm. Due to the lack of pushrods etc I doubt the spintron results would cross over for the mod motor. Doesn't do to get in a hurry I guess, we're learning more almost every day.

Dang it Jim, seems like every time I turn around I'm having to pull the spring back off that end valve on the 300 head! ;-) But the good news is that the keepers seem to do just fine with the rover valves and retainers. No rock, no play, feels good and I'm convinced they will lock up tight. Good catch on that one. Should be no reason why the TA 10 degree keepers wouldn't work with just about any 10 degree retainers.

On a side note, looks like a set of 9-3/8" Smith's pushrods from my parts cabinet will work fine with the stud type rockers on the TA heads. Just get lucky sometimes. I'll see how they look with the valve open.

Jim

Jim, We appreciate all the work you do! Besides I know you have fun doing it!

Gives me something to do during the dark days of winter.

Anyway I think this makes for a pretty potent SBB/Rover package for the MGB and I'd like to get it finished out. As it stands it's now pretty reasonable to build a pretty potent 5.7L engine based on the 300 block, 350 crank, ex-nascar rods, roller cam, 4.6 heads, and even roller rockers while putting the extra $400 or so of savings from the bellhousing into the engine and then using the RV8 headers and a set of inexpensive home fabricated engine mounts. If you figure the bellhousing savings pay for the cam then the only significant added expenses are the forged pistons and the crank work. And it opens the option for the TA heads later on if desired. I think it's a build that just makes sense. This is really the last piece that is needed for the complete package. You could forgo the 350 crank but then you'd need to come up with a different set of pistons.

I like the fact that it lets you stay in the SBB/Rover engine family while not limiting the performance potential or the option of modern engine upgrades.

Jim

Jim, it looks like your current plan is exactly what I am planning.  I too will use the 350 crank and will need custom pistons and plan to use the 4.6 heads (at least for now).  Any idea what intake and  carb (or EFI) you will use and what the resulting horsepower target is?

Eric, I'm actually building a couple of engines here, neither of which exactly match that formula but both of which are close. The engine that gets the Rover heads is the Buick 340 long rod motor with Scat FHF rods and modified Venolia pistons. (Venolia is no longer in business)

I do NOT recommend the 340 for the MGB. The 300 is a much better choice. But since I've already made the mods that one goes back together with the Rover heads and roller cam as my backup engine.

The stroker 300 has a set of TA heads with beehive springs and titanium valves. Ex-nascar Carillos and Wiseco pistons.

That leaves me with my iron head 2bbl 300 (in the car now) to play with later if i want or sell it if I don't. It will eventually be getting the alloy 300 heads and runs an alloy 4bbl intake and custom Enderlie throttle body with port injectors and COP. Stock valve springs and 4800 rpm redline.

In that configuration the 2bbl iron head 300 which has 9:1 compression probably puts out around 250hp. Just a guess, it could be a little less than that but the torque output is very good. That's with the stock cam. The iron heads also have larger ports and valves. The engine is no slouch by any means and the car seems to keep up with the 302 cars pretty well.

The configuration posted above is obviously going to be more powerful. For one thing the potential redline is going to be in the 7k range so clearly the numbers are going to go up and that doesn't even count the displacement increase. How much really doesn't matter, the power level will be adequate. It should be no problem whatsoever to exceed 300. Beyond that I pretty much stop counting.


The part number for those Wiseco pistons is WD-12883, they work with the Rover heads, 350 crank, and 6.2" rods with .827" wrist pins and use the modern thinner rings.

Jim

Thanks for the information Jim, I appreciate it as always.

Eric

PAC suggested either the  PAC-1276X beehive at 1.67" installed height or the PAC-1202 dual spring at 1.7" installed height.
Either one is going to take some work but should give enough spring pressure to get a decent redline out of a roller cam with around .500 lift. I'm new to roller cams so not really familiar yet with the level of pressure required to follow the lobe profile at a given lift and RPM, but my machine shop guy says he likes to see spring pressure equal lift. In other words 500# at 1/2" lift, 600#@.600" lift and so on. He didn't say what target rpm that was suitable for and I didn't think to ask but I suspect we were in the 7-8K territory.

So with that said, the PAC-1276X @ 1.67" gives 200# seated and 427# @ .550" lift. They require opening up the pockets to 1.300" and making up .110" of height somewhere, maybe with offset retainers and cutting the seats deeper. Coil bind is at 1.070"  so these numbers give .050" of free play, I think that can be shaved probably about .020" leaving .090" to make up. A .050" offset retainer will work and a .100" one might. I expect cutting .050" deeper pockets would be OK and they might be able to go .100" but I haven't taken any measurements. I'll have to check with Dustin on that unless one of you can do it. This seems like it might be a viable option.


The dual springs at an installed height of 1.7" have 187# of load and 484# open. I do not know what the coil bind figure is for that one but it might be usable at a lower installed height. Coil bind is at 1.100 so that installed height again represents .050 of free play and these springs need .140" made up. Probably possible, not necessarily easy.

Jim

Jim, Wow! Those spring pressures will snap a flat tappet cam in half! Those pressures may work good for racing roller cams but for the street 120-140 closed and 300-350 @ .550 lift would be good for a hydraulic roller and 100-110 closed and around 300 @ .550 for a hydraulic flat tappet cam. Check out these PAC beehive springs for a Dodge Viper V10. If installed at 1.7. Also perfect for the bigger, longer 75-76 Oddfire V6 valves.

https://www.racingsprings.com/index.php/valve-spring-11196.html

You would add 20-30lbs closed and about 50lbs more than above for solid lifter cams.

 From Alex's Parts:

Hyd Flat Tappet, High Performance Street- 110 Lbs Seat Pressure.
Hyd Flat Tappet, High Performance Marine and Hot Street- 120 Lbs Seat Pressure
Hyd Roller, Mild Performance Street- 120 Lbs Seat Pressure
Hyd Roller, Mechanical Flat Tappet- 135 Lbs Seat Pressure
These are considered general "rule of thumb" pressures.

The rate on those PAC-1283 springs is 363 lb/in so wouldn't you divide that by 20 to get the increase for .050"? And then wouldn't that apply at both ends? I get 18lbs so if installed at 1.7" it comes to 128/346 if my math is right. (Actually looking at the chart in the PAC catalog it would be 146/346 installed at 1.650" with .550" lift but that only leaves .020" before coil bind, with my Procomp rockers it'd probably be fine. Have to pick up .090" or more somewhere on the installed height. Waiting to hear back from Dustin on how deep the pockets can go.

