Measuring squish band and deck height

[rapidray]

Some of the race boys use .025" but they like the piston to just about "kiss" the cylinder head.

Trust me, you do NOT want to run a roller bearing GS or KZ that tight! If the pistons are "kissing" the head as you put it, the rod bearings will get destroyed!!! Ray.

[Sci85]

Ray we are not anywhere that tight. Don is at .038" and I will be close, maybe few thousandths tighter. Im not sure what the 650 redlines at but I doubt I will be going higher than 9-10k.

Don, sounds great! For some reason I thought you used 34. I did read how you made your gasket. I don't have a spare 650 to remove the liners from but I'm reasonably accurate with an xacto knife.

Will get her cut, put together and remeasure then post the numbers here.

Thanks again everyone for the assistance.

[Sci85]

I retract my previous statment. That squish is damn tight. I'm curious now what mine came to as i just slapped it together. Anyone know how much the rods can flex on these motors? Also, would a roller bearing vs plain bearing have a different tolerance for squish? and last; would the bore size make a difference in prefered squish ( I would imagine smaller pistons could run a tighter number)?

By the way boontonmike, my measurements and Don's are nearly identical whichmeans if you used oem base and head gaskets, your squish is somewhere very close to .028". I wouldn't rev it!

[boontonmike]

By the way boontonmike, my measurements and Don's are nearly identical whichmeans if you used oem base and head gaskets, your squish is somewhere very close to .028". I wouldn't rev it!

Well, I used Athena gaskets so I'm not too sure. All I know is I've had it up to 11k numerous times without any issues. I'm going to chalk it up to good luck / Athena gaskets being thicker. I'm going to be rebuilding the top end again due to Athena head gasket not sealing. I'll try and get measurements at that time to compare.

[Sci85]

Cool. I gotta believe that gasket is thicker than stock. I went down to my local auto parts store and they had plenty of gasket material. So if even the run of the mill auto house had .031" thick gasket material I gotta believe it's a pretty common thickness. Will be interesting to see though. When are you planning to do the tear down?

[boontonmike]

I'd love to do it soon, but unfortunately life and limited space from construction at home are killing me. I'm probably going to start as a winter project.