6 bolt crank walk AGAIN

[flexnuts02]

This is my second race motor (both purchased used)

First the stroker walked and siezed, now the current 2.0L is showing 0.010 of crank runout after clutch issues started. I have read that the wear spec is 0.0098.

So what do people do now, obviously i'll take it down and inspect the block to make sure that there is no sign of crankwalk damage to the BLOCK.
Now, if the block shows clean, should I re-use as much as I can including the block? I'm so sick of this and I know I can build a motor correctly. We have the tools and knowledge to do so as my dad and I run our own shop.

Just wanted to see what the general consensus is on MY particular instance.. as I am scared of the plaguing this could bring me as I havn't done much "engine building" reading on these cars, though I know VERY much about them. My car is fully built by myself minus the new shep trans/head and the "used" built 6 bolt.

PS this block does have about 7,000miles but it's a damn shame if thats all you can get when running 450HP in a forged build.

*Links to any good spec/building tips etc would be outstanding!*
Busy man here!

Thanks,
Tyler

 

[Calan]

this block does have about 7,000miles but it's a damn shame if thats all you can get when running 450HP in a forged build.

It's not...by a long shot. You're doing something wrong I think.

What kind of clutch are you running?

 

[haywire96tsi]

I have a six bolt that had crank walk. I had a fidanza 6 puck . The machine shop told me the crank walk was due to a clutch problem, most likely no clutch play.

 

[Black-Out]

The nature of your clutch problem may be the info we need as before stated to help with pin pointing the cw issue....If the clutch has high clamping force (2200psi or more) and the clutch is mis-adjusted...I think the free play 5/8? someone correct me if I'm wrong.....at any rate if constant pressure is being applied to the flywheel then I could see that sheering enough oil from the thrust bearing at idle (under lower oil pressure conditions) that it could cause cw simply by extending the amount of load the bearing sees during the life of the motor....Course this is my speculation but in any condition where the thrust bearing is laterally loaded constantly it could cause that very issue....course if thats the case the clutch engagement would have been garbage as well with take up being close to the floor and possibly having issues with getting into 1rst gear from a stop at idle.......
What kind of clutch issues where you having? or did the issues with the clutch crop up AFTER the cw issue became a concern?
William-

 

[flexnuts02]

I didn't read everyones reply.

Its a high 2k or low 3k ACT PP with a custom clutchnet clutch which was modified by the owner of clutchnet (heavy spring disk). New shep was installed with new clutch, used PP but it was fine with no cracks or hard burns from my previous useage (newer PP).

It was fine for about 2 months. I am a certified fulltime tech I do everything at work, clutch adj was right off the floor (grabbing) and it DOES have free play. We suspect a master/mechanical clutch issue but the more I cruise it to feel the loss of clutch pedal height, the more I imagine the crank shifting being the problem.

I spec'd it with a new dial indicator and got 0.010 movement. The max wear spec is around 0.0098 so I'm JUST out of spec. I'll inspect the mechanical clutch parts but I can't see any way around a new block with my OWM proper tolerances for the first time.

Right?

I'm replacing the master with a part form beck arnley since I can return it, just to see if that changes anything, but regardless the crankshaft runout is now outa spec and I'd love to save anything I can on the current engine.

Tyler

 

[SOADweskey]

Well if it makes you feel any better I had my 7-bolt measured at 0.011" of play and when I pulled the motor after another 60k miles of hard driving it was still working fine. I just pulled it because I finally finished my 2.3.

 

[Black-Out]

well aside from that it sounds like you have a great grasp of everything you've done so far so I'll ask you the next important question which is what weight oil your using and whats the oil pressure at idle when the engine is at full temp?
The reason I ask is because if your readings are low you wont have much shielding on the thrust bearing...the only other thing I can logically suggest is that when you arrive at a stop DO NOT LEAVE YOUR FOOT ON THE CLUTCH with that much pressure plate spring pressure.....This is the only other thing I can think of that can cause the shearing of the oil away from the thrust bearing while the engine is running........
William-

 

[flexnuts02]

I never hold the pedal down in any vehicle as I naturally feel that they will "bleed off" and grab .

I run 15w-50 by mobil one, at full temp after a pull she reads about 15psi at 1k RPM. The "stock" spec is 11.5psi at idle.