? Reduction in C.R with short stroke crank
 

If I used 10.7:1 C.R pistons in a euro 3.0 carrera case, but used a 66mm crank instead of a 70.4mm crank what would the C.R drop to?

Robert

this type of compression reduction is not very nice because you lose a lot of squish. If you don't have the pistons already, I would get pistons that were made for the stroke you are using.

I don't have Bruce Anderson's book handy with me, but if I remember correctly he said you get about a 1 point compression increase when using 70.4mm crank in place of the 66mm. Bruce Wayne's book states that if the 70.4mm crank is used in place of the 66mm compression is raised to about 10:1 (stock is 9.1:1 w/E pistons). From this I'd guess about a drop of .9 to 9.6:1. This would probably be good if you don't plan on twin plugging and want to run on pump gas, but you will have the obvious drop in power.