Road Grabber
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- Apr 14, 2020
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I recently had a vacuum diaphragm rebuilt for my dual point distributor installed in a 1970 383. This Prestolite, I believe, has a "10" stamped on the diaphragm arm. It has a spring with washers inside the canister for adjustment - just for some background information.
,
My situation is this. I installed a timing tape. With my timing set at just 5 degrees before, I revved the engine and discovered my total advance was 50 degrees. I can't set my timing using total advance because it puts my timing much to retarded to run right.
I disconnected the advance hose hooked (to port) and watched the timing again. I saw that the mechanical advance total moved 28 degrees without using the vacuum advance. When I hook up the vacuum advance it jumps way up to 48-50 degrees total.
I have always thought the 383 BB are supposed to be set 36 total advance.
The distributor needs some kind of adjustment.
Do I need to make adjustment on the mechanical advancement? Vacuum advance? Is there something wrong with this distributor?
Years ago I knew where I could have my distributor setup for 14 initial advance and 36 total which worked great in my 440 engine but now I don't know anyone who can work with setting up distributors anymore.
Any help shedding light on this would be greatly appreciated.
Thank you
,
My situation is this. I installed a timing tape. With my timing set at just 5 degrees before, I revved the engine and discovered my total advance was 50 degrees. I can't set my timing using total advance because it puts my timing much to retarded to run right.
I disconnected the advance hose hooked (to port) and watched the timing again. I saw that the mechanical advance total moved 28 degrees without using the vacuum advance. When I hook up the vacuum advance it jumps way up to 48-50 degrees total.
I have always thought the 383 BB are supposed to be set 36 total advance.
The distributor needs some kind of adjustment.
Do I need to make adjustment on the mechanical advancement? Vacuum advance? Is there something wrong with this distributor?
Years ago I knew where I could have my distributor setup for 14 initial advance and 36 total which worked great in my 440 engine but now I don't know anyone who can work with setting up distributors anymore.
Any help shedding light on this would be greatly appreciated.
Thank you