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Chevrolet/HEI distributor vacuum advance


RobAuto wrote at 2014-10-25 20:50:47
I'm sorry but I have to disagree with the provided answer for a few reasons..

1) appling vaccum does not move the rotor. Instead moves the "advance plate"

Which in the case of this dist. Changes the relationship of the hall-effect switches

Trigger in relation to crankshaft position thus changing when the coil

Is triggered to fire in relation to piston position in the clyinder.

2) the purpose of vaccum advance is not for performance but instead

is for the purpose of economy.

3) the vehicle in question did in fact, come with vaccum advance.

At some point in time it has been changed, without seeing it my guess

would be to a newer(late'80's-early '90's) style distributor.


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Ray Hawk


I can answer any questions about any Chevrolet model ever made, from the first Chevy's to the most current cars. I also will give any info I have heard about future Chevy designs and prototypes. I provide info about Chevy specs, designs, models & model years, generations, etc. I am also able to answer minor repair and maintainence questions.


Local Chevrolet club member since 1997, single-handedly restored three Chevrolets, owner of seven Chevrolets

Automotive Engineering major in High School & College, graduated with honors.

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