I DONT WANT THIS TO GO TO AUTOMOTIVE EITHER! I DONT THINK THE PISTON KNOWS IF ITS 2CYC OR 4CYC WHEN IT COMES TO HEAT EXPANSION. I HAVE 30+ YRS OF SB CHEVY RACING ENGINE EXPERIANCE AND WOULD LIKE TO RELATE THE PISTON SHAPE AND SIZE TO OUR DISCUSSION.
SKIRT LENGTH IS 65% OF THE DIA. SO A 1.0 DIA. PISTON SHOULD ONLY BE .650 LONG
NO SKIRT BELOW THE WRISTPIN
PISTONHEAD DIA IS .005 UNDER BORE DIA
SKIRT DIA IS .0018 UNDER BORE DIA
RING END GAP .004 2ND RING & .005 TOP RING
IF YOU CAN PICTURE THAT PISTON IN YOUR MIND ITS ONLY 1/3 THE MASS WE HAVE IN THESE 25CC ENGINES AND WE RUN THESE 350CID 4CYC AT 9000RPM FOR HOURS IN A RACE. CAN ONE OF YOU 2CYC EXPERTS EXPLAIN THESE 2CYC PISTON ARE SO MASSIVE? SOMEONE TLAKED ABOUT LAPPING THE PISTON. DO YOU LAP IT IN THE BORE WITH AN ABBRASSIVE COMPOUND AND JUST MAKE IT SMALLER LIKE PUTTING IT IN A LATHE AND TURNING ITS DIA DOWN? WE CANT DO ANYTHING ABOUT THE HEATED INCOMING AIR REDUCING THE VOLUMETRIC EFFICIENCY BUT PISTON TO BORE INTERFERANCE CAN BE HELPED. HAS ANYONE REMOVED OR REDUCED THE QUARANT BELOW THE PIN OR TURNED DOWN THE HEAD OF THE PISTON? I AHTE TO DO ANY EXPERIMENTING BECAUSE YOU CANT GET A REPLACEMENT PISTON.
LONGWINDED ENOUGH
FARMER TED