The price is a bit better (about $60 less) so here are two options, one with higher loads. If the heads were cut to accept the 1276X but the 1283's were installed a simple spring swap later would be easy enough if more rpms were needed. Since the 1.290" spring is LS size it might make sense to go that route.

I'm a little more concerned with what are considered standard loads at .550" lift and how it affects max rpm. Love to see a chart on that. (I'm aware that valvetrain weight is a factor) BTW I'm pretty much done with flat tappet cams. Seen way too many lobe failures.



Jim

To add another data point to the chorus, Erson specced 130/300-325 for a recent hydraulic roller cam.

I'm using 300 heads and the Ferrea Buick 6000 valves, so my spring choices to get those pressures have no relevance to your search, though.

ErsonSpringReco.jpg

Apparently there's not much metal to cut the pockets deeper. Dustin didn't feel comfortable with going .050" so we seem to be limited there. Next option: Offset retainers. We need to look for a beehive retainer with a .100" offset. I think the stems are long enough and if not then lash caps can make up the difference. 0.680" diameter on the retainer, 10 degree, 0.100" offset. I sent an inquiry to CC, nothing back yet. I imagine somebody does have it.

Jim

Jim, Here is another experiment for you. Crane used to sell the same retainers for both 11/32" and 3/8" valves. If I recall correctly the height would go up if using the 11/32" and down with the 3/8". Don't know if it would be enough though. Try one of your other Beehive retainers on the rover valve and see what the difference would be? What would the difference be with the 300/Oddfire V6 valves? I think you mentioned they would be 1/16" taller

Dave was talking about having a Rover cut up head maybe he can answer how thick the seat is. Another thought for another thread, maybe someone who has a 300 head and a Rover head can make a tempate to see if we can copy the Buick accessory mounting on the Rover head by drilling and tapping?

At the bottom of the page, there are 4 pics of a cutaway head.  

https://www.v8forum.co.uk/forum/viewtopic.php?t=12011


Ever see a Rover V8 sawed open to show the coolant passages?  :8

https://youtu.be/g4t3n4H9JFA

Based on those photos I wouldn't have any issue with going an extra .050" deep. Makes the offset retainers easier to find too.

Jim

Or deeper if needed.

Ok, I have some updates.

Reel Steel in the UK and TA performance have both confirmed that there is no valve keeper / lock (aka collets in the UK) that are the Rover v8 valve profile and have a 10 degree angle.

TA never got back to me on a group purchase, but ReelSteel did allude to them purchasing these in 100 engines worth at a time.

So, if anyone is really wanting to run the beehives (using the Rover valves), then I'd recommend a 10-degree chevy cap, and machined out to 11 degrees. I have a very retired good machinist friend who still has his own shop and would be interested in helping with this if anyone wants to be the first.

I was actually spending a lot of time myself in the last 2 days with my heads since getting them back from the shop who skimmed them and re-cut the seats for the larger DW500/DW501 1.4/1.63" valves.

I have both the standard Rover pre 1980 (single spring) machined valve caps/retainers, and the Comp 712. I measured the heights of these relative to the top of a valve, and the Rover ones are .234" and the Comp 712 are a little shorter at .225.

I then measured my current spring pocket heights to the top of the valve, and have 1.802" pretty much across the board, no more than 3 thou variation anywhere! This is nice work from the shop that did the seats....

So, 1.8 minus 0.225 = 1.575" installed spring height. Clearly that's not going to work as all the springs in our range are 1.700 installed height.
So, I had already purchased Manley 41824 spring seat cutter, and trialed it on a scrap head. Works very nicely.

I have already purchase Comp 980 springs and these look to be a good general fit for the application.

How deep can we go on the pockets? Well I've cut up heads previously, and .332" is the min material thickness across any of the heads from the factory spring pocket to the water jacket. This is on the exhaust; the inlet is definitely thicker. You'll note these are a mix of the earlier heads and the later 10-bolt. The easiest way to tell is in the height of the "yump" of the bottom of the port; the 10 bolts are a lot lower than the 14 bolt heads; while this gives more initial flow, it becomes less of an advantage as you start seeking higher flow figures. I suspect this change was to put more tumble than swirl into the mix, presumably for emissions.

As I'm using the Crower 50233 that has 0.488 inlet and .501 exhaust lift, and the comp 980 springs are rated to .490 max lift, I'm actually going to run an installed height of 1.700 for the inlet, and relax it to 1.72 for the exhaust. Hence the inlet will meet the comp figures of 243lb at 0.49" and 92lb seat pressure, but the exahust will be 243lb at 0.51" and 85.8lb seat pressure. I don't think the loss of a little seat pressure will be an issue, especially as the valve is lighter than the inlet.

My seat pressures are a lot lower than others quoted here, but I just don't think I need that much pressure for the waisted stem valves at a 6200RPM redline. If i was going for 7000rpm, sure - but that's not what I'm planning for.

So, I will need to machine the inlet spring pockets to increase the depth by 0.125" and the exhaust by 0.145". This should still leave just under 3/16" material above the water jacket. Its not as much as I'd like, but that thinnest part of the casting is only around 90 degrees and it gets a lot thicker in the other 270 degrees.

Really, the best solution here is to use valves that are anything from 0.10 to 0.20" longer than the Rover valves (and it gets you into common valve locks/keepers/collets. I now fully understand why longer valves are often listed. Of course longer valves also means spacing out rocker gear, and then longer pushrods, so it all suddenly gets very pricey!!!!


valve1.jpg
valve2.jpg
Valve3.jpg
valve4.jpg

10 bolt head exhaust section.
valve5.jpg

Dave, Great work! Did you see the Dodge Viper V10 springs I mentioned above. They are for 1.75 installed height. These are also 1.7 height:

https://www.summitracing.com/parts/CCA-26981-16

Those and a few other springs would be highly suitable...
But the pressures still seem a little on the high side unless you are going to be turning some big RPMs or using heavier valves???

I'm just flat running out of time right now unfortunately, otherwise I would be purchasing a 11° Carbide mill and Setting up to machine some retainers to 11 degrees.

Maybe on my next set of heads!

Well, here is a potential issue...

I drew it up in CAD to better visualise it (click on the image below and it'll open in a new window).
While Beehives are great, there is only so much that can be done using the stock rover valve stem dia and the matching 11 degree locks / keepers / collets. These 11 degree jobbies sure take up a lot of room :-(

Two retainers shown, the left is the comp 712 (incorrectly listed as 980), the right is the pre 1980 single-spring non-sintered Rover item.

