Broke crank

[gteatr6]

I guess I'm lucky she stayed together and didn't window the block.

 

[Eticket]

nice win.... how fast is/was the car?

 

[Boost231]

Lucky..

 

[gteatr6]

nice win.... how fast is/was the car?

Not sure, I was going to the track the next day

From past experience, I'm guessing low 11's.

 

[rag231]

Now you have a great reason to get a forged crank. To stroke on not to stroke that is the question. Sorry to hear about your bad news but we know the weak links of these cars when we push them hard.

 

[gteatr6]

Now you have a great reason to get a forged crank. To stroke on not to stroke that is the question. Sorry to hear about your bad news but we know the weak links of these cars when we push them hard.

I'm putting a production 4.1 in now. Bad thing is it has a stock crank and caps too.

 

[Eticket]

Lots of factors contribute to this, I have billet caps, but the times in my signature with the current car are with a stock crank.

 

[rag231]

Same here, one motor with stock crank and billet caps, but I know if something else happens to this motor , new forged , billet and roller internals for sure.

 

[gsgnnut]

 

[DarthBuick]

I am guessing the cap broke and the flex snapped the crank? How many miles on it and was it detonating or anything. I am just curious.

 

[gteatr6]

I think the cap broke first too. I am running e85 and 25lbs of boost. I don't think it was detonating, but its possible. I simply could of got a bad batch of e85. Head gaskets were perfect and I've been running this tune for about a year. The thrust bearing was spun and the trans always did seem to shift late, this time it never hit 3rd till I lifted. Of course that was to late. A number of different things or a combo of them could of caused this. Just would be kind of cool to narrow it down.

 

[GBGN1]

Great save, I agree with cap . But what would make that cap crack? Possible crank flex? Or pre detonation at those cylinders? With the advent of billet caps and cheap forged cranks I believe there's no reason to run a stock crank anymore. These cranks are almost 30 years old.

 

[turbodave231]

That block is likely cracked too. I've seen it before on blocks that didn't break the crank. Only magnaflux will tell for sure.

I'll bet the cap broke first from crank flex/detonation and the lack of support finished the crank.

 

[Chuck Leeper]

A good explanation of why the guy that invented the engine hoist, later designed the Buick V sicks.



He wasn't selling enough hoists.

 

[MCH86GN]

I guess I'm lucky she stayed together and didn't window the block.

That what my crank and main caps looked like when my engine detonated. I think my crank was in a few more pieces than that though and my block was ruined. Both center main caps broke and two pistons shattered. Surprisingly, my cometic head gaskets and ARP studs, kept the head gasket from blowing and there was no damage to the heads.