Steve:
The difference is small but important.
Both raise the compression ratio by decreasing the size of the
combustion chamber. However, decking the block does something that
milling the head does not; it decreases the clearance between the
top of the piston and the head. This is only important where there is
head deck over the piston as opposed to open combustion chamber.
When the piston approaches TDC, the air/fuel charge between
the piston top and the head deck "squishes" out into the open combustion
chamber. This increases the turbulence in the combustion chamber prior
to and during combustion to give a cleaner, faster burn with more power.
The TR6 combustion chamber opening in the head is not round; it
is flat on one side. This means that where the head deck covers the
piston top, there is a squish area. Decking exploits this area, milling
the head does not.
Vance
-----Original Message-----
From: Steve Hanselman [mailto:tr6@kc4sw.com]
Sent: Monday, December 22, 2003 11:33 AM
To: Navarrette, Vance; RazorBobSr@aol.com
Cc: 6pack@autox.team.net
Subject: RE: Does 0.120" really get 9.5:1 compression?
Vance,
This may be a dumb question, but what is the difference in taking
material off of the head vs. the block? Isn't the result the same, a
smaller combustion chamber?
I am confused (again)
Steve
72 TR6
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