The beehive spring shown is the Comp 26981 with the .650 ID / .825 OD at the top of the spring, and the 1.24" OD at the botttom.

I have positioned the spring to line up with the standard spring surface.

As can be seen, lots of interference. While we could move the spring lower, this would lose installed height, and no way to get this much back

Maybe we  should be looking instead at the next dia larger for the springs (1.375 ish? to get a larger ID at the top?



beehive.jpg

Dave, Could you do an image of these retainers if reamed to 11 degrees?

https://www.summitracing.com/parts/cca-795-16

Dave, Is this the reamer we would need?

https://conicalendmills.com/cutting-tools/special-application-end-mills/tapered-end-mill-carbide/11-degree-carbide-tapered-end-mill/

Hey Jim,
It is indeed a 11-degree (22 deg included) but you need one with a major dia of at least .590" dia (and a minor dia of .400), so none of those will suffice; it'd be a custom piece.

There isn't enough info on the comp site to make a drawing unfortunately.

I can purchase a set on amazon and measure them up to see how they would work (and return if its a no-go), but if you assume that you would use a reamer and set it up to just clean up at the bottom of the existing 10 degree, you are radially increasing the diameter by approx 8 thou at the height that the top of the spring would be sitting (or 16 thou on diameter)!

I think though, there still isn't enough installed height - you're still going to be digging material out of the seat pocket in the head.
I have seen offset retainers in the past; not sure if they were for 10 degree though; obviously the further up the top of the spring, the wider the keeper/lock/collet so you start losing diameter...

I just confirmed with Tim that the 10 degree keepers that TA sells have in fact the Chevy type groove. Dave was right, no help there.

Still no luck I suppose on the tapered carbide reamer? Might be easier to find in the reamer category as opposed to the end mill category.

Creating a carbide tapered reamer is not a minor undertaking, but not impossible either. For this job I would start with about a 3/4" round stock in mild steel, cut the taper, make relief cuts to locate the carbide, and then braze pieces of carbide in position. Then back to the lathe to grind the taper with a tool post grinder, followed by grinding the relief angles. Using 3 edges would give a self-centering action although it could also contribute to chatter.

Finding the pieces of carbide is as much a challenge as anything, however here is one source:

https://www.carbideanddiamondtooling.com/search?query=stb26a

They would need to be roughly about 3/32" thick, .200 wide, and 5/8" long but the above ones should work.

Jim

I ordered some of the carbide pieces, after they come in I'll see about making up the body of the tool. I have everything else here that I need to make it.

Jim

Hey Jim,

II just ordered some of the retainers and will draw them up and verify there is enough meat in them to make this happen.

Cheers

OK Dave, if it looks like it'll work I'll cut your retainers if you'll send me a second set for my own use. Does that sound fair?

Jim

Anyone have cut-up pic's of the 300 alum. head ? I have such a head.
                                                                                                                  Art.

Jim, That sounds fair.

Here is the latest CAD..
The beehive Comp 26981 spring is shown on all (height is adjusted to suit.

The one on the right is the stock pre-1980 cap / retainer - note the beehive spring is overlapping as its designed for a 1.25 spring.

The Comp 712 (I just realised I still have identified as 980) is pretty much the same as the stock one; it just sits a little higher (see previous pics).

Both the right two would need (for a 1,70" seat height) the spring pocket lowering by approx  .142"


Middle pic is a proposal I had to modify the Comp 712 (again, wrongly identified as 980) to take the beehive spring. I have a friend with a CNC lathe that could be set up to have a mandrel chucked up, and machined with a 11-degree taper, and threaded, such that it can repeatedly machine these to suit. This would need 0.105" machined out of the stock pocket.

The second from left pic is just a reference, of the comp 795 retainer - obviously wouldn't work as the angles are not matched,

The left pic is the Comp 795 modified to 11 degree. As this would raise the height a little more, so needs only .072 removed from the spring pocket.

The next post will have all these pics (except for the stock retainer as this is pretty much the same as the 980) in better detail.



latest_valve_cad.png

Close-up pics for reference.

The last one is the modified 795. The real question, is what are the thoughts on so much of the keeper being outside of the retainer?
See the following post for a more detailed image with dimensions (only four images per post permitted)...


comp_980_1.png
comp_980_2.png
comp_795_1.png
comp_795_2.png

As can be seen here, the top 10 thou and bottom 20 thou of the stock rover valve locks / collets have a slight chamfer, so you already lose contact surface area. But still with the modifuied 795, you would have just under 70 thou sticking out the bottom in fresh air. Is this bad? I just don't know....

As always, click on the image and it'll become a lot larger...
valve_lock_collet_detail.png

Dave, I like the 980 modified the best. On the 795, what bothers me is the valve tip is so close to the retainer. If it was milled flat on top it would be better. The keepers are a lot longer than most and the part below the retainer won't hurt anything.

Hey Jim,
Well maybe here is something a lot simpler.

If we chucked up the comp 795 in a CNC lathe on the 0.639" dia, and located up to the spring face, it can be used to bore the angle to 11 degrees and face the top, and it'd be quick and easy to do all of these.

It will still need some material digging out of the heads, but that's not a surprise....
comp_795_3.png

I don't really see any problem with the 795. As long as the valve tip sticks out any above the retainer nothing is going to hit. The part of the keepers that stick out below won't hurt either as long as they don't hit the seals.

Jim

Well, I guess I'll speak with my local shop and see what they want to machine these on their Haas lathe. After initial set up we're talking less than 2 minutes each, so can't be all bad.

Yep, let us know.

Jim

What is the diameter of the valve stem at lock ? The stem is 11/32" but it is thinner at lock position. I was just thinking if it would be possible to modify the smaller 7 degree 5/16 locks by removing the tang. In other words make it look like Buick/Rover lock ?

Jukka,

This is the dimensions of the valve and locks of the stock rover setup.
stockvalve2.png

Jim,
Well the shop I spoke with suggested it would be a better idea if they did the setup, and I stood by the machine and ran the parts. Basically, for the price of a case of beer to them, I can get the 795 modified to the 11 degree angle. I'll obviously extend the offer to mod a set for you as well...

