Originally Posted by greglewis
Great. So you could use the same piston?
In some circumstances you could but not likely with this engine. With the smaller stroke you need to run the top of piston a little higher at TDC to maintain the same compression ratio. (You are only squishing 450 cc into the space above the piston where you used to squish 650 cc.) That makes it closer to the lower end of the valves when they are open (the end of the exhaust stroke). You need to reshape the top of the piston to prevent contact with the valves and there could also be issues with ring placement depending on the particular engine cylinder/head design. The nice thing then is you have a piston that could be placed in the standard stroke engine that would raise the compression ratio over stock. Cool idea.