Gene:
I have not personally tried it, but I have done a lot of research on
head porting. The chief advantage of extrude honing is that it allows you to
port pieces that are not suited to porting using conventional techniques.
As I recall, the process was developed by Smokey Yunick in response
to
racing rules that prohibited modification of cylinder heads through grinding
or
cutting. Since "honing" was allowed, he developed the process to port heads
using "honing".
It is expensive, and produces a nice finish, but ultimately does not
offer
any flow advantage over conventional techniques. It also does not
necessarily
deliver a shape that produces ultimate flow. It is very attractive if you
have
an intake manifold that has runners too long to port otherwise, and so would
require cutting, welding, etc.
For our LBC cylinder heads, conventional porting is less expensive
and
potentially more effective. The later 6 cylinder heads are very good, and
only
small improvements can be made in flow. Improvements for power lie mainly in
other areas (decking the block, raising compression, etc...)
If you want to see what needs to be done on a 6, get Vizard's book
"The theory and practice of cylinder head modification". Lots of LBC
examples. A book with a great deal more information, but not aimed at
LBCs is "How to build and modify Small Block Chevy Cylinder heads", also
by Vizard.
Ciao,
Vance
------------------------------
1974 Mimosa Yellow Triumph TR6
Cogito Ergo Zoom
(I think, therefore I go fast)
-----Original Message-----
From: Gene Holtzclaw [mailto:motrv8d@hotmail.com]
Sent: Wednesday, March 05, 2003 8:00 PM
To: jswarth1@tampabay.rr.com; hottr6@hotmail.com
Cc: 6pack@autox.team.net
Subject: RE: Alloy hemi x-flow head [was Next Project]
Has anyone out there ever tried what I believe was called "Extrude Hone" on
a TR6 head or any other? Its been some time since I read about it but at the
time it made great sense and the results looked great too. They forced some
sort of liquid alloy through the ports of a head at extreme pressure and the
result was a very good looking porting.
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