They also have a diamond wheel and spin fixture, so are happy to modify my manley 41824 seat pocket cutter to a slightly smaller diameter (it currently cuts 1.265 dia which is a hair too large for my liking) ... If you don't have a pocket cutter, you are likely to need one.....

So, I'm going to do a little more gathering of the other parts (like confirming and purchasing the springs I'll be using) but it sounds like we have a plan.

The ONLY thing I would want to add, is that based on the drawings, modifying the 795 to 11 degrees does reduce the cross-sectional area at the narrowest part from 43 to 37 thou. This then becomes 87% of the cross-sectional area it was previously.

comp_795_4.png

Jukka  has a good idea! Here is a pic of a 7mm 10 degree you could use 7 degree also. You could use a retainer as a fixture and drill to remove the ridge. I think it should work fine.
rsc-pac-l8005_lw_xl.jpg

interesting. Now I understand the thinking.
0.277 inch is 7.06mm so yep,

For a fixture, you'd need to stop them spinning, and maybe also add something to space them apart as they aren't meant to touch, and I'm sure unless using an end mill, they will drag up and out as soon as you drill them.

I feel that something more like this  would be better, where you cut up half a retainer, machine it just a little past half way so the lock sits flush, and put it against a block (yellow) that has a notch in t for clearance (maybe tack them together at this point?) and use a clamp (purple) to hold them and use a 2-flute end mill to remove the offending lump?

What's the p/n for the 10-degree 7mm???

collet_clamp.png

Dave, here you go:

https://www.racingsprings.com/index.php/valve-spring-retainer-lock-5090.html

Dave, I was thinking of just clamping the retainer in the drill press vice. Dressing a 9/32" Cobalt bit down to .278". I think the taper will stop any spinning. You just want to take the ridge off and hone it out a little. Once drilled, shut off drill, lift up and remove locks.

I am sure if drilling as a pair you'll want to put a known thickness shim or gauge wire between the two (on the flats) to space them apart, and press down to seat them and prevent spinning.  Rethinking it, that would probably be pretty easy to achieve, just a little fiddly with the shim, but totally do-able. Doing as a pair would stop the drill walking and be a LOT quicker of course!

McMaster has metric colbalt drills I'm sure. I do have a few metric R8 collets so will probably just use my mill.

How great is this that the .277 is right there at 7mm?
Nice idea Jukka !

That is what I hoped the TA locks were! Actually, if you use a 7mm bit and they are touching, they won't be when on the valve stem because it is slightly larger diameter.

Good idea but it will be fiddly and tricky to do. That spacer between the two halves will have to be an accurate thickness so you don't cut into the rest of the bore and your clamping device will have to press the halves into the taper pretty firmly. You might make your spacer as a long tab that extends out the bottom and just drill away the center of it on the first set, then deburr and continue with the rest. That way the bottom part would make it way easier to insert as a single shim rather than two individual ones. Might want to make the shim out of aluminum.

But how to clamp it? Maybe something like a big nut that the retainer will fit into? Then a hollow bolt in the top that will press only against the keepers? Drill through the open center of the bolt. Has to be a step in the nut for the retainer to sit on. Draw something up Dave and I'll throw out some more ideas.

Jim

I'll throw something together in 3D to make it easier to visualise.

Based on my playing with locks in the past few weeks, I'd have thought we're only talking about 4-8 thou a side. That'd be not too difficult to cut into 1/16" wide strips. If cut to 3" lengths it'd be pretty easy to slide in there.

Jim or Dave, You guys can check the gap on the stock Rover pieces.  For a shim, a pop or beer can is around EDIT.004 thick so a piece doubled would be about .008.

Yep, I'll check out the gap this evening, but the reality is the valve locks that we will end up using / modifying for use need to be put around thee appropriate diameter valve / pin gauge and their gap measured.



I'm about to order one each of the PAC-1231X and a few pairs of the 10-degree locks that I can do some experimenting with.


I had seen this mentioned earlier, but hadn't t appreciated the 1231x as being a 1.575" installed height, and having up to .550 lift, and 291lb rate, which makes it about perfect for me with a 50233 cam and hydraulic lifters.
EDIT - the 1233 spring is 7 degree only as it has a smaller ID so I'm not bothering with that...

I'm also going to order a pair of PAC-R310 to see how they compare in the installed height to the Comp 795 as they appear to be almost identical to each other.

I do like that PAC lets you order onsie/twosies of everything very easily.

Finally, I wanted to add this pic as a reference of where my measurements are at. The important things to note, is the 1.80" dimension is larger than it typically would be as there was a little pitting on one of my head seats, so i told him to just cut them a little deeper (rather than replace the seat) as it'd be beneficial for me to have a taller installed height anyway.  The other thing to consider is the yellow dimension - I am running shortened guides and these were pressed further into the head, to keep the seal off the keepers.  
It is generally regarded the later 10-bolt heads (as I'm using) are only good to .450 or so of lift, but I found even that puts the top of the seal into the reduced diameter of the stem, so I went a little deeper to compensate....

Finally the 1231X springs are 1.083/.720 at the base, so the head will need modifying (of the 0.832" diameter) to allow these to sit where they need. The manley seat cutter i had mentioned previously only cuts to .742" ID, so I'll need to find another option for that...

reference.png

Dave, Sounds like fun!

I believe the gap between the two keepers is going to turn out to be bigger than you think but I haven't tried to measure it yet. I would expect to see something closer to .010 - .015" per side and maybe even a bit more. It's not a place where a close tolerance is needed. The overall length of the keeper is also somewhat important and it would be a good idea to look at the top and bottom edges of the bore to see how closely they match the original keepers. The top corner in particular needs to have a larger radius than the inside corner at the top of the valve groove.

Jim

interestingly there is no chamfer on the top of the rover keepers...  It doesn't seem right, but that's how it is, and how I've shown it as a gap in my CAD models. Try it on a few heads yourself - theoretically, there should be no gap atop the keeper, but you can probably slide a feeler gauge in there a little ways.

Again, my experience is all on the 10-bolt heads.

8 thou per side is approximately where the rover keepers are sitting at.

Pac Springs online store has been down for a few days, so i finally called up today and ordered over the phone.
I got very confused as the guy on the phone told me the 310 retainers wouldn't work with the 1231X springs, and I should instead use the 311 retainers.
I got confused, so said I'd call them back, and after checking my notes, I'm still a little unclear. The 311 has the same 0.640 diameter as the 310, but the 311 is 7 degree, compared to the 10 degree of the 310.
Now, the ID of the top of the spring is .0.636, which means its unlikely to fit the retainer, but I'm not sure what's going on there?  I'm not adverse to taking a small stone in a die-grinder and relieving the ID of the top spring coils a few thou radially to get it to fit over a .640 diameter.

