No. 8 nose bearing clearance

[cpetommy]

I'm in the process of re-building my '87 3.2 motor, I have a question regarding the proper clearance for the no. 8 nose bearing. I measured the crankshaft diameter for the nose bearing and it is 30.98 mm, which according to Wayne's 911 motor rebuild book is within spec. The nose bearing was measured and it too is within spec, at 31.06, which results in a 0.08 mm clearance. Placing the nose bearing on the crankshaft, play between the two can be definitely felt. Will this amount of clearance result in abnormal wear of the bearing and will it make noise when the engine is running? Or should I purchase a new nose bearing? Does the new bearing come undersized thus allowing the end user to hone out or ream the bore to have a good fitting, sliding fit with the crankshaft?

Thanks, any help is greatly appreciated

Tommy

[Henry Schmidt]

Clearance on the number 8 bearing is not very critical.
They will not make noise and the only real concern is oil pressure loss. If in doubt replace it they are fairly cheap.
Your clearance should be ok.
They do make different size bearings but all but stock bearings are dealer only and very expensive.
Most wear on the # 8 bearing is caused by over tightening of the belts.

[cpetommy]

Henry, Thanks for the advice, it sounds like I shouldn't be concern with this since the clearance is within spec and I can save some money.

Thanks Again
Tommy