How much can be shaved off safely?

[plattey]

How much can be taken off the cylinder head safely (and not run into knock or have to run e85) to increase compression ratio? 0.03"? 0.05"? Would be running stock base gasket and head gasket (not mikes head gasket either it's thicker than stock!). Thanks!

 

[plattey]

I calculated it out based on a stock compression ratio of 8.4:

If 0.03" is milled off the cylinder head, the new compression ratio is 9.01:1
If 0.05" is milled off the cylinder head, the new compression ratio is 9.476:1
If 0.05" is milled off with combination of removing the 0.020" base gasket: 10.0:1

I'll post hand calcs when i have access to a scanner

 

[plattey]

http://i1112.photobucket.com/albums/k485/plattey/compressionratiocalcs.jpg

please chime in if you see something wrong in calc's

 

[JasperLP]

Here's a quote from my Clymer's, page 60. "Head milling must not exceed 0.010 in. or piston-to-head clearance will be affected." Just somethin' I read.

 

[aldo5468]

Don't forget that it changes cam timing -

 

[blackbetty]

Why not just lose the base gasket and leave the head alone?

Good link:

http://www.xs650.com/forum/showthread.php?t=5923

 

[plattey]

Why not just lose the base gasket and leave the head alone?

Good link:

http://www.xs650.com/forum/showthread.php?t=5923[/QUOTE

I'll give this a try, thanks Blackbetty!

 

[plattey]

Why not just lose the base gasket and leave the head alone?

Good link:

http://www.xs650.com/forum/showthread.php?t=5923

I'll give this a try! Thanks blackbetty!