Hi,
Once you get above 9.5:1, you can run regular or mid-grade fuel, but you
have to watch for pinging and if you get ping, you have to back off the
timing. Note that the higher the compression ratio, the more critical your
ignition timing becomes.
Once you go over 9.5:1, you really have to use high octane fuel. Some
states only have 91 as the premium so that would limit your optimal max.
compression ratio. For states that can get 93, you might get away with
10:1, but you need to plan you "trips" to places where you can get fuel of
you have to tote around bottles of octane boost.
Richard Good has a nice chart of how to have your head milled.
Oh, once you go above 9.5:1, you have to start thinking about reshaping
the combustion chambers to reduce possible "hot spots" as those are a def.
item in promoting pinging in a high compression motor.
In my travels, I have seen streetable TR6's with reported 10:1 motors, but
I have to hear a motor before I believe the claims of CR. 12:1 motors
sound way kool. But forget about pump gas.
:-)
rml
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Bob Lang NER/SCCA | This space for rent
Solo Chair 2008 TR6 40 F Prepared | Triumph!
Voice:781-438-2568 FAX: 617-258-9535 | Cell: 339-927-4489
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