hawkls7

i have broken my crank and now wondering why? has any body else had this problem, what should i do to solve my issue, pics below.

Jordan_NationalSpeed

What was your torque and horsepower on the setup? That's insane.

hawkls7

my rear wheel hp was 1100

Jordan_NationalSpeed

Hmmm, that seems really low for a Dragon Slayer to fail.

OUTLAWZ RACING

iTrader: (9)

Better question, what belt drive u have on there? Also it dosent look like it was heated from bering friction either. Im not 100% sure but too much belt tension may have caused it, also what type of transmission?

Shawn @ VA Speed

iTrader: (3)

seen a couple of the callies fail in this area on sc applications-i would run the lunati pro series,i like their forging a little better.

98Z28CobraKiller

iTrader: (17)

What did Callies say? Looks pretty thin where it broke and the bearings shown all look decent. I'd try to see if they will do something about it. For what those things cost, I'd hope so unless there is other damage not pictured.

hawkls7

belt drive is 50mm gilmer. berings looked fine , transmision is 4l80e with yank 3400 stall

CarsandWomen

iTrader: (19)

how was the tune? nitrous? its very odd to see such a clean snap like that on a high quality crank. at 1100hp youll have super high quality rods and pistons, which leads me to believe this is possible: you had a very early detonation in one cylinder, the rod and piston held up cuz theyre awesome like that. that one piston fired so early it rotated the crank backwards vs the other 7, pow pow chicken.

89LS1RS

iTrader: (1)

but look at where it broke. its the end, there was no other rod to push the wrong way.

Jontall

I've never seen this happen before... That's not good and I'd have Callies on the phone seeking answers. I always thought Callies made a good product.

jdpepper

I know some of the guys around here that run the traditional sbc supercharged cars order their cranks w/ BBC snouts. I don't know if that is common practice w/ the ls engines tho....

LS1RedZ

iTrader: (19)

Wow. Thats pretty insane! Some have used stock cranks on here to that hp level.

CarsandWomen

iTrader: (19)

good point


OP what are the details of the situation surrounding the failure? it doesnt look beat up like the rpms wound down after the break either

stevieturbo

Front pulley out of balance or something ?

Jimmy P

iTrader: (177)

But I am sure those weren't supercharged cars with gilmore belt setups...

atomicfusion

I ran the Callies Compstar up to 1132rwhp and never had it fail... This year on my rebuild we went to the Magnum, but that is only because we are pushing up to 1500ish on the RWHP number.

I've always had good luck with callies...

93formto98T/A

iTrader: (28)

Hold on! Now you're comparing apples to oranges. You can in no way compare the stressed of a turbo car (your car) to a SC car. The torque that is placed on the crank snout with a big cog drive blower CAN twist cranks in two whereas as turbo car does not have this added counter-torque. As Shawn@VA Speed mentioned, this is not freak occurence. Big cog drive blowers on LSx motors pushing BIG power is a relatively new frontier and apparently things aren't quite up to par with say the SBC crank with BBC snout...there's obviously a reason for that. I'm regearing my F2 cog with my new setup aiming for 1500rw and Shawn's putting in a Lunati Pro Series crank...hopefully I won't see this issue.

Shawn @ VA Speed

iTrader: (3)

There is nothing wrong with the Callies crankshaft-it is a very capable forging that i have pushed to 2000hp in an ls engine.The stress that the supercharger puts on the crank is much different and the normal stresses a crankshaft sees,the is the reasons for such things as crankshaft supports.The placement of the belt also makes a huge difference-the further forward of the engine,the worse it is.The Lunati forging seems to have a little more material in the overlap area,which should help greatly.

hawkls7

there is not enough material in the overlap as you say, is it safer to not have the lightning hole drilled, keep it solid . I have searched every where for crankshaft supports but i dont seem to see any for the ls engines.I dont want it to happen again, i think i got off lightly this time.