Richard:
Get a copy of Vizard's book, "Theory and practice of cylinder head
modification".
He has specific sections on the TR6 cylinder head. For the later head, he claims
that the ports should not be enlarged (gasket matched) because they are too
large
already. For the earlier head, he still does not recommend gasket matching.
Instead
the valve pocket and the combustion chamber need some attention, as I recall.
Bottom line; Don't blindly do a gasket match. Follow Vizard's design as
he
has the benefit of lot's of experience and a dyno. Blind gasket matching is much
more likely to be detrimental than helpful. Surprising, but true.
The valve pocket is the main restriction, because that is where the
incoming
air/fuel charge must turn a corner, and this is where it slows down. Gasket
matching is
sexy, but does little for flow in most cases.
You can get Vizard's book from http://www.amazon.co.uk, or you can get
80% of the material of interest on line at
http://www.141.com/triumphs/vizard.pdf. You will not see anything there about
gasket matching, just a careful reshaping of the valve pocket, and a
streamlining of the region around the valve guide.
Cheers,
Vance
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net]On
Behalf Of Richard Seaton
Sent: Tuesday, September 30, 2003 5:31 PM
To: 6 Pack Good email address
Subject: 9.5:1 compression, hotter cam and dist setup
<snip>
This is what I'm curious about, the compression will be increased to 9.25 or
9.5:1, three angle valve job, match intake and exhaust ports to the head,
Petronix electronic ignition and with either and S2 cam or Piper 270 with
triple ZS carbs. Any comments out there on what I'm getting ready to do?
<snip>
Richard Seaton
RSH17@msn.com
View My restoration @ (http://groups.msn.com/Richards69TR6Restoration)
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