Anyways, I just called back and ordered what I wanted. End of the day, I like the 1.575 installed height of the spring, as itt'll reduce the need to dig lots of material out of the head.

Dave, I think he thought you were using the stock valves for that spring which is for 7 degree keepers.

Dave, you're right about the square corners on the keepers. Or such a small radius you'd have to measure it under a microscope. Should be fine.

The retainers will press into the top coil of the spring. The spring will expand slightly to accept it and then grip. No worries there.

Jim

Thanks Jim and Jim! That all makes sense.

I must say, I really appreciate all the good grounded conversation in here  :-)
Makes a refreshing change from the FB pages that seem to have killed a lot of the forums.

Dave, I'm having trouble finding a small spring seat cutter for that spring. That spring is meant for a DOHC Ford Mod motor. You would think that there would be one. Comp Cams has a 1.1 OD inside valve locator for a .510 valve guide. What is the OD of the Rover guide? We may have to go back to the Comp 26981 spring

The Dodge Viper springs set at 1.66 will give the higher pressure Jim B needs for the solid cam. Meant for 1.75 installed height and .600 lift at 1.66 it is good to .550 with .030 until coil bind.

https://www.racingsprings.com/index.php/valve-spring-11196.html

The manley 41824 (that I've mentioned a few times) is a .742" internal on the spec sheet.

I need to do another trial cut on a scrap head to figure out what it actually cuts to, but its likely close.

Should have the springs in my mailbox on Friday or Saturday, so I'll report back more on the weekend.

Here are dims that should help you make a decision....

reference2.png

Just to clarify, Dave, the dimensions in your last drawing are for a stock Rover 4.0/4.6 head.  Correct?

That is measurement for my refreshed 10-bolt heads (1994 on). If i was to guess, you can probably reduce the 1.80 and 1.566 by 20 thou or therabouts.
I do have a 1980 SD1 head, and a 10-bolt head in my shop; I'll measure both over the weekend and make a drawing as a reference.

I have a set of both the 4.0/4.6 heads & a set of 3.9 heads (& 300 heads).

Dave, could you do the diameter of the valve guide under the seal too. Thanks!

Just a FYI ,
The Engine Masters series has an excellent entry level episode on valve springs.
If you find yourself lost on this message. It will clear off some of the fog.
I get the program locally on the Discovert Channel.

Live like you mean it.
Fred

Fred, could you post a link perhaps?

Jim

This video is pretty good:

https://duckduckgo.com/?q=valve+spring+and+retainers+locks&iax=videos&ia=videos&iai=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dv28-V-lvKPM

It's on the CTV network, Discovery Velocity channel, Engine Masters, season six episode 26.
Not sure if this link works, but give it a shot.

https://account.bellmedia.ca/login?lang=en&action=signin&fallback=https://account.ctv.ca/sso&service=ctv&continue=https%3A%2F%2Fwww.ctv.ca/loginflow

Appreciate that, it should help anyone following the thread.
Here is the spring I'm considering:

https://www.lsxceleration.com/pac-rpm-series-beehive-valve-springs-pac-1276x/

If it is installed at about 1.6" seated pressure will be just under 200 lbs and it will allow .550 lift with a little over 400 lbs open. That should work well with the (relatively) smaller valves in the 4.6 head and the solid lifters I think. The pockets will have to be opened up a bit.

I believe I'm ready to order springs and retainers.

Jim

Jim, You may want 1.65 installed for .550 lift with .030 before coil bind. 1.6 only gives .530 before coil bind.

Yep you are right. I'm back to looking for .050" retainers. Any ideas on that? (or even .100" retainers for that matter)

Jim

Jim, just Chevy style for the single groove. The short Rover valves are the issue. The longer 75-76 Oddfire valve would work fine plus they are bigger, 1.62 IN and 1.42 EX. Would need 2 more IN and 2 more EX.

http://taperformance.com/proddetail.asp?prod=SRV%5F231A

So, what is it, the retainers are not available in +.050", only the keepers are? So then I'd need to modify +.050" 7mm keepers by removing the locking ridge?

Just want to be sure what the plan is before I order the parts.

Jim

Jim, There are some double spring retainers that are +.050 but not beehive. most are 7 degrees too. Found this one .731 ID measurement:

https://www.compcams.com/10-steel-retainers-1-185-spring-dia-3.html

Why not just machine the needed keeper groove into the valve stem and use the 7mm keepers.
Almost any lathe could do it in just a few minutes.
If you took the end of the valve stem down to 7mm you could put the keeper groove in a better position to accommodate your installed height.

I was wondering how using the 7mm keepers affects installed height? Stands to reason being for a smaller diameter valve that the taper of the 7mm keeper should be a smaller diameter than the taper of the OEM keeper and that would let the retainer sit higher on the valve stem. Has anyone looked at this? It could make it a whole lot easier to use the available beehive springs.

Jim

I think Dave was waiting on receiving them to experiment with.

Pac carries beehive retainers to fit their 7mm keepers.

Yes but if the 7mm keepers are used with the 11/32" retainers like the CC 795's it would seem likely that they would sit lower in the retainer. How much lower is the question. We think if we can remove the projecting lock they will work with the large groove 11/32" valves. This would let us use a taller spring like (possibly) the 1276X.

Jim

Well as an update I only just received the sample retainer snd locks yesterday, and still haven't received the spring. Fast shipping would appear to not be a PAC attribute. I'll measure up tonight.

As regards modifying the valve stem, I don't have tooling to hold it in my shop lathe. May get away with the exhaust but can't put it in a 5c collet as they are only a 1" ish ID as I recall. I'd really need to make some large soft jaws. If I hadn't already purchased these valves, and had them back cut and everything else for my heads, I'd probably just be getting slightly longer valves and custom pushrods . I may still go that way if the machining of the locks becomes tedious - or if it's just going to be difficult to get adequate installed height.

well, here is the results of the PAC-L8081 keepers and the Comp 795 retainers.

So, the Comp 795 is basically the same as the PAC-R310. The 792 is 2 thou smaller on the spring ID dia, and 10 thou larger on the major dia compared to the PAC-R310.
They both have an identical height from the top of the keepers (around a 7mm dia) to the top of the spring.
Basically, there is very little between them.

