>When the Factory manual gives advance degrees at different RPMs for
>mechanical and vacuum, are the two strictly additive, or does the vacuum
>advance only work under acceleration but not at constant RPM? I am
>replacing the Lucas distributor with an adjustable all mechanical advance
>Mallory dual point, and I'm not sure how to set it up
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Actually Stu-Jo?. . . You've got it kinda backwards. The vacuum advance
doesn't even come into play during full throttle runs as vacuum drops to
zero or near zero. The vacuum advance works only when there is vacuum i.e.
part throttle to idle conditions. Vacuum advance is strictly for economy
and cooler [more efficent] running during those conditions, not for
performance. For pure performance you use the mechanical advance, curving
it to utilize the optimum advance at the earliest rpm that YOUR particular
engine can use. That's kind of an over simplification of mechanical
advance, but it sorta gives you an idea of what you want.
Barry Schwartz in San Diego, CA
Bschwartz@encad.com
72-V6/5sp Spitfire ( daily driver )
70 GT6+ ( when I don't drive the Spitfire )
70 (sorta) Spitfire ( project )
73 Ford Courier ( parts hauler )
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