Guest aircoolguy Posted April 14, 2014 Share Posted April 14, 2014 As was developed on the AACA Forum, Side Draft Franklin valve clearance specs varied by Series as determined by camshaft profile as follows:Series 14 - .007" ColdSeries 15 - .003" Intake, .006" Exhaust HotSeries 16,17, 18 - .007" HotHere's what's happened to my Series 15:After the AACA discussion I took the bull by the horns and changed the clearances from .007" and .007" HOT to .004" and ,007" HOT.(I didn't have the courage to close them all the way to .003" and .006")There was an immediate change in the car's behavior: Instead of shifting down to climb that snake-like hill going up to Ed's, the car just calmlyclimbed that hill in high gear without apparent strain.Is it possible such an apparently small change could make such a big difference? Link to comment Share on other sites More sharing options...
rob.webb Posted April 14, 2014 Share Posted April 14, 2014 I am by no means an expert, but in my experience that kind of change is possible. Depending on you cam, a change of 0.004" could cause your intake valve to open a lot longer allowing much more fuel to enter the combustion chamber. I have noticed a big increase in performance after valve clearances are re-set on my cars. Link to comment Share on other sites More sharing options...
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