340 upgrade

[castlesid]

Jim,

Happy new year to you all, I have been dropping in to watch progress on your 340 build as well as the BADASS project.

That 340 is going to be a great engine, what sort of power and torque do you think it will make?

Wish I had access to someone like Dale over here, any of our so called specialists want fortunes to do work, aboy double what you guys have to pay for parts and labour.

My new 4.35 engine with modified big valve Buick 300 heads, Chevy rods  Keith Black pistons and Crower 50232 cam, although built  a few months has only recently been installed, and we are hoping to fire it up this coming Saturday, so a little nervous as can be expected with the prospect of having to get the rings bedded in asap and the cam broken in to spec, theres always a bit of conflict with that as you need to get the engine under load asap to avoid glazing the bores,

I have had a few health issues over the last few month which led to the delay but hoping that getting the GT back on the road will bring a smile (or stupid grin) back to my face.

I regularly use a forum in the UK which is great for Rover Buick and Chevy V8 tech issues,

http://www.v8forum.co.uk/forum/index.php?sid=df7988faa6ab21594a588ef5850a8f17

We are having a forum meet at Santa Pod the leading UK drag strip in July this year and I intend running my car to see what it will do!

One of our guys has aan original MGBV8 but now fitted with a near standard Rover 4.6 engine and with a 150 shot of nitrous runs consistent 11.5 second quaters on slicks which is pretty amazing, wouldn't think I will do much better than around 13.5 but it should be a great day out.

Another of our guys is currently building a Buick 455 with alloy heads which is going into a Range Rover which should be a fairly rapid beast, even with the weight of the Range Rover, he is doing some chassis strengthening!

Anyway as I said have a great new year and good progress with youw and the BADASS car, I will be watching for updated as usual and look forward to the days you have the BADASS up and running.

Regards,

Kevin Jackson.

[BlownMGB-V8]

You pretty well nailed it Carl, though the corollary takes most of the sting out.

Thanks for the good wishes Kevin, I sure appreciate the support. Here's hoping everything goes smoothly with your new engine. That should be an excellent combination.

It's always a good idea if possible to change one thing and see the result before changing more. I've gotten pretty far from that this time around and it's likely the car will have a rather different character when it goes back together. If I've done my job well enough though the results should be something I'm happy with. But you know what? I've never driven an MGB with IRS, or even ridden in one. I have driven an MGB with an automatic transmission (Steve's) but didn't drive it hard. The power level will be higher than the last engine but the torque band will be broader as well and off-idle should be very good, so hopefully it will all work out.

I've been giving a little thought to using a Gilmer type blower drive on this engine because the rubber dust on the hood indicated that the 6 rib serpentine belt was slipping a little on the other engine. There are several different tooth profiles being used, some of which are very good and reasonably quiet. Of course I could go to a 7 rib belt right away if I can find one, or an 8 rib if I change the lower pulley and can find the right belt. I'll have to make a decision about whether to use the drive nose off the old blower. There may be some chance that I could sell the complete blower package from the intake up, including the front brace, intercooler, and pulleys and if so no doubt I could get more out of it that way, but maybe I should just clean it up and put it on the coffee table instead. (he he he! Wonder if Edith would go along with that?) Anyone want a blower?

Today is National Hangover Day and it's under 20 outside. So although I'm not hung over I'm in no rush to get moving either. I will try to get out to the lab and do something but not for awhile yet. Pistons and rods are next and I need a reasonable facsimile of an old round oil can to set the piston/rod assembly in oil before installing them. Seems half my days are spent looking for things. I'm also sort of tempted to make  tapered sleeve to use as a ring compressor. I've never had one of those and I'd like to try it. If I can find something to make one out of that is. Oh well, one step at a time...

Jim

[MGBV8]

Now, Curtis, I'm sure you know that @#$%& is derived from that ol' British plumbing company.

[BlownMGB-V8]

Just to make absolutely certain I get the pistons in right, I did a little studying on piston pin offset. Eventually I found this drawing which makes it all quite clear (for non-race applications).



