Has anyone snapped a stock crankshaft?

[99Xtreme_lover]

I have done 225 shot on stock crank but with an 2 stage and made more then 400 rwhp . You have lots of good parts ( block and heads ) why would you like to risk all that with an cast crank ? This is just my opinion . On an turbo motor it should be fine but the nitrous is twice more hard on the motor then turbo . I now have an new bowtie block and oddfire forged crank and i'm thinking on turbo but i love the juice so maybe i go with even more nitrous . Again this is just my opinion

 

[Syborg Twin Turbo]

I agree - the stock crank scare the sh..t out of me. I bought a billet crank from Mike Lee (most expensive part of the motor). I don't want it to come apart because of a week link. My best friend blew a billet crank out of the bottom of his mowtown block with the caps still attached to it and the crank was still good. everything else was junk but the crank looked nice on the track.

play it safe and pick up a crank from Mike i think he has 2 or 3 left.

btw - years ago when i used to talk to PAS the told me the replaced alot of motors because of piston and crankshaft failure.

 

[nightdiver]

He has one less now 8)

 

[rarebit]

I've snapped 2 stock cranks in 2 years. 2 bolt main, eagle rods, trw pistons. No knock. I attribute some of the failure to the t72 turbo pushing 20psi+ and a lead foot, but I could be wrong. From what I understand, the failure is vibration related. Both times the crank broke between #3 and #4 rod journals. Everyting else intact. The crank I have now has lasted 2 years. I'm now running 14-16psi.

 

[jwaller]

are you guys that push them hard internal or external balance.

external balance causes much more harmonic vibration and is hard on the crank.

internal solves those issues and has a lower interia moment and makes for a quicker reving engine.

 

[bezerk]

This is the problem my new Ty has, (No! i didn't do that)

 

[myclone]

This is the problem my new Ty has, (No! i didn't do that)

Hmmm.. Looks to me like that engine has been into before due to the "polished" beams on the rods and balance holes drilled in the bottom of the piston at the wrist pin.

If thats the case then Id check stuff out pretty close to make sure the machine work was done correctly. That might save you from the grief of another broken crank if the line bore is off or something similar.

 

[bezerk]

Yeah, that was my geuss also, the polished rods, i have never seen those before.
Annyway, i bought it without the engine, why should i, already have 3 of those