I spun a bearing on my 400 & and was wondering what has to be done to use a 350 crank in the 6.6L? I wouldn't mind making a 377 out of it. Any info would be greatly appreciated. Thanks jimV
If it's an 2 piece rear main seal block, you have to use main bearing spacers or special main bearings to get the crank to work. You can use 5.7 rods and 400 pistons, neutral balanced damper and flywheel/flexplate and you're about there. Of course there's the million little things that need done and checked.
Larry T pretty much has it right. However I'm told the special main bearings are about as scarce as hen's teeth these days, and you just about have to use the spacers. Not sure where to find them nowadays. But at least this gives you a bttt to give you a better chance of someone seeing your post that knows where to find either the special bearings or the spacers.
jegs ---but unless you were running the short rods and are changing to the 5.7 and using the same piston you won't have much compression...
Here's an interesting build Hot Rod did several years back using a 400 block, large journal 327 crank and Ford 300 rods. 412 hp 435 ft lbs torque on 87 octane. Flat, wide torque curve. http://www.aces.edu/~parmega/efi/temp/352_long_rod.pdf
Did just that build on the 377 in this 1, It was an animal. Sure had a lotta pull from 1800 all the way up to 6500 or so.
Kinda splitting hairs but yea -- 400/372/347 and 406/377/352. BTW if the engine above were mine, and I could afford it, I'd call Ohio Crankshaft and order a complete rotating assembly to build a 406 (or bigger) with 6" rods. But that wasn't the original question, so.............................................
I overlooked the mention of 327 crank, just sorta assumed (which gets me in trouble) that it would be a build with 350 crank. That way stock 350 rods and stock 400 pistons work togethjer real well.
I have a dim recollection that the low-budget way to put the 350 crank in a 400 block was to line-bore the mains with the old 400 bearings installed, and then install 350 main bearings right over them, using the 400 shells as spacers. Never did it or saw it done, but read it in one of the old hobby rags.
Ebb, You would actually want to hone and not bore, there isn't that much meat on a main insert. But spacers are readily available from at least a couple of catalog speed shops and one can still find the thick bearings if they look hard enough. With a 377 build you want to check the deck height and a zero deck is ideal unless you are O-Ringing the block and using a shim gasket.
If you're thinking of doing it to save buying a new 400 crank, the special bearings are going to run you more than a new 400 crank.
Spacers are available from Reher and Morrison thats where I got mine. 5.7" rods and pistons for a 377. Works great. Pat
But will it get you there first? About the only reason I know for running a small (er) engine is class rules.
The thick bearings are still easy to get. Throw a 350 crank in it, and a good set of 5.7 or 6" rods and it will rev like a 327 but has 50 extra cubes. If you are buying a new crank, just get a 3.75" stroke 400 crank. The extra torque is worth is compared to a 377.
We used to put in 400 bearings and align bore the block to make the spacers.. have to cut the thrusts off the rear main spacer. Man thats taking me back to the 80's when we did them.
I built one. Do not use the Ford rods go with after market. The money saved in the rods will be more than used up in heavy metal to balance it, the Ford rods are heavy. It was a runner.
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