Originally posted by digger
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Such an extreme porting is generally needed for pure race applications. And having in mind that valve & seat material in race applications is of a much higher quality, those throats can still be closed with 42 mm valves. For durability and reliability sake most people use 43 mm valves.
40.5 throat does not make any sense for a street engine with a moderate camshaft. 39.5 throats that can help a 3.1-3.2L M20 with a Schrick 288 (for example) do not need a 43 mm valve at all. Lower displacement and/or camshaft combos definitely do not need oversized valves, just the opposite - performance will suffer if such are used.
Originally posted by digger
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Originally posted by digger
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Thanks for the discussion, Digger. It made this thread at least worth something.
I am out.
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