Anyone have a crank turned .010 with a lot of hp?

pj91gsx · 09-05-2009, 08:54 PM

Anyone ever broke a crankshaft because it was turned over and too much hp? I was talking to a dsmer that broke a few crankshafts that were turned .10 over and I cant figure out why. He said he had 654 hp. I will be using a ported cylinder head and a 2005 holset hx 45. I think that is the turbo, my brother bought it. As for my research, no one on her has broken a .010 over crankshaft or even a crankshaft that was turned at all. Anyone know why the crank would have broken?

Rob10_99 · 09-05-2009, 08:59 PM

Well the stock crank is nitrite coated, that .010 under size doesn't affect the strength of the crank much at all. Were those broken cranks stroked or ones with an overheated journal from a spun bearing?
Most of the time when someone spins a bearing or has rod knock, they let it go way too long, I assume those cranks your buddy had were bought for cheap for that very reason.

pj91gsx · 09-05-2009, 09:07 PM

thanks for the reply and that is a very good point. I will ask him tomorrow. I know for sure that the crankshaft that I have did not spin a bearing but it was just grooved from people that don't like to change their oil and run their car hard. The 255hp over powering the stock regulator wore that rings out to end the engines life as well. So sad.

Defiant · 09-06-2009, 01:26 AM

Nitriding is not a "coating", but a molecular treatment.

Mitsubishi says their crankshafts are not to be machined. Do what you like.

This topic has been extensively discussed.