This is the standard offset direction with the pin moved towards the major thrust face of the cylinder, which is the side that the piston pushes against on the power stroke. (Race engines often use zero or sometimes negative offset.) For standard clockwise rotation this means the short side of the piston goes to the left. I have .040" of offset in my forged Venolia pistons, a small enough amount that they could be installed backwards and might not make much noise when cold, and might not cause much greater wear. But as I have one cylinder wall that is .150" thick on the thrust side it would probably be best to install them conventionally, which will help reduce thrust loading.

Jim

[BlownMGB-V8]

Busy day today but I did get some work done. I have the pistons on the rods. Not like that took much, being floating pins and teflon buttons, but it's one more step. Of course, the rods for the odd cylinders were 180* out from the rods for the even cylinders. Amazingly enough, sometimes even very experienced professional engine builders have been known to get this wrong. Guess we're all subject to brain farts every now and then. So I got out the rings and the first bit of paperwork I see says, "File fit..." and I just shoved it in my pocket and moved on. Guess I'll test fit them tomorrow and see what I've got.

While out on errands Matthew and I stopped and picked up some Mobil-1 gear grease with LS additive already in it, so I went ahead and fitted up the posi with the plates in what I felt would be the strongest configuration. Once bolted up that turned out to be good for about 160 ft/lbs of torque after breakaway, which apparently should be plenty, especially for a light car like the MGB. But I'm going to go ahead and try it that way and hope that with the big tires it will all work out. Worst case, the whole unit should drop out with a half dozen bolts if I have to restack for less torque. Sorry I don't have photos, the battery died on my camera just as I was taking some shots. But I do have one of the other posi which I'll put on ebay, they look about the same.

Jim

[BlownMGB-V8]

A little more progress today on the diff, all bolts loctited and torqued. Then another snag, turns out the power-lok and the true-trac units use different side bearings and I blew up the old bearings pulling them off the 2 series power-lok case. So not only do I not have bearings for the posi, my setup bearings do not fit either. Which means I get to go shopping for new bearings. Again. On the positive side, at least my setup bearings will be new also so I won't have to juggle preload on the final assembly. Man I sure love those positive outcomes! Sometimes it's the only thing that keeps me going.

I also checked my ring end gap on the 340 and came out with .020, .015, and .025" on the top, 2nd and oil rings respectively. Not too bad for a start, and falls right into the range of SAE recommended clearances for this size bore. Using Total Seal's (my ring mfg) recommended specs for blown gas applications I'm .001" tight on the top ring (.0029" loose for N/A street) and .0017" loose on the 2nd. Considering that this engine isn't going to be a full out race engine I think I can live with that, so next I need to check the gap on all the rings for consistency. If that looks good then I'm all set to install the rings, rods and pistons. I've decided to go ahead and finish that part up before installing the o-rings in the decks, which should give me time to find a new set of flush cutting snips that I like the looks of.

I feel cutting the ends of the o-ring wires may be a bit of a challenge. For instance, would it be better to cut the ends just a very small bit long, insert the ends and then work back towards the middle, thereby causing the entire ring to go into compression? Or perhaps start in the middle and when an inch or two from the end put the ends in and then the bulge? Will an angle cut truely be the best, and should it be dressed with a fine file or stone? Well I suppose I'll know the answers to those questions in a few days. Wish me luck..I think I'm going to need it.

Soon I'll be switching off to lathe work, maybe sooner than I had planned. I have a chunk of extra extra heavy wall steel tube just a couple inches long that I planned to use for the base of the die set for enlarging the holes in the copper head gaskets, and of course it's also just the right size to make a tapered ring compressor out of. So I may have to saw it in half and make the ring compressor before I can install the pistons. These new rings are only about .040" thick and they might be just a little tricky to install with my old standby band type compressor. Plus everything I've ever heard about tapered ring compressors indicates that they are just a fantastic item, a true wonder tool, and I think I probably owe it to myself to personally experience such a fantasy. Why not? all it'll take is a little lathe time...

Jim

[MGBV8]

Jim,

Check this link & be sure to click on the thumbnails:

http://www.enginebuildermag.com/Article/5198/manufacturer_tech_tip_installing_wire_orings_in_cylinder_blocks.aspx


Thanks for the pic above. It does a great job of explaining piston pin offset.