The PAC-L8081 are listed as a +.050" height. I wish I'd have also got a few of the PAC-L8080 but for some reason didn't....
The L8081 are shown as a +.050" height, and the L8080 are +.100"
Based on the drawing below, this would put the Comp 795 / PAC-R310 at basically the same height as the stock retainer.

So that may be of some help.

I really can see the benefit of the longer valves now..... An extra 1/8" would be night and day in solving many of these issues.
10_deg_options.png

Dave, You drilled out the ridge in the keeper so it fit the same as stock? The + .050 or + .100 would only make a difference if you grooved the valve?

Ugh, yep. That's what happens if you're tired and try to get something out without thinking properly!!!!

You're absolutely right, I got myself mixed up. That only refers to the keeper groove positions in the keeper, so ignore all the stuff about trying different keepers.
The important reference is the dimension showing how much lower this ends up compared to the stock setup. It's not great.....
I think I'm back to modifying the retainer to 11 degrees.

Still need to figure out a spring pocket cutter mind.... The Comp 4716 is 1.320 x 0.630. That would allow me to grind the ID out to ,720 and the OD down to whatever.

This overlay shows the difference - basically the 11-deg Rover keepers are smaller on the taper dia than the 10 deg keepers.

KEEPER_OVERLAY.jpg

Well I didn't expect that. Going the wrong way isn't it? OK well my pieces of carbide came in, it looks like making the reamer is in my future. Might as well order the retainers I guess. Honestly though it'll be less fiddly to ream the retainers than the keepers. At least that's a pretty simple lathe or drill press operation once the reamer is made. You could single point it in the lathe as well of course and that would be an easier setup once the right tool is in hand, but overall a slower operation. Might be possible to cut deeper to get  more on the spring height also. Provided there is enough wall thickness this sounds like the way to go.

Jim

Jim B: Agreed.

I'm personally back to looking at the Comp 26981 spring. While the install height is not quite as favorable as the PAC 1231X the base of the spring matches the seat pocket cutter I already have....

Plus modifying the Comp 795 to 11 degrees means I need only dig out 70-80 thou from the seat pocket.

As regards your concern about wall thickness, scroll back to page 8 and look at the post from January 23, 2023 10:34AM. I have detail on the reduced wall thickness and percentage reduction on cross-sectional area.

Are you going to set an indicator stop on your machine so they machine to the right height?

I'm probably just going to take my machine shop up on their offer to stand and operate the Haas lathe and knock all mine out. I'll also knock the top ridge off like in this image. I can just as easily do a set for you if you are interested?

comp_795_5.png

Dave, depends on the cost but yeah why not? I don't see any need to machine the top of the retainer though. It's below the valve tip and the roller is below the body of the rockers so there's no way they are ever going to make contact.

Jim

I've read you want .050 rocker to retainer clearance. Everything moves around after 7000RPM.

Comp Cams Beehive specs:

https://www.amazon.com/Competition-Cams-26915-16-Beehive-Spring/dp/B000CIUBHW

Bottom of page 26918 would work for Jim at 1.65 height.

Thanks Jim, not bad. Would need to cut the seats .134"

Jim

Jim, My math was wrong . I used the lower coil bind of the other springs.1.1 coil bind. 1.68 installed gives .030 until coil bind so would have to cut .030 deeper.

Please beware of Comp springs on Amazon.
I ordered up a set of 26981's from what looked like a legit seller.
They arrived in a used comp box with photo copied instructions.
A quick check showed that they were nowhere near what they should be.
They were returned and reordered. Same result.
Ordered finally from Summit. Got what I actually ordered cheaper than the big A.

Cheers
Fred

Good point.
These are a lot cheaper than anywhere else. Amazon really sucks about this kind of stuff.

https://www.amazon.com/Competition-Cams-26981-16-Beehive-Spring/dp/B0014F35M0/ref=mp_s_a_1_1?crid=2YKL5BXXCGY4S&keywords=comp+26981&qid=1675457057&sprefix=%2Caps%2C109&sr=8-1&ufe=app_do%3Aamzn1.fos.f5122f16-c3e8-4386-bf32-63e904010ad0#aw-udpv3-customer-reviews_feature_div

Figured I'd throw this up here as I'd already created it as a reference of the PAC-R310 to the Comp 795.

I would say the Comp 795 is the better option for what we are trying to do (machine out to 11 degrees), especially as the rover keepers would be hanging out the bottom of both, but will be twice the stick-out on the PAC.

 I also screen-shotted this useful side-by-side comparison and figured I'd post it.

RETAINER_COMPARISON.png
comp_beehive_comparison.gif

Also this:
https://www.lsxceleration.com/pac-rpm-series-beehive-valve-springs-pac-1276x/

    PAC-1276X
Type:
    Beehive Valve Springs
Spring Diameter Bottom (in.):
    1.290
Spring Diameter Top (in.):
    1.040
Spring I.D. Bottom (in.):
    0.906
Spring I.D. Top (in.):
    0.650
Max Lift (in.):
    0.650
Load (lbs) @ Installed Height (in):
    150 @ 1.800
Open Load (lbs) @ Open Height (in.):
    420 @ 1.140
Coil Bind (in.):
    1.070
Rate (lbs/in.sq):
    409

So far the best prospect I've run across for the solid roller cam, installed at 1.664 for .544" lift and .050" from coil bind, 205 lbs seated, 475 lbs open. Its a bit more than I was shooting for but right in the range my machinist thinks is appropriate for this cam. Requires the spring pocket to be cut .104" deeper and .060" larger in diameter.

Dave, the dimension I am the most curious about on those retainers is the  thickness of material at the thinnest point of the inner wall of the taper, where the shoulder of the spring seat most closely approaches it. Does your cad program allow you to easily dimension that thickness? If we are able to thin that section of the web any at all it will decrease the depth of cut in the spring pocket at a ratio of roughly 3:1 so that's worth keeping in mind. Probably more critical not to go too thin in the retainer but if we had over .050" (I doubt that) we might chance it.

Jim

Also Dave as I'm sure you are aware, you will have to allow for the radius in the retainer where it meets the collet in your lathe to get good repeatability on your depth of cut. Just a friendly reminder. If you are using a depth stop in the back of the collet it shouldn't matter of course.

Jim

JimB
Scroll back to page 8 and look at the post from January 23, 2023 10:34AM.
I have detail on the current (10 deg) and reduced (11 deg) wall thickness and percentage reduction on cross sectional area.

