Con rod big end clearance specs?

[DonW]

Hi, I have now removed the con rods from my '92 GS engine. It looks like I'm not the first one (since the factory) to be in here. The con rods have professional looking markings for weight, and one has been shaved a bit. On my scale they weigh exactly the same - 678 grams- but borrowing a better scale this afternoon.

So, now I'm wondering if my lower end con rod bearings might be nearly new. I'm going to pick up some plasti-gage and measure. What I can't find in my Clymers or other stuff, is the tolerances for lower end clearance- anybody know?

Thanks,

Don

[DonW]

May have just found it on Duane's site- seem right?
Con. rod radial clearance 0.023-0.069mm (0.0009-0.0027")

[Kurt in S.A.]

Those are the same numbers given in the Haynes manual.

Kurt in S.A.

[DonW]

Wooo hoooo! Got a cool little scale at Harbor Freight (I think it's for weighing jewelery or drugs) that measure in grains and 1/10 grams. My rods are within 1/10 gram of each other, and my pistons are within 7/10s'. I ground a tad off the piston and it is now with in about 2/10's. Some PO had someone do a heck of a job balancing these things. Even are the same little end and big end on the con rods.

Plus, the "old bearings" read exactly the same as the new bearings. Bless those BMW lower ends!

Putting this thing back together!

Don

[Major Softie]

Yeah, you either got VERY lucky, or (more likely) someone good has already been in there (which, I guess, is pretty lucky too).