There are smaller pistons. 760cc
JE 62mm
https://dynoman.net/engine/pistons/custom.htmlBut flat stock pistons, not much cam to use. Hotter cam with more duration has more overlap which is when in snd ex valves are open simultaniously letting the (dynamic) compression out thru the window, more overlap needs more CR by pistons that often are CR 10.5:1. Next common step is 12.5:1.
I made tests with a rather hot cam DP315 (RC315), its recommended valve lash is 2- 3 times more than other hot cams
I measured compression and saw the lower compression with less lash which increased the overlap but lift too. So it became a hotter cam.
Bike felt weaker on the road with less compression but higher lift and more duration.
My pistons are around CR10.5:1 thicker gaskets lower that number a little.
Cam was hotter but gave less power. Maybe pistons CR >12.5:1 should have matched it. These are normal for racers
Possible to order higher CR or after a mold of your head's chambers.
Thats why a cam with not that much overlap is good for a street bike. 125-65/75 designed for higher CR. >10 something
The hotter cams (race) start to give power from 6500-7000 rpm, often very sudden.
More convenient if it happen 2000 rpm earlier.
It is a pity to not use real pistons and cam for your fine head.
Here my cam tests I made soon 2 years ago. Tested 3 different cams within one week.
Ended up with an RC295 cam as my final choice. Still available as DP295 from Dynoman. Cam lift In almost 10mm.
The Megacycle cam might drop into my other engine build, 900cc.
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