10 under crank reliability

[GBGN1]

Ive located a BA steel 3.625 crank.Mains are standard ,rods are 10 under.Any reason reason to worry about that?Im thinken it will take the abuse but wanted a second opinion.Thanks:wink:

 

[jasjamz]

No big deal.

 

[Squid4life]

How much power you planning on making and with how much boost. I don't think .010 under is that big a deal.

 

[GBGN1]

Building for around 650-700 at flywheel.I think it will be ok to.Just wanted another opinion .thanks!!!

 

[buickboy]

Should be good. Tune it, Tune it, Tune it.
Mitch

 

[Grumpy]

we have used a 20/20 STOCK crank with no problems for 20k anyway.. ran 9s@ 138+

 

[turbofabricator]

I agree with Grumpy. I never understand why people think that a 20/20 crank is weaker? The rolled fillets are usually deeper than .020 (usually .050"+) The weak link in a Buick crank is the rod cross-over not the actual thickness of the journal. .020" is still only .010" on each side. If any of you want to dispose of your .010/.010 turbo cranks because they are weak, send them my way. I'l use them in everything but a 700+HP engine, but that's only because the forged cranks are cheap enough to use for that power level.

 

[boostingbuick]

I ran a stock crank 20/20 deep in the tens, and few years later broke a standard crank. Detonation will break things faster than taking .020 worth of metal off. Like above, the tune is the key to a good engine life.

 

[gnx7]

The amount of material they are removing is something like the thickness of a human hair..... Run it!

 

[bison]

I'd run the .010 under ba crank to 1000hp and not be concerned at all. I'd be more concerned about the block/rods used and the tune

 

[Nick Micale]

Ive located a BA steel 3.625 crank.Mains are standard ,rods are 10 under.Any reason reason to worry about that?Im thinken it will take the abuse but wanted a second opinion.Thanks:wink:

Without knowing what "abuse" the crank was subjected to for it to be turned, and your plan is use [race , street,?], it is difficult for me to base an opinion for yes or no?

I have had a 0.010" under forged crank break during break in, seen others break at idle and some a high RPM, and have seen stock cranks destroyed in an engine on a 13 sec. pass.

Also have seen 10 under cranks run for seasons with no problem.

Very simply, my opinion if I was spending close to $10K on a new engine, I would not settle for anything less than a new "heart"! :biggrin:

 

[87GN_70GS]

The rolled fillets are usually deeper than .020 (usually .050"+)

I measured mine at .025" under. So a crank could be turned only twice (to 0.020") and still retain the fillets.