I was always curious of what advantages or disadvantages of each approach would be to achieving high compression results (milled head/flat topped pistons vs. high domed pistons). I would love to hear peoples opinions and theories on this matter.

 

Milling the head effectively reduces p2v clearance but so do large domed pistons. The ideal dome on a piston is still no dome at all. Unfortunately, to achieve some compression, a dome is needed.

 

domed piston with milled head
go for the max

 

Milling the head on a head like the H22 will decrease your quench height (top of piston to bottom of chamber quench pad). This is good. You will also want to clay the pistons. Shoot for a minimum piston to head quench pad clearance of .030, a minimum piston to intake valve clearance of .040, and a minimum piston to exhaust valve clearance of .060. As CC said above, the flatter the piston the better for flame propogation, but you can only mill the head so far so you have to fill up the chamber with dome.

 

Smaller dome on the piston is good for 2 things. Better flame travel (like already stated) and allowing the piston to be lighter reducing rotating mass.

 

i was wondering how hard is it to clay a motor? can you DYI?

 

Look here: http://www.rndauto.com/rantabuild3.htm

 

dome filling the chamber dosnt effect honda's nearly as much as some other engines... fill the chamber up and let it roll

 

A high dome can also hinder flow coming out of the valve. The extent of this will greatly depend on the motor though.