Machining cylinders?

[mahoneygod]

Anyone know where I can get the tops of my cylinders machined down to fix my squish?

[brad black]

you machine the base.  machining the top puts the coating at risk as you will disturb it.  machining the bottom on affects the base gasket surface.

you need someone with a lathe large enough to spin the cylinders (they're not very big) and an understanding of what you're trying to achieve.  any general engine machinist should be able to do it.

[mahoneygod]

What im trying to do is square up my cylinder to my head. I measured my squish and my numbers are off all the way around. From .73 mm to .34 mm. Will machining the base of the cylinder fix that? I wonder because of the sleeve that slides into the case.

[Langanobob]

What im trying to do is square up my cylinder to my head. I measured my squish and my numbers are off all the way around. From .73 mm to .34 mm. Will machining the base of the cylinder fix that? I wonder because of the sleeve that slides into the case.

I'd try measuring the height of the cylinder at 4 points around the circumference, from the base flange where it mates to the case up to the top of the cylinder head gasket surface.  If the height measurements  show the same .4mm discrepancy around the cylinder then you've found a problem.   If the measurements are all the same, then you've at least eliminated one potential source of the problem.

[Speeddog]

+1 on Langanobob's suggestion.

I doubt that your cylinder(s) are out of parallel.
And angle-milling them is a recipe for disaster.

[mahoneygod]

Ya. I purchased hc from fbf and the piston height on the intake side and exhaust side are different. They are telling me the squish should now be set to 1.1 mm to 1.5 mm does that sound correct?

[brad black]

if the pistons are milled (rectangular-ish dome in middle), not spun then they certainly could be that far off.  i'd get someone to machine them properly or send them back

[mahoneygod]

I was wrong, so so wrong.

The high comp pistons I purchased from Fast By Ferracci are .25 mm smaller in diameter than the stock pistons. When I was checking the squish the piston was rocking in the cylinder giving me screwy numbers everytime. Why it took me so long to figure this out is beyond me and I'm kinda surprised no one here thought about it either.

The measurement on the hc is 93.25 mm across, stock is 93.5
Are the hc to small to run?
Did you guys think they sent me the wrong part?

Ive explained all of this to them as we have been going back and forth on the squish subject as well and I'm awaiting a response.

Any thoughts are appreciated

[brad black]

you measure the diameter at the bottom of the skirt.  the diameter of the crown is somewhat irrelevant.

they will rock around without rings.  i just push both ways and take an average.

[mahoneygod]

They rock like that with the rings. The measurement at the widest part of skirt is much closer at 93.95.
So i should use the measurement at the 3 and 6 o'clock positions or above the wrist pin and try and get that as close as possible to 1.00 mm since there is no rock in that direction and consistently measure out to .38-.40 w/o a base gasket.
Since I have a .3 and .4 base gasket I should come up with a 1.1 mm squish give or take?

Thanks for your input and advice. If you guys are ever in Vegas I owe you some 

The collective knowledge here is incredible 

[mahoneygod]

Alright talked to the guys at wiseco (excellent customer service) and they confirmed using the measurement above the wrist pin as my squish soooo im going for it.

[mahoneygod]

Shes back together and running! Thanks for all the help guys