[BlownMGB-V8]

Thanks Carl, that was very helpful. I especially liked the detailed instructions given in the picture links, that really helped me understand the process. Matthew and I went out today and hunted for the right snips and plastic hammer. Eventually on our second trip out we ended up at Sears where we found three useful items. First, a 6 oz. soft face hammer #38298 which should be hard enough and light enough to do a good job driving in the wire, second a set of Channelock brand flush cutters #357 which I think I can grind to give a nearly square end to the cut wire, and then a find Matthew came up with which was a bag of slip on plastic boots for pliers which give them non-marking jaws. We also picked up a new fine tooth file. These tools should make it much easier to handle the wire and get everything fitted correctly. Dale recommended cutting the wire ends at an angle, much as you would do in joining two long pieces of hardwood trim. So I think I have the idea now, and the tools, and should probably go ahead with that part of the job.

I test fitted the individual rings in the cylinders and there was very little variation in end gap, about a thousandth or so and I was able to swap a couple of them and get even results all around. I will re-check when installing them on the pistons, and mark the holes they are to go into with a sharpie on the piston crown.

It turns out I had overlooked one set of good used bearings that fit the power-lok posi somehow, so I decided to use them as the set-up bearings. This meant enlarging the bore to a slip fit on the carrier. It turns out that a flapper wheel is really inadequate for this job so it would take a very long time to do that way. Instead I chucked up the bearing in the lathe and used a hand held die grinder with a hard stone to dress it out and the flapper wheel to smooth it, fitting the bearings on the old Jag carrier. When I tried them on the 3 series unit I discovered the journals were egg shaped, one by .002" and the other by .006". Evidently this posi unit had been very badly abused. So now I'm back to square one yet another time. I sent the seller a message, hopefully he can make it good.

Funny, I didn't feel like I got much accomplished today. But in writing it up it looks much more impressive. Wonder why that is? Anyway, I just keep trying to do bite sized jobs and not worry too much about deadlines. I guess it'll get done when it gets done.

Jim

[BlownMGB-V8]

Quite a long hard day today and physically demanding too. But, I was able to do some work on the engine this evening. First some pictures.


Here's the cutters after being modified. I ground them down until the groove between the jaws disappeared and then buffed the surface so that I could get a true flush cut at the wire ends, the object being a flat end.


And here's the result. The Channelock cutters use one edge and an anvil so mating the two is a little less critical than it might be otherwise. Not a bad result but it did weaken the cutting edge substantially.


Here the wires are inserted and ready to be marked and trimmed to final length


And this is what the final joint looks like. It really wasn't bad at all using those cutters, and the little Craftsman hammer was just the right size and weight. I marked the wires, pulled a couple inches back out of the groove, trimmed them, shooting for about .020" extra length, inserted the end and tapped it into place and then worked the bulge into the groove. I found the wire to be very bendable, but still pretty tough when it came to cutting it. I had to be real careful about the way I did that, and I nicked the cutting edge several times in the process. I've got another photo.

[BlownMGB-V8]

Here's how it looked when all done. I'm satisfied with the results, and rather pleased to be able to say that I didn't have to start over on any of them. Not bad for an old shade tree mechanic.

I also broke down the differential again and removed the ring gear, Happily the ebay seller is going to send me a replacement. This is where the corollary comes into play. I'm now on the third go-around with the posi unit, all due to unforeseeable circumstances. Lucky for me I had already counted on doing it twice.

Jim

[BlownMGB-V8]

Yesterday I punched out the bore holes in the copper 215 head gaskets , only to discover that they won't work on the 340 because the top coolant holes are uncovered. (steam holes) Anybody want a set of big bore 215/Rover copper gaskets? O-rings are recommended. Guess I'll list them in the classifieds. So I scrapped out the punch and die set and turned the die into a tapered ring compressor for the 3.800" bore. Then I fitted the head studs and set the heads in place on the block, just checking the fit. Looks pretty good so far. I need to get 2 more studs because TA didn't have the right set so I got the 215 set instead.

