"How can an engine have more stroke without increasing the distance from the crank pin center to the center of the crankshaft? I have two engines that have the same crankshaft yet one is supposed to have 1.6mm more stroke"
Ok this CAN be true , if they are talking about effect compression stroke which not the actual crankshaft stroke , but the stroke of the piston after the ports are closed( this term is only used when talking about 2st's)
Stewart