I'm using my 86 GL10 vacuum advance disty in the 87 XT engine I'm putting in my car. Do I need to choose a specific source for the vacuum or will anyplace I can tap into be OK??

thanks

bump

Maybe comparing apples and oranges. But, when I stripped out my manifold on my 82 brat and changed from Carter onebarrel to Hitachi Two barrel I didn't hook the vacuum advance to the ported vaccum on the carb. I used full manifold vacuum off of the manifold. I've had no problems and the brat pulls strong with good low end torque and no pinging.

 

Bill

Vacuum should increase with RPM's. That is what gives the proper advance to the distributor.

Originally posted by Qman

Vacuum should increase with RPM's. That is what gives the proper advance to the distributor.

 

I'm not debating your comment but I've checked the driveability and power with ported and manifold vacuum and the brat runs better with manifold vacuum. Besides, at fairly low RPM's, vacuum drops off anyway and its all mechanical advance has kicked in. At about 2500 RPM's the advance is topped out.

 

Bill

Check out this article. It will help you figure out what is best for your particular combo.

 

http://www.chevytalk.com/tech/ignition/Timing_Advance.html

 

Bill

thanks