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Hei timing question for sbc

526 Views 7 Replies 6 Participants Last post by  74c20
Hello I've been told by a few people that you can put number one wire anywhere you want on the distributor cap aslong as the rotor is at number one and the wire lines up with it the cap can be in any position for more adjustment... Is this correct?
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It usually works fine to install the distributor with the vacuum advance pointing at about the middle of your passenger side fender. This should give you enough travel in both directions to set the correct timing. Then install the cap and pick your #1 cylinder as a starting point.

One tip - experiment a little with setting the timing on your SBC quite a bit more advanced than the factory book shows. The factory setting may be as low as 4 degrees BTDC. However, 12 is usually fine, and it might even take more. The compression ratio is really low on these smog-era engines.

Each time you bump up the base timing, set the idle back down to about 650 to ensure there is no mechanical advance being added.

Then run the rpm up and use a dial-back timing light to verify your mechanical advance. It should be about 18-20 degrees additional.
 

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Yup, put it wherever you want. If you run out of adjustment (vac canister hits something) you can pop all the wires over one post and gain more adjustment.

The old points distributors had to be "on the right tooth" because the points had to close and open at a specific time relative to the spark. Since HEI has an 8-point induction trigger, it doesn't matter.
 

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Nice to read the above responses. I've read threads (not on this forum) where people say things like, "Number 1 plug wire must be on a specific cap terminal." Or "The distributor gear is off by one tooth."
 
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