Jim

[BlownMGB-V8]

Here's what I'm looking at for a camshaft:
dur@.050     lift: In/Ex          Adv. dur       lobe separation      Mfg: Accelerated Motion
205/217         .427/.448        251/264              112                           14821-20743

I realize the specs are kinda mild, that's part of the plan. I would actually like to have a 116* lobe separation, but this will do if it's the best I can come up with.

 I'm using Pat Kelley's dynamic compression ratio (DCR) calculator:

http://www.empirenet.com/pkelley2/DynamicCR.html

This cam gives a DCR of 8.18 which is well positioned in the range recommended for street engines on 91 octane gas, but of course it doesn't allow for variations in the cam lobe area. That's a spec that is difficult to come by anyway. What I'm thinking about is something with about a 240/265 duration and a little less lift on the intake. Stock lift for the 215 was .383" so I may have some leeway there, depending on the ramp. Those numbers give a DCR of 8.26 which may be a little higher than I want to go with a blower, but they also give a 20.5* overlap which should improve economy and make the boost very effective. I like this a lot better than one manufacturer who recommended a cam with 60* overlap, that closed 72* ABDC and had a DCR of 7-1/4. I understand why he made those recommendations, but he failed to understand the application.

I'm trying to find the specs on the stock cam for comparison. I may be a little low on the duration, but at least I'm getting closer.

Jim

[BlownMGB-V8]

The rods and pistons are now installed. Due to decking the block and a slight rocking of the pistons the crowns stick up .008" above the deck. No big deal, I'll just order .050" thick gaskets and that will give me a comfortable .040"+ in whatever little squish area there is around the chamber. I installed a stock camshaft and checked clearances. It turns out there is .050" clearance between the cam lobes and the crankshaft counterweights, and I have .055" clearance to the rods. The cam has .250" of lobe lift which makes .387" or .400" of valve lift depending on the rocker ratio. In this engine at least, any additional lift in the cam comes from reducing the base circle, something I was not aware of.

I've found an old school cam grinder in N.C. who is willing to work with me to come up with a good grind for this cam. Sounds like he knows his stuff and is willing to give it enough thought to make something good. The company is Camcraft Cams if anyone has heard of them. They seem to do quite a bit of Ford and Corvette special jobs. They're in the process of moving from Maryland right now so it'll be at least a couple weeks before anything happens there. In the meantime I'll probably go ahead and order the head gaskets, that way I can install the heads. They'll probably take a little time too so I'll try to paint the block in the meantime.

The saga continues on the IRS. Dan wasn't able to find me another posi and refunded instead, so I'm back on the hunt. I've found a Jag vendor I may buy one from, at about a 50% increase. While I'm at it I'll get some small parts for the Roadmaster that we have to have.

It will soon be time to turn my attention back to the transmission. I've heard TCI now has an automatic/manual valve body for the 2004r which has no delay in the manual shifting positions. Guess I need to contact them.

Jim

[BlownMGB-V8]

The sample 340 head gasket is in the mail to SCE Gaskets and the new copper head gaskets ordered. Another power-lok posi is on order, this time a used Jag unit, hopefully in a little better condition this time, and I also ordered a half dozen brake rotor shims and a hub nut washer. So the only IRS parts still needed should be the coil over units and I have requested a catalog from QA1. The workshop has been hovering right around the low 30's so not exactly warm working conditions but out of the weather and not exactly frigid either. While I'm waiting on parts I guess I'll try to prep the block for paint and maybe tidy up a bit. Lord knows it needs that. Anyway the good news is that Monday's the first day of spring. Couldn't come soon enough if you ask me!

Jim

[ex-tyke]

Jim,
     Quote:  Anyway the good news is that Monday's the first day of spring

     Vernal Equinox coming early this year?......last time I checked, it was March 20/09.
I guess this cold, snowy Winter is getting to all of us......

[MGBV8]

I think he's counting on good news from Punxsutawney Phil.  

[Dan B]

Lawyer logic is involved, I believe.

[BlownMGB-V8]

Lawyer logic? hmmm.....

Well, OK since you asked. Winter solstice is recognized by many societies as "Midwinter's Day". That means the March equinox would be mid-spring, therefore Feb. 2, being halfway between must be the first day of Spring. And just look, isn't the weather warming up nicely? Better get those cars ready!

