Quote:
Originally Posted by PDUB
Seems like I have heard that Webers don't like the LSA to be less than 108-110 degrees... trying to remember where I got that info. Sound right?
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Depends on the engine. The factory Ford race cars were tighter than that. Last FIA 289 I sent out was 106.
Webers have very short runners, essentially non-existent for all intents and purposes. Tighter LSAs increase overlap, which can introduce some reversion into the intake manifold.
Reversion doesn't matter at 7000 rpm, so you cam the engine for its intended purpose if it's a race engine. If it's a street engine, then it needs to be cammed to minimize reversion.
Most guys think, "Oh it's got Webers, I need to go 112-115 LSA", but again, it's totally dependent on overlap.