JG1966
Well-Known Member
I was always under the impression that on a vacuum advance, the amount of timing is set (double what's marked on arm) and you are adjusting the amount of vacuum needed to make the timing come in. My 340 MP distributor from Jegs (part no. 40500) says it's the other way around, at least according to paperwork.
Has anybody used one of those?
On instructions, it says "The vacuum advance canister is factory set to produce 5-7° of crankshaft advance at 15” of vacuum. .... Turn the wrench clockwise to increase the amount of vacuum advance or counter-clockwise to decrease."
That sounds wrong in a couple of ways. For one, I think it should read 10-14° of crankshaft advance. Also, I only get about 12" of vacuum at idle (I'm using manifold port), so if the 15" isn't adjustable, it doesn't do me much good. I called Jegs and didn't really get clarity on it.
I guess my question is do they make vacuum advance with adjustable timing degrees rather than vacuum needed OR are these instructions maybe inaccurate? Thanks
Has anybody used one of those?
On instructions, it says "The vacuum advance canister is factory set to produce 5-7° of crankshaft advance at 15” of vacuum. .... Turn the wrench clockwise to increase the amount of vacuum advance or counter-clockwise to decrease."
That sounds wrong in a couple of ways. For one, I think it should read 10-14° of crankshaft advance. Also, I only get about 12" of vacuum at idle (I'm using manifold port), so if the 15" isn't adjustable, it doesn't do me much good. I called Jegs and didn't really get clarity on it.
I guess my question is do they make vacuum advance with adjustable timing degrees rather than vacuum needed OR are these instructions maybe inaccurate? Thanks
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