Bracket Talk
How many runs on Crankshaft

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February 24, 2020, 01:20 PM
green1
How many runs on Crankshaft
Well I guess you know the limits of that crank now.
February 24, 2020, 01:23 PM
Mike Rietow
quote:
Originally posted by green1:
Just for the heck of the discussion, how many people know somebody who broke a new crank compared to how many broke and old crank?
I had a Trick Flow crank that cracked on a main journal and it started eating that bearing and I got it out before it broke. It was only three seasons old.


I had a guy I did 355 sbc for, this thing was a freak for an over the counter bracket engine. Ran 6.50's and low 60's @ 3300 pds on gasoline. He asked me 300 runs in on the engine, if I had ever broken a rear main stud after he had replaced the stud and not pulled the cap to inspect the bearing. I told him the crank was hurt bad. It spit the crank out in the burnout box next pass. I stood there on the fence and shaking my head.

IMO a System One oil filter will warn ya on a hurt crank, the same as getting good a detecting a hurt lifter.

Lifters with excess service, you check the lash more often. Crank you check the filter more often.
February 24, 2020, 01:46 PM
Big Steve
quote:
Originally posted by green1:
Well I guess you know the limits of that crank now.


Yes limits for sure but there were some harmonics that I feel led up to the unknown crack, broke a couple if rockers under power once, had some tune up issues during the learning curve causing it to lay over on multiple runs in the lights which will also cause harmonics. Have a Winberg billet crank now and tune up is under control, hopefully it will last until the recommended 150-200 run swap out
February 24, 2020, 01:56 PM
Mike Rietow
If I were the OP, I'd look at the bearings, they'll tell ya how happy the crank is about its work. If it's not sizzling the bearings out of it and the mag is good, why change it? You might throw out something usable, for a junk replacement. How it all looks is a good indicator of how tired it is.

If you're hell bent on another chinese crank, new. You might wanna pull the trigger asap. There's gonna be shortages looks like Corona Virus has China shut down. And will for be awhile apparently.

Ain't that a shame the shelves at Walmart are gonna get empty... Nope.

I'd do an American crank if there's not enough confidence in this one with 170 miles of wide open throttle on it.
February 24, 2020, 03:32 PM
TD3550
quote:
Originally posted by Big Steve:
quote:
Originally posted by TD3550:
Looks like the rods "Didn't leave the area" either
Great save. How much you throwing in that beast?
40?


30lbs boost, most likely pushing 2500hp on a 2000hp rated crank. It obviously developed a crack then broke. Engine locked up tight, rods stayed in, some minor damage to the #1 main. Did bend all my Ti ext valves which sucked.


Allison fluid holding still ok?
February 24, 2020, 03:43 PM
Big Steve
quote:
Originally posted by TD3550:
quote:
Originally posted by Big Steve:
quote:
Originally posted by TD3550:
Looks like the rods "Didn't leave the area" either
Great save. How much you throwing in that beast?
40?


30lbs boost, most likely pushing 2500hp on a 2000hp rated crank. It obviously developed a crack then broke. Engine locked up tight, rods stayed in, some minor damage to the #1 main. Did bend all my Ti ext valves which sucked.


Allison fluid holding still ok?


Ask me after this weeks D4 race at Belle Rose