Maybe a bit stupid question. Piston to bore clearance? Measured from one side or both sides at the same time? Always confusing. I'm giving my barrel to rebore this week and need to know what to tell to them.

Thanks
Kalle

email (option): kalle.tikas@gmail.com

For our old English single cylinder motorcycles it usually 0.10 mm.

Henk

email (option): ahum@quicknet.nl

A 0.05" clearance means a good tight fit of that size feeler up the front or back. The piston would be hard against the cylinder wall the other side.
http://pub37.bravenet.com/forum/static/show.php?usernum=3155626639&frmid=16&msgid=1125520&cmd=show

Shouldn't that be 0.005" Fred? You can run them as tight as 0.0035" but it usually has to be an old stock piston or a Hepolite.

email (option): davmax@ntlworld.com

Oh yes, thanks, hopefully it doesn't really matter what i put as its meant in the context of a hypothetical example,
I was posting really to pass on that link to Ian's post which has the clearances written correctly.
Still think its a shame we only get 1hr to edit mistakes.

Kalle. Your machine shop will probably know anyway. You have to make the cylinder bore bigger in diameter than the widest part of the piston skirt. In English terms that is 0.0045"-0.005" (4.5-5 thousandths of an inch).

Ron

email (option): ronpier@talk21.com

Thanks. We understand more metric scale here so do you think 0.12mm (0.0047") is good for NOS piston 66-1025 (with piled arms logo on top of it). Not too tight I believe.

Kalle

email (option): kalle.tikas@gmail.com

Hi Kalle.. That will be perfect...Ian

email (option): ian@wright52.plus.com