Originally Posted by CarpsCustoms
so im trying to understand all of this...the new bottom end i ordered has the FM80 rod, so that means im supposed to end up building a 40mm stroke right???
How do i know where to order the correct jug & piston?
I hope the ones i already have are right..
The FM80 crank/rod are the 38mm stroke/long rod of the GT5. The piston should come to the top of the 40mm stroke jug, but wont travel as far down , maybe affecting timing. It would follow logic that the GT5 jug is timed for this crank. But who knows for sure? I don't do porting so Im not well versed on the subject. I posted further back pics of the GT5 engine I have and the ports with the piston at TDC/BDC. Maybe that will help you see what you have.