Thread: 348 Running warm

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I do know to disconnect and plug the port for the advance for base timing , but one thing I never understood is I think that the port vacuum is the factory spot, so I always wondered what the advance weights in the dist are for. To add to that , then I never am quite sure if total advance should checked with the vacuum hooked up or not. From what I understand now, use the weights for total advance and plug the dist to constant vacuum after its all timed.

Originally Posted by 53 Chevy5

I do know to disconnect and plug the port for the advance for base timing , but one thing I never understood is I think that the port vacuum is the factory spot, so I always wondered what the advance weights in the dist are for. To add to that , then I never am quite sure if total advance should checked with the vacuum hooked up or not. From what I understand now, use the weights for total advance and plug the dist to constant vacuum after its all timed.

I do know to disconnect and plug the port for the advance for base timing.
Great!

but one thing I never understood is I think that the port vacuum is the factory spot.
Pre 70’s cars used manifold vacuum advance (all of the muscle car years), the 70’s brought us the SMOG motors (de-tuned) and the vacuum advance was moved to port or timed vacuum source (above throttle, no vacuum at idle) to raise idle temperatures and burn hydrocarbons.

so I always wondered what the advance weights in the dist are for.
Mechanical advance, allows the motor to start easier and helps in tuning the power curve for street use, race motors are locked out (no mechanical advance).

To add to that , then I never am quite sure if total advance should checked with the vacuum hooked up or not.
Vacuum disconnected.

From what I understand now, use the weights for total advance and plug the dist to constant vacuum after its all timed.
Correct! There are times with some motors that using the ported vacuum is advantageous. Some motors use no vacuum advance as it has nothing to do with horse power but rather economy.

Originally Posted by 36 sedan

I do know to disconnect and plug the port for the advance for base timing.
Great!

but one thing I never understood is I think that the port vacuum is the factory spot.
Pre 70’s cars used manifold vacuum advance (all of the muscle car years), the 70’s brought us the SMOG motors (de-tuned) and the vacuum advance was moved to port or timed vacuum source (above throttle, no vacuum at idle) to raise idle temperatures and burn hydrocarbons.

so I always wondered what the advance weights in the dist are for.
Mechanical advance, allows the motor to start easier and helps in tuning the power curve for street use, race motors are locked out (no mechanical advance).

To add to that , then I never am quite sure if total advance should checked with the vacuum hooked up or not.
Vacuum disconnected.

From what I understand now, use the weights for total advance and plug the dist to constant vacuum after its all timed.
Correct! There are times with some motors that using the ported vacuum is advantageous. Some motors use no vacuum advance as it has nothing to do with horse power but rather economy.

Thanks, I feel like I just left vacuum advance college. I will double check everything this weekend.

Originally Posted by 53 Chevy5

Thanks, I feel like I just left vacuum advance college. I will double check everything this weekend.

Sorry, didn't mean it to be a lecture.

Originally Posted by 36 sedan

Sorry, didn't mean it to be a lecture.

No really, I wasn't be sarcastic, I really do understand better. Thanks

Originally Posted by 36 sedan

Sorry, didn't mean it to be a lecture.

Originally Posted by 53 Chevy5

No really, I wasn't be sarcastic, I really do understand better. Thanks

I thought that you did great too, 36 sedan! Clear, concise answers with no drama. Nicely done.