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Speedy Squirrel Speedy Squirrel is online now
Rocket Scientist
Join Date: Jun 2008
Location: Detroit
Posts: 898
Also, I need to point out that the vacuum retard curve posted by boosted79 is for the single hose USA setup, which is relatively uncommon. In this case there is no boost retard. The centrifugal advance at 4000 RPM (2000 RPM cam) is the same 16 crank degrees (8 cam degrees). The vacuum advance is disconnected and the timing is set to 26 crank degrees at 4000 RPM. That means there is 10 degrees of static timing (26 - 16 = 10) With the vacuum hose connected the timing at idle is 10 static + 0 centrifugal - 20 = 10 degrees retard at idle. Note that this setup gives about the same ful boost timing as the dual diaphragm distributor.

Last edited by Speedy Squirrel; 06-30-2017 at 04:33 PM..
Old 06-30-2017, 04:20 PM
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