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Old 03-15-2007, 02:21 AM   #6 (permalink)
Huron
Junior Member
 
Join Date: Mar 2007
Posts: 19
Quote:
Originally Posted by Mr. King View Post

So what you are saying about the timing is that I should forget about looking at the timing tab with a timing light and hook my vacuum guage up and advance the timing for the highest vacuum reading without any pinginig? I have heard of using a vacuum guage to set the lean/rich mix, but not timing. At this point if it keeps me from ripping into the motor I will try it.

As far as the vacuum advance...I have used a manifold vacuum source and all of the carb vacuum ports with no difference. Also, I don't have power brakes.

Any other way to check the vacuum advance on the distributor?
Mr. King,

Yes, with a higher duration cam you will find that the stock timing specs are irrelevant. For a test, disconnect and plug the vacuum line going to the distributor. Using a timing light with the dial, or knob to adjust for advance, verify that you have ~36 degrees timing at 3000 rpm. At this point, don't worry about where your base timing is. If it runs fine there, you found the problem - not enough initial timing. Use the same timing light to verify the vacuum advance. With the advance connected and the engine brought up to a decent idle, you should have about 10 more degrees advance than when it is disconnected. If not, look into getting a different vacuum advance unit. Your's may be defective, or not appropriate for the cam that you are running.

Huron
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