MG Sports Cars

engine swaps and other performance upgrades, plus "factory" and Costello V8s

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BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: December 08, 2008 05:05PM

Things are looking up. I have some photos of the engine parts for you and everything looks real nice. I have to hand it to Dale, (Motion Machine in Danville, VA) he does excellent work. Extremely good at communication as well and a real pleasure to work with.

MVC-881S.JPG

MVC-887S.JPG

MVC-883S.JPG

MVC-886S.JPG

As you can see the reciprocating assembly is pretty light so with the long rods this engine should like to wind up. I may have to consider an aftermarket torque converter to keep the rotating weight down. No need to worry about that for awhile yet though. The piston crowns are also reasonably thick for blower use. These are Venolia pieces. Apparently I took 6 grams off the rods in relieving them for cam clearance. Dale said they were within 2 tenths right out of the box, a rarity in his opinion. Seems my whittling didn't throw off the balance much at all. So if you want to build this motor it might be a good idea to use the same supplier for the rods, especially since it was a good price. Looks like I might need to run out and buy a few more cans of brake cleaner and get started.

Jim


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: December 22, 2008 01:40PM

More good news! I've ordered the head studs, crank seals, oil pump pick-up and wear plate, and if they managed to ship them Friday before shutting down for the holidays I may be able to begin assembly in a few days. The engine bore brushes are laid out in preparation and I'm all set to go.

Meanwhile, the ebay Power-Lok came in, was disassembled and cleaned. The clutches were trashed (one bevel washer broken) but the gears and case are undamaged so the plan is to just use the case with the internals from the Jag unit. However, torque testing showed the Jag unit could only produce 80 ft/lbs of torque between axle shaft and case and the one recommended spec I've seen for that was 140 ft/lbs. So I'll be looking at what I can do to bump that up. One recommendation was to reverse the bevel washer. I'm not sure how that would help though. Another thing is that the Jag has a rather odd stack of the clutches, which it seems could be easily improved on, where the Ford unit had a very straightforward alternating stack.. I may have to buy more clutches. Another curious difference was the way the side gears are made. On the Jag the cone the gear sits in has a spline that matches the inner clutch teeth, but the Ford does it by essentially cutting the gear hub off short, in essence splining the cup to the axle shaft instead of to the gear. It doesn't look as strong to me, but since I'm going to use the Jag internals it really doesn't matter, unless I run into space problems with the clutches.

It's supposed to get up to 50 in the next couple of days so I'll probably get a chance to see what I can do with the parts and maybe post some photos. The only shot I have right now is of the bad clutches in the ford unit but I can post them, as a shot of what you get if the axle can only generate maybe 10-20 ft/lbs of torque.

Jim
posi clutches.jpg


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: December 30, 2008 07:07PM

I started assembly today after having done a good cleanup yesterday, and I have a couple of photos:

MVC-014S.JPG

MVC-015S.JPG

This engine is a first for me in several ways. First iron block SBB, first o-ringed deck, first engine equipped with studs on mains and heads, custom forged pistons and aftermarket rods, and in a few lesser ways as well. But if I've learned anything by this point, it's that attention to the smallest details can make or break an engine build. With that in mind I'm going to do my best to not overlook anything, so I'm taking my time with it and giving a lot of thought to each step.

I'd considered securing the studs into the block with loctite. On reflection I realized this would make removal of the main caps pretty difficult and so I went with the moly lube instead and installed the studs in accordance with the ARP instructions. They only addressed lubrication of the threads but if you think about it the washers need to be lubricated too for the most consistent results. Checking of the bearings and journals showed that Dale had pretty well nailed the .002" main clearance we had decided on, so the bearing shells were coated with assembly lube and the crank installed. The center main cap lines up well if it is tapped to the rear before final torquing, and the rear seal halves lined up well without any other work. The crank rotates easily and has .004" of endplay, which should be OK. I used TA's two piece neoprene rear main seal, which requires the seal groove in the block and cap to be dimpled with a center punch for spin resistance. The seal is inserted with about 1/4" protruding out one side so that the split is not at the cap split and a sealant (Right Stuff) helps seal it and anchor it in place. Not a lot is needed.

One place a lot of people mess up is by not sealing the cap split. There are a pair of side seals to seal the cap to the block, but the split line can be a source of leakage if some sealant is not smeared between the end of the seal and the side seal.

