1970 cb350k piston ring gap?

[lhemrick]

I see in the manual I have that the max ring gap once installed in the cylinder is .031. Just to be sure before I put it back together what should the min. gap be? The manual I have doesn't give me that figure.

Thanks!

 

[hunter31415]

I know that Wiesco calls for .004mm per inch of bore. So your 64mm bore is about 2.5 inches which would be a .010 ring end gap. If I understand what your manual is saying then the .031 is the service limit. You would want less than that on a fresh rebuild.

 

[AlphaDogChoppers]

So your 64mm bore is about 2.5 inches which would be a .010 ring end gap.

You are correct, although that is a bit on the tight side. 0.012 would be safer. Also, the second compression ring gap should be a couple thou more to prevent ring flutter.