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View Full Version : Piston to cylinder Clearance?



screaminta
01-29-2008, 04:18 PM
Hey, if you have read my onther post, the crank on my R recently blew up. Today, at work I measured my cylinder bore. I guess it wasn't as trashed as I thought it would be. The top of the cylinder measured a 2.8755" near the exhaust port it was a tad bigger (relieved?) at 2.876", and down near the bottom of the cylinder it was a bit smaller at 2.8745". If I get a new 73mm piston (measures at 72.95 or 2.8720") would that be tooo much piston to cylinder clearance? Its a a total of .004" at the exhaust bridge area and at .0025" at the bottom, and .003" at the top. Do you guys think this is too much? I heard that with a forged wiseco you need a little more clearance because of thermal expansion? Also, I used a three point type mic because that is all we had so I do not know whether or not it is out of round... I really don't want to go to the 73.5mm bore because that would put me on the last bore before I would need a resleeve!!! Thanks....

C-LEIGH RACING
01-29-2008, 06:56 PM
Those measurements are ok, I would put a 73 mm right back in there & save the last bore for later.
Neil