quote:

Originally posted by 183N:
Broke this Liberty/Scat crank at 163 runs during a 4th round win (opponent broke out). The engine was still running, started vibrating bad around half track so I shut it off. It had tossed the alternator belt and when I got out of the car I grabbed the balancer and could move it around.

Took it apart and the crank came out in 2 pieces! Hurt it on a Sunday had the engine back in the car with a new crank and running on Friday, going 7.40s on Saturday. Luckily there was no other damage.

What brand / model did you use for replacement?

Ended up putting the same crank on it because it was the only one we could get in time. Busy week, engine out and disassembled Monday, crank came Tuesday, brought it to balance shop. Picked it up Weds, assembled bottom end weds, top end thurs. I was top 5 in points and had to get it together. The new crank has about 150 runs on it, so far so good. The crank that broke had been turned .010 so possibly could have had something to do with the failure. I tried the time lapse feature of the GoPro when we installed the engine.

For the new engine we’re building now I bought the crank and rods from Molnar. Gave him the weights and had him balance the crank. Good service and the stuff looks nice.

quote:

Originally posted by SCDIV1:
Other than a cast crank, the only one I ever saw break like that was an Eagle 5140 BB 454...

Engine was still running and flexplate was wobbling.....and had just made a run !!


Block survived.....had it line honed and reused it.....

I think that was the last "budget" item that E.B. bought, since then it's all been top shelf. Lesson learned, obviously.

The crank that failed in the pic of the broken rear of the SHP block was a Eagle 4340. 3.48 stroke with Compstar rods.

The replacement SHP was Compstar crank + rods with 500 runs now and being replaced with a new engine using all the same parts.

I'm considering selling the short block instead of rebuilding and replace with new after switching engines.

cool vid