I believe I'd mentioned that I ordered another posi unit, this one from Coventry West in Georgia, and at a cost of $350 and $60 shipping. Herein lies the reason for searching out a complete Jag rear suspension unit with the desired gears and posi unit before buying. A few more dollars well spent for the correct parts the first time around can pay off handsomely compared to piecing it together. Now that does mean a flange type driveshaft connection and a u-joint yoke is a bit expensive at perhaps as much as $80 depending on where you get it, but changing the yoke is easy compared to a complete setup of the gears. Likewise, shortened tubular half-shafts and lower control arms from an established custom parts supplier such as Concours West Industries (CWI) can make very good sense compared to making them yourself. Now as best I recall I had the IRS unit for somewhere around $250-300, meaning I just paid for a second one at the same price with enough change for the yoke, provided I found the same sort of a deal. Regardless, the total would easily pay for the desired unit and then some.

I have yet to do any more than pull the cover. They sent the entire differential unit including bottom brackets and brake brackets. These brake brackets are cast aluminum pieces with a one bolt attachment point. Obviously it used a different brake caliper, most likely a floating caliper, and I would very much like to get some more information on those, including what material was used for the body and what configuration of parking brake was used.

A cursory check shows up nothing obviously defective in the unit, but it was a core so was most likely removed due to noise. I will begin inspection and probable disassembly in a few days after I check backlash and the torque capacity of the posi unit. I doubt I can use it as-is but you never know.

As for the engine, head gaskets are on order, the mains are properly torqued and the last two head studs are in place. The pan should go on shortly along with the oversized pickup tube and a windage tray if I can fit one. Then I'll start work on the front cover. In about a week or so Charles at CamcraftCams will be able to recommend a cam grind, and checking my valve springs indicates I should have about 300lbs at .490" lift. I think that should work out well.

Jim

[BlownMGB-V8]

I found out why the Jag diff was a core. The cross pins for the spiders had both broken right across the center hole, so it probably made some very odd and hard to identify noises. It wouldn't have caused imminent destruction or anything like that but would have required a nearly full teardown to find the problem. Easier to replace the whole thing. Which works out good for me as there is very little wear, and I still have the cross pins from the trashed Ford diff. They have no center hole so should be stronger.



I removed the pressed on trigger wheel which I believe drove the speedometer but I'm beginning to have second thoughts about that. It might be useful for cruise control and would hurt nothing to put back in.



A very pleasant surprise was that this unit uses 7/16" ring gear bolts rather than the 3/8" ones used in earlier units, meaning it is fully interchangeable with Dana 44 parts, and I will not have to drill out the bolt holes to fit my 3.54 Dana gears. It also came with a set of very nice 3.54 gears, but I haven't yet removed the pinion flange to see if it is coarse spline like the older Jag units or fine spline like most of the Dana 44 ones. If it is fine spline, I might consider just using the new case as the pinion depth and backlash is already set. I guess pulling that flange is the next step.



Dan will be interested to know that the Olds motor he blew up is now gone, other than a few bits and pieces like the pan and front cover, and of course the induction system and blower. I sold the heads and the short block on ebay and the proceeds are helping to pay for the build on the 340. I might as well sell the blower too, I doubt I will use it on the other Olds 215 I have and I will probably sell the 215 as well. That is, whenever I get the time to disassemble it.

Jim

[Dan B]

Not gonna blow the 340?  What are you going to do with that big hole in the hood?

[BlownMGB-V8]

I have a bigger blower for the 340. It's a M-112 instead  of a M-90. That's close to a 25% increase in displacement but the 340 is almost a 60% increase, so I'd have to spin it faster to get the same amount of boost, which would just be crazy, but I may call Magnuson to see what their engineers recommend. I haven't decided on whether or not to use an intercooler this time, I'm thinking it's going to be completely unnecessary though, with the lower boost levels and the higher static compression. Plus with less boost pressure there will be less heat for the intercooler to remove, so I'm thinking it's just more complication that isn't going to help much.

