Some of you remember a while back we posted this thread:
https://my350z.com/forum/showthread....=oil+pump+fail

Where we broke a stock oil pump in 2 pieces comming off the launch control at 6500RPMs....Well We since have taken the motor apart and found 1 thrust bearing and one main bearing were ruined.Not fully spun, but damaged badly. We sent the crank shaft out to get polished and Magnafluxed, and got the report back today that the crank had several hairline cracks in it.. Bummer..

I guess the VQ crank does not like launch control..I am heading over to our machine shop tommrow to pick it up and will post some pictures, however I doubt it will be visible to the human eye..

Back to the drawing board.

Here is food for thought...We dont know if the actions caused the crack or if the crack was pre-existing on the doner motor we used. The motor we used was out of a BADLY totaled 350z that suffered a MAJOR side impact and broke such things as the CF drive shaft and the Motor mounts..SO in theory, the crank could have suffered some structural damage from the shock of the impact. We didnt Flux the crank in the beginning cause it never came to mind, but the motor did have about 6000, built miles on it prior to this failure.

 

Wow-I'll stay happy with 1.6 60ft's and not put the motor and stress on the turbos using the LC (if that was the cause)

 

Can you get pics of the cracked crank??

 

I'd bet it was from the wreack,and the cracks just got by some how.

 

Which thrust bearing and main bearing was it?

 

THEN to launch at 6500 DAMN!

 

It was the 3rd main from the front of the motor..and respective thrust.

 

launching at 6500 rpm? jeez.

 

Launch at 6k and see what happens

 

I only had my car on the street and I took out a crankshaft... or should I say my UR pulley did?

 

Come to think of it...I had a god darn UR pulley on that motor!!

 

Same one on my motor as well. I didn't have high horsepower but I did do alot high rpm launches and drove alot of miles at 6000+ rpm.

 

You may want to consider an ATI super damper on your next build.....even a stock crank pulley (with dampner) would be better at comtrolling harmonics and vibrations than a UR (undamped) puuley.

 

i feel happ even more now to have gotten the ati harmonic resonater pulley

 

You guys are crazy! Busting a crank!

 

crank that!
http://youtube.com/watch?v=sLGLum5SyKQ

 

I didnt know if you were going to post this or not Julian but I should have known that you post everything and hide nothing from any forum members. If your car blows up you tell the world. My vote is you get a 4.2 but you know that already

 

True, we tell all the world what we break and how, so the rest of the community and our customers may benifiet from our blown motors, and not theirs..Trying new stuff, has meant me having my car down for some time, but once we are back up and running all in the world will be right again. Chances are, if someone has an issue with a motor or something on the Z, we have experienced it in th epast 5 years with either my car or Jason's old car. We like to think of it as "adaptive learning"...

 

props 4 honesty!

 

lawl at lauching at 6k