i bought a b18c block with darton sleeves however i noticed when i put .010" oversized rings in the bore they dont need filling, they already have a .008" end gap. Can this block still be used with standard 81mm pistons or do I have get oversized pistons too

 

Has the block been used after it was sleeved or is it new? I would recommend getting it over bored or at least get it honed/check to make sure the cylinders wall are round. As for the piston/rings, check the specs with the manufactor and see if it falls withing their specs. Not all manufactor are the same.

Adriano

 

I'd suggest measuring the bore - pistons need a certain cleanace, depending on the mfg's recommendation. Chances are its been ovaled out. The .010 rings are not a good idea in a stock bore, as Honda rings are low tension, and that would likely put too much pressure on the cyl walls.

 

I am aware that most piston manufacturers allow .004" piston to wall clearance. I would like to know how much bigger can piston to wall clearances be without causing exesive piston rattle

 

bump

 

Umm none bigger. really.. no more than .004 bigger than the pistons.
If it is bigger, companies like swaintech offer a moly skirt coating that can be applied extra thick to take up some clearance.

 

If the rings are slack with a 81mm piston chances are it could be an 81.5mm bore, .5mm is about 0.0197".

 

Make sure you have the right size rings too.