I use premium pump gas. The key is that I am not running a stock camshaft.
You are correct that with a stock cam that about 9.5 to 1 is as high as you
can go because with the stock cams, the cylinder pressures get too high. I
first used a Triumph "S-2" cam and now use a grind by Elgin Cams, both with
no problems. The longer duration of the more radical cams allow a higher
compression ration - indeed in order to get the maximum effect from the
cams, you have to raise the compression. Here is a link to a tech article
about this subject. The particular article is about a Chevy V-8, but the
principle remains the same.
http://www.chevyhiperformance.com/techarticles/81679/
This is one of the reasons why I believe its important to modify engines as
a complete system (intake, engine, and exhaust), rather than doing it
piecemeal. You end up with better results that last longer.
Hugh Barber
Hollister, CA
'73 TR6
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Don Malling
Sent: Wednesday, February 23, 2005 6:52 AM
To: 6pack@autox.team.net
Subject: Re: Are u kidding me???
Hi Hugh,
What sort of gas are you using at 10.5:1?
I was under the impression that 9.5:1 was about max for 93 octane pump gas
(R+M)/2
Don Malling
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