As regards the retainer machining (from 10 to 11 degree)... it will be done on a Haas CNC lathe.
The first one will be Dykem'd and set in the Chuck gripping on the .640 dia and pressed into the chuck while tightening - basically axially seated on the surface the top of the valve spring contacts. I will use a bestest indicator to zero the tru-adjust chuck so it has no run-out, and likely try a few more in and out to see how well they all seat in the chuck and evaluate the run-out.

On the first one. I'll take very slight cuts (at exactly 11 degrees) and increase the X (cross feed) offset till it cleans up. I am about to purchase a selection of ball bearings to use as a way of very accurately measuring the gauge depth of the taper, and will use these as a checker; and also use them to more perfectly measure the existing taper gauge depth (I've been seating pin gauges in there thus far).

Once the first one is right - we will be able to repeatedly machine all the others exactly the same - as well as they are repeatable to each other - and assuming the chucking is repeatable. Hopefully the earlier test on run-out repeatability will determine I can hold an acceptable amount and not have to adjust the chuck on each one!

I see. 5 thou isn't likely to matter but I wouldn't want to go any thinner.

I'm assuming that HAAS uses 5C  collets which have a very sharp corner at the nose. Fine except for when you have a radius like the 795's do. That can throw out your repeatable clamping enough to matter.
But, all 5C collets accept an adjustable back stop and most people who use them have at least one of those so there should be one lying about in a handy spot. Just have to make sure the end matches the bore and leaves room for the boring tool. Sometimes an intermediate plug is used and would likely be handy here.

That machine should do a fine job and be quick about it as well. Pierre had a Hardinge chucker and later traded it for the CNC version. I honestly think he liked the old mechanical one better.

Jim

Good call Jim.
Suffice to say, although I did an apprenticeship before moving pretty quickly into engineering (but still do a lot of machining at home) , I will be relying on the journeymen machinist/owners of this tool & die shop to be making the setup for this operation. They understand I'll be making quite a few pieces, but that they need to be accurate and repeatable.

Personally, I feel like the best place to be locating axially against is the spring contact face.
 I may just machine & surface grind a thin washer (in advance of going to the shop) with a chamfer on the ID that I can use on each piece to keep away from that radius.


Edited to add a little more:
As I mentioned, I've got some ball bearings coming my way that I'll use to verify dimensions on the existing 795 retainers to set the gauge dia of the taper. The way I've measured them thus far is to use a pin gauge on the 795 (and all the other retainers I've drawn) at the .4560 reference dimension, but this is not assured obviously as there may - or may not - be a relief in the angle at the end. It also assumes the stated angle they are machined at, is perfect....

I'll measure at least 10 of the 795 retainers to get a good data set and perfect the drawing as needed.  This technique will obviously allow me to verify the post-machined 795 pieces.

I will also use this "two ball" method to verify the exact angle of the rover keepers - both the pre 1980 machined units and the sintered ones from the 1994/1995 serp heads i have in my collection.
comp_795_6.png

Sounds reasonable. If you were to check the dimension from spring seat to the bottom end I'd be willing to bet you won't see more than a thou or two in a 32 piece batch which would make the back stop perfectly fine to use. It does allow for a stack up of tolerances though. Your washer takes more time to load and unload and it has to locate on a taper (the nose of the collet) unless it is a very close fit. It could work OK but if there's an indicator stand available it would be quicker to just inspect that dimension and eliminate the extra step. I have no doubt those guys will get you set up the best way.

I'll wait to see how this all turns out before I order the springs. Hopefully the end result will be as good as we are hoping.

Jim

Looking for input from you guys...

What do you REALLY think we need to run for seat / open pressures on a 6400 RPM Rover V8 using a Crower 50233.

Crower states exactly the same 120lb / 290lb numbers for everything from a 50227 with 402/420 lift and 4000rpm redline to the 50233 with .408/501 lift and 6500 redline... So it seems obvious they just pencil-whip these numbers.

Most of the published data points we see regarding flat-tappet valve train spring pressures are related to the SBC. Of course the SBC has valves  (I'm guessing), 3/8" larger dia than the largest oversized 1.63/1.40 valves that can be installed into the seats of the stock heads.  Those larger valves have to be at least 50% more mass of the Rv8 valves?  I'm pretty sure the historic SBC numbers were asol with stock (heavy) retainers and non-beehive springs...

Anyway,
These are the springs I was looking at for my engine. I'm now erring back towards the Comp 26981 - if anything because they clearly WILL work, and I already have the Manley seat cutter that'll work for them - and I just need to get moving on this!!!!  Any other thoughts or suggestions?


oh, and if anyone is interested, I'm happy to share my excel file so you can play with the spring installed heights of the five comp beehive springs pictured several posts above in the image (along with a few PAC springs) to easily see the seat and open forces.
SPRING_SELECTION.gif

Dave, I think the 26981 at 1.7 is perfect for the cam you have. When you cut the retainers you may have less seat cutting to do if you can get +.050.

Well I've decided to pull the trigger on the PAC-1276X springs unless anyone has seen a better candidate.

https://www.lsxceleration.com/pac-rpm-series-beehive-valve-springs-pac-1276x/

I'm counting on Dave and Dustin to make them work. How is it going on the retainers, anything new for us on that front?

Jim

Well, I'm back off my honeymoon, but work was crazy busy first week back, so I'll be going to the machine shop this coming week to machine the 795 from 10 to 11 degrees.

In the meantime, I decided to do a little more investigation into the angles of retainers in the evenings...

I used the ball bearing height approach as shown below, using "amazon special" metric and inch assortment boxes. It was interesting seeing just how far some bearings can deviate from their supposed perfect diameter, but actually used the true diameters in CAD, noit the theoretical diameter.

For the retainers, I lightly cleaned the taper using very fine emery to remove any high spots, then cleaned with scotchbrite. Obviously, the rover retainers were used, but the Comp ones were brand-new.  I measured four samples of each; and the dimensions were all very similar across each sample. I also re-verified the zero at the end, and re-verified the dimensions on random samples to validate the Gauge R&R and each time was no more than 1.5 thou max variation (usually less than 1 thou).

Anyway, this is pretty interesting. The "machined" rover one had a lot of variation, but this could be seen as the various machining marks and past use keeper contact points.  The Comp 795 was amazingly consistent, but the Comp 712 was confusing; how can something CNC machined be so poor? Maybe this is made on the older machines at Comp?, or outsourced? Regardless, it's a little disappointing.

