346 Flathead crankshaft

[wicho46]

Hello fellow members.  Looks like my crankshaft connecting rod bearings failed. So im looking for a replacement crankshaft.
My Question is. I see there are two different harmonic balancers available, are these interchangable? Question#2 is there a difference between a manual/auto transmission crankshaft flywheel mount hardware?
My current crankshaft has the big heavy harmonic balancer and 3speed tranny hook up. Would the other crankshaft with the smaller harmonic balancer work with my same front engine timming chain cover?
Trying to keep the old flathead cadillac engine running.
Bearing failure due to a pluged up intake screen on oil pump.
Thank You
L Lopez

[Steve Passmore]

Why are you looking for another crank? is yours not recoverable? they can be ground to 60.  Lack of oil to the engine in general would cause damage to many other surfaces also, best to give the motor a good inspection before laying out for a crank.
You don't say what year it is but as far as I know the timing cover is the same from 37 on so the balancer should interchange but there are differences between the early cranks and the later ones, There's no difference in the rear of the crank for auto or manual,

[markl]

Mr. Lopez,

Don't know where you are located, but if in the USA, almost every major city has a crank grinder.  And most crank grinders have a process called " Submerged Arc" welding which allows them to build up a crank journal.  So if only one or two journals are damaged, you might inquire about this process and then only grind the crank a minimal amount.  I agree w/ what Steve mentioned about the effects of oil starvation.  But getting the crank re-hab'd should be easy.

Mark Lowery, CLC #25216

[Paul Phillips]

I would agree that you should be able to re machine your existing crank. When i rebuilt my 346 it had an impending bearing failure on one main and was able to clean it up by going 020 under on the journals.  One other think to look for is a machine shop who can either grind the journals with the counterweights in place, or is comfortable taking them off and sourcing replacements for the mounting screws.  i never found a source for new factory screws, but did find grade 8 socket head screws that were slightly longer threads, which could be machined shorter. I also found there was a fair amount of wear on the cam lobes, so you may want to check that while you have things apart.

Good luck!
Paul