> Ahem. Vacuum retard does not reduced engine performance. Vacuum
> retard disables itself except at idle, so baseline timing is restored
> whenever you touch the accelerator, hence no affect on performance.
> Vacuum advance only engages at cruise (moderate throttle), so
> vacuum advance disables itself at idle and at full throttle. You are
> correct about the connection; it cannot be connected directly to the
> manifold but must be connected to the appropriate vacuum port on the
> carburetor. The amount of advance does follow the manifold vacuum
> however, so in that regard it is not "backwards".
Hate to bust your bubble, Vance, but the RWA Midgets do indeed connect the
vacuum advance to the intake manifold. The carbs don't even have the vacuum
port on these. Ported vacuum gives you better performance because the signal
tells you more about what the engine is actually doing, but manifold vacuum
was easier for reducing emissions at idle which was all that they really
wanted to accomplish at the time. BTW, vacuum advance DOES NOT "disable
itself at idle", it is actually quite active there. Why the heck do you
think you have to disconnect it to properly set the timing??? The important
thing is that the vacuum unit on the distributor be connected to the signal
source that it is expecting.
David Lieb
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