But even if you look at the angle measurements (oops, except for the 795 white angle, - its X to B in that example as the .437 ball is too small)) the angles are all over the place.
And these angles deviate from the 22 degree included angle (11 degree single angle) of the Rover valve keepers......
EDIT  -just to clarify, I show all these dimensions as "included angle", not the one-side angle as these are typically reffered to; just half the numbers if you prefer)....

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So, now I wanted to verify for sure, what the angle is for the Rover Keepers / locks / collets (depending on what part of the world you live)!!!

As I have a DRO on my mill, I decided to make use of that, so set a paralell in the vise, and verified it was paralell to the indicator over two planes.
I then selected 12 different keepers (four each from pre 1980, 1980 ish (first year of sintered retainers) and 1995. These were lightlty cleaned with very fine emery, then scotcbrite to remove any burrs.

To the mill, and setting them each on the top of the paralell, and using a .030 height reference (total swing of my bestest was .040"), I ran the table along until the full .030 was seen, then back to verify return to zero - per the image below.
I actually needed to put some blocks of steel either side of it to stop it sliding, but got very repeatable results over all the samples.

I started drawing it up in cad, both as a min, average, and max, but then realised a schoolboy error - that i didn't have my indicator pointer at 90deg, so went back (luckily it was all still set up) and instead of repeating everything, verified the heigh against two feeler gauges, and sure enough, I was only seeing 29 thou instead of the indicated 30.... No matter, so I just drew them up using the same DRO axial readout, but made them for 29 thou.

The end result (these are included angles - just as with the retainers above), was 21.956 average, with a max angle of 22.47 and min angle of 21.67. none of the locks seemed any different from the next over the different years either, which is good to know.

The one big takeaway here, is that the lock / retainer intraction (given the info here and the post above) clearly function with angles of greater tolerance mis-match, than many of us would have expected - at least in stock applications....
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Not surprising that there would be some variation. Clearly if it was an exact match the parts would lock up more tightly but given existing machining tolerances absolute perfection is often impossible and we have to accept "good enough".

Nice work anyway.

Jim

I just stopped by the shop today; they are finishing off a large thread cutting job on the lathe tomorrow morning and I should hopefully be able to knock these out Wednesday afternoon.

Sounds great.

Jim

Well, we are ready to move!
17 modified retainers headed to Jim today. I have two sets (and a couple spares) for my own engines as well.

These are a thing of beauty for sure!

Just in the retainer, they are a 10g saving over the pre 1980 Rover steel retainers, 11g saving over the Comp 712.
And that's not including the reduced mass of the top few coils of the spring either....

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Dave, Good work. Looks like it moved up a little on the valve too.

Yeah, it was always going to, as the original dia at the bottom was fixed, and larger than the dia of the Rover version. Top of the spring is approx .17" below the top of the valve (need to confirm) and was machined reference to this face - they certainly appeared to be very consistent; I checked each one against a valve and retainers as they came off the lathe.
So we will still need to dig-out the spring pockets a little, but less than using any other retainers...

Very nice!

Can't wait to get those, and just in time too. I have an appointment in WV on Monday so a trip to drop those off with Dustin will be in order and I may even be able to put the 340 back together by summertime. Haven't given a lot of thought to how I might rework that engine's blower mount to be a lower height but  it raises possibilities.

Jim

Well, got the heads built up.
I settled on 1.720" installed height. Got all within a few thou and managed to get one wrong that ended up at 1.725, but that's probably just fine....

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Pretty happy with how this turned out, but wow, I spent a long time in getting there.
This whole exercise in prepping the heads for more lift, including shortening the guides, and then still having to hog out the seat pockets by almost 0.10", then and machining the comp retainers out to 11-deg,, has really made me rethink the best way to go about this exercise for those who may be working on it in the future.

Manley 11502 and 11503 are Buick V6 11/32 stem valves, and 4.725" overall length. The Rover valves are just under 4.60" overall length.
Both the Manley valves would need machining down to reduce the head diameter, but I feel like that is a very easy task, and both have single groove locks, so are pretty easy to make work with catalog retainers, and even allow use of + height locks (such as the TA-Performance TA V1434B+.050); but the extra length of the valve is the real benefit... But the Manley valves do work out at $37 each, so that's $600 at the very least, which is approx double what the DW500 / DW501 valves cost - but then again, you also have the opportunity to put oversize seats in the head, and make the valve whatever size you choose.....

My other realisation is that finding GOOD head folks who still play with 11/32 tooling are becoming fewer. Seems like a 5/16 stem, or even metric, have a lot more reputable folks who would be willing to put nice 5-angle profiles into the heads, so just deciding up-front to go for a different guide ID may be a better option....

Might be. My heads are at the shop to be machined for final assembly using the PAC springs. Might be done in a couple weeks.

One of the advantages of staying close to stock height is not having to shim the rocker pedestals to maintain geometry but the longer stems on the valves in my TA heads did not cause much of an issue fitting under the MGB repop valve covers so clearance doesn't seem to be much of a problem. Just had to trim a small notch in the boss for the oil filler plug to clear the chevy stud type adjusters. To go over .550" lift I'm sure a longer valve is needed though. I agree it took a lot of effort to get here but I sure do appreciate your help. I have that bottle sitting on the shelf, the car's back together and all we have to do is figure out the schedule to make that visit happen.

Jim

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Still need to do the rocker shafts. These will go on the 340. I still need to order the cam and main bearings but it will go back together this summer. I have the options of using the old intercooled blower intake, (too tall) an iron 4bbl intake, making a new blower intake, or using spacers with a 300 intake. I'm leaning towards making another blower intake. Maybe I'll post the old one in the classifieds or something.

Jim

Jim, what installed height, and pressure closed and open did you end up with?

Dustin did the final assembly so I really don't know. He told me he had to cut the pockets .050" deeper and used a .015" steel shim for a seat. Had .600" range of motion so my .550" lift is OK. Had to cut the guides .150". Installed height should be around 1.7" but I'm not taking it back apart to check. He felt the open and closed pressures were appropriate for a solid lifter cam, and from earlier calculations I think probably around 350 open and 150 seated. I think those were about the numbers he was throwing around. Really my only complaint is that instead of ordering the pocket cutter for the LS springs he used one he had and it cut the pockets bigger than they needed to be but they won't dance around enough to contact the seals so I think it'll be fine.

Jim