Max valve size for 4.0/4.6 heads?

[Airwreckc]

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

[MGBV8]

Great info Dave!

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

[BlownMGB-V8]

>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

[MGBV8]

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

May be a good reason to go with larger valves.  

[BlownMGB-V8]

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

[turbodave]

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....

[BlownMGB-V8]

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

[mgb260]

Jim, Alex's Parts.

[BlownMGB-V8]

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

[roverman]

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.

[mgb260]

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?

[minorv8]

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

[BlownMGB-V8]

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

[MGBV8]

From Jukka. in 2018:

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

[mgb260]

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.

[BlownMGB-V8]

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

[mgb260]

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

[BlownMGB-V8]

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

[mgb260]

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

[mgb260]

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.

[BlownMGB-V8]

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

[mgb260]

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.

[BlownMGB-V8]

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

[mgb260]

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?

[BlownMGB-V8]

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

Jim