I know the guy I bought it from did some engine work? It has a cool head etc.. But I thought that he did the different bottom end with a different top end thing. Is there any way to tell what cylinder I have on it? I need to do a top end rebuild and need to figure out what piston to get..? Thanks for the help!

 

Piston size is going to be determined by bore size. When you get the cylinder honed or bored the piston should be fitted accordingly, depending on the final size of the bore.

 

I understand that. And when I pull the top end I will be able to tell from the old piston what bore etc... My only problem was is that I see when you buy a piston its asks what year? I wasn't sure if it mattered on the top end or not? I know the bottom end is different over years but wasn't sure if that was all? Thanks for the help!

 

When you clean off the top of the piston there will be a number there telling which piston it is. You can also tell by loosking at the piston. The 6 and 7 on the intake or exhaust side will be cut in a half moon shape. The 8 and 9 will be straight across. This was done because of the bridged and unbridge cyclinder. But go with number on top of the piston.

 

Only the 85/86 pistons are shaped like that. Th 87-89 has the boost ported piston and intake bridges on the cylinder.
ERIC

 

the 86' cylinder doesn't have the divider in the intake port, the 87'- 89' cylinders do.[img]i/expressions/face-icon-small-cool.gif[/img]