> 1. What is a top compression ratio that will let my engine continue to
> live?
Can't speak for TRs. ALfas have been known to run 13-14:1, but fitting
pistons into the hemi combustion chamber is very difficult. Even spark plugs
make a difference with the electrode design!
>
> 2. How much power increase should I expect by changing from 10.5:1 to a
> higher ratio?
Smokey Yunik quoted 3% increase in power per point of CR in an article I
read about dyno tests on unleaded racing gas. That's why I stopped at 11:1,
as reliability is a bigger issue to me in vintage racing.
My 1600cc Alfa with 40DCOEs gave 157hp on the dyno at 7000rpm, has over
150hp from 6500 to 7500 and now has about 50 hours on it and runs like new.
So I'm happy.
Jim Hayes jeh@fotec.com Web page: http://www.fotec.com/jim.htm
Vintage racing Alfas: '57 Spider and '62 Spider Veloce
All generalizations, with the possible exception of this one, are false!
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