That pretty well concludes installation of the crank, of course cleanliness is everything. Next will be preparation and install of the pistons and rods, at which point I can button up the bottom end.

Jim


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: December 31, 2008 03:35PM

If the first rule of engine building is clean, clean, clean, then Blackwood's Corollary is that "If it's worth doing, it's worth doing twice." Anyone, no matter how many times they've built engines can make a mistake or overlook something. I somehow overlooked cleaning out the oil holes in the crank, so I got to spend some quality time taking it back out and doing it over. On the plus side though, it gave me a real good chance to see just how well my sealing job on the rear main cap went, and I'm very satisfied that all the mating surfaces were properly sealed. This is an area where many people have trouble with oil leaks, but as long as the rear seal does it's job I think I'll have no worries there. I did something a little different, I rubbed a thin layer of moly lube into the seal journal on the crank. It has the diagonal scores which are supposed to help sling oil away from the rope seal but I don't think it will hurt a bit for those grooves to be filled with the moly. I also noted this time that as the steel pins are driven down alongside the side seals the 'right stuff' sealant squishes out the ends of the chamfer at the corner of the cap. If this gap is not filled it creates a direct route to the outside of the block. Many people use RTV here, but RTV is not resistant to oil and will soften over time. I would not, under any circumstances use it inside an engine.

So philosophically I feel it is best to approach any task on a car as if it is going to be done in it's entirety two times instead of one. This helps to avoid frustration when it has to come back apart, and it also overcomes the natural tendency to rush or cut corners. If you already assume it'll have to be done twice, then you know you have enough time to be real particular about it the first time. I'd rather do it once, and most of the time that works. But I'm not going to approach it that way. I've found "Blackwood's Corollary to make for a much more satisfying experience. But of course it raises the question, "If it isn't worth doing twice is it worth doing at all?" All I can say about that is, Maybe.

Jim


MGBV8
Carl Floyd
Kingsport, TN
(3761 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: 340 upgrade
Posted by: MGBV8
Date: December 31, 2008 08:35PM

Quote:
I somehow overlooked cleaning out the oil holes in the crank, so I got to spend some quality time taking it back out and doing it over.

The ol' woke up in the morning and said, "Crap! I knew I forgot something!" :)


castlesid
Kevin Jackson
Sidcup UK
(361 posts)

Registered:
11/18/2007 10:38AM

Main British Car:
1975 MGB GT Rover V8 4.35L

Re: 340 upgrade
Posted by: castlesid
Date: January 01, 2009 08:39AM

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,

[www.v8forum.co.uk]

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
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 01, 2009 11:18AM

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
Carl Floyd
Kingsport, TN
(3761 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: 340 upgrade
Posted by: MGBV8
Date: January 01, 2009 11:38AM

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



Edited 1 time(s). Last edit at 01/01/2009 11:40AM by MGBV8.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 02, 2009 10:50AM

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).

Piston pin offset.JPG

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
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 03, 2009 12:25AM

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
MVC-016S.JPG


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 04, 2009 01:14AM

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
Carl Floyd
Kingsport, TN
(3761 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: 340 upgrade
Posted by: MGBV8
Date: January 04, 2009 09:28AM

Jim,

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

[www.enginebuildermag.com]


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


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 04, 2009 09:06PM

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
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 05, 2009 11:22PM

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.

MVC-023S.JPG
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.

MVC-025S.JPG
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.

MVC-026S.JPG
Here the wires are inserted and ready to be marked and trimmed to final length

MVC-027S.JPG
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
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 05, 2009 11:30PM

MVC-030S.JPG
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
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 09, 2009 11:53AM

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

MVC-037S.JPG

MVC-040S.JPG

MVC-041S.JPG

MVC-042S.JPG


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 22, 2009 12:07AM

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:

[www.empirenet.com]

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
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 26, 2009 03:17PM

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
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5812 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 340 upgrade
Posted by: BlownMGB-V8
Date: January 29, 2009 09:36PM

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
Graham Creswick
Chatham, Ontario, Canada
(1083 posts)

Registered:
10/25/2007 11:17AM

Main British Car:
1976 MGB Ford 302

authors avatar
Re: 340 upgrade
Posted by: ex-tyke
Date: January 29, 2009 10:09PM

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......
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