I'm not sure what I can get for the old blower setup, probably have to sell it with the drive including the crank trigger and front cover. That means I'll have to buy a new drive extension and I don't recall what the cost of that was. More questions to ask. Guess I'll need to start mocking it up as soon as my head gaskets come in. More calls to make.

I'm ready to begin assembly of the differential again. Interestingly enough, Jaguar used the same odd clutch stack in this Power-Lok as I found in the other one, a stack that gives 3 friction surfaces per side. Using a conventional stack gives 5 per side. Torque of the unit before disassembly was 40 ft lbs, possibly at least partially because of the broken cross pins, but I should have around 140. Well, this time for sure. Think I'll get a new set of side bearings too. Probably better start looking around for more stuff to sell....

Jim

[BlownMGB-V8]

Seems the details are very important in differential work. I just slapped the thing together but when I tested the torque of the clutches all it had was 75 ft/lbs. So I opened the case and swapped in the internals for the 2 series unit which had given me 140. When I tested it again I had picked up 15 but not what I had expected. So I broke it down again, cleaned the lube off all the parts and set to with dial calipers, dial indicator and micrometer to find out why, and discovered there are some significant variations in the parts, and not always as expected either. For instance, the newer and less worn plates with the inner spline were about .0015" thicker, but the older plates with the external tabs were .003-.005" thicker. The newer spider gears gave maybe .005" of extra height to the internal assembly, but the older cones that surround the side gears were .020" taller.

The stack-up didn't account for the difference in torque so it was probably in the depth of the bores in the case. That's something I couldn't change so I just reassembled with the thickest parts and this time came up with 120 ft/lbs. That's just about what it should be so I'm happy.

Then I slid on the set-up side bearings with a couple shims under each one (they had each had 3 in the other case) and slipped the unit into the gear case, snugged down the caps lightly and checked the play. Shoved all the way away from the pinion it felt like about .020-.030" backlash and shoved towards it there was none. Good so far. Next I'll add shims on the left until the backlash is in range, add to the right until the fit in the case is snug, and then check the pattern. That will tell me if the pinion is centered properly, and I will probably have to re-shim that and do it all over 2 or 3 times before everything lines up right.

If anyone tells you that there are no shortcuts in axle work, listen to them. It's probably someone who has tried it all and knows. And if you ever wondered why work takes longer than the quoted time, just consider the above. Much of this would be the same whether I was doing it or your friendly neighborhood shop, the only difference being they aren't going to give you a detailed description of just what went on because they don't want to look incompetent. Can't say I blame them one bit, I'm only saying when it takes longer than you expect there are usually some real good reasons for that which have nothing to do with the skills involved. All new parts do help, but even new parts aren't always what you expect them to be.

Jim

[BlownMGB-V8]

Sometimes you just get lucky. Too bad it doesn't happen more often, but I sure do appreciate it when it does.








The contact pattern looks pretty good. Evidently my interpretation of the somewhat ambiguous depth markings on the end of the pinions was on the money, so all that's left is to add a shim for preload and install the new bearings which should be in on Monday. It will be nice to have this part of the job behind me. Once it's buttoned up the hog's head will go back on the upside down MG body section to assemble the other parts and finish up the last few pieces. I should be ordering coil-overs sometime during the week as well. Shouldn't be long before the swap takes place. Then we'll see just how close actual practice comes to theory.

Jim

[BlownMGB-V8]

Here are some new photos of the engine.







Jim

[BlownMGB-V8]

Freeze plugs, oil pump shims and a few other small parts came in today, but I've switched off to the IRS again. On that, I turned down the hub centers and polished one of the drill rods down. If you'll remember those were 5/8 dia x 36" long and will form the heart of the forward extension of the lower control arm pivot. I actually have to polish four of them since the Roadmaster will also be using this arrangement. Happily, about the time I finished the first one I remembered a couple of tricks that should speed up the job on the 3 remaining ones, so hopefully I can get that done tomorrow.

So the hubs are ready to assemble to the uprights, and I have new bearings to install in the lower pivots, which means it's almost time to sort out all those small parts and figure out how they go back together. What fun. Once that is done I can put stuff together and look to see what has to be done to make the remaining parts. Quite a bit left to do, but with warmer weather it'll be easier.

Jim