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Author Topic:   Vacuum advance question!
Dirt Roller

Total posts: 24
posted April 20, 2003 10:14 AM
I run a Chevy 350 ( stock ) with a Holley 4412 carb. and am running with approximately 36 degrees of advance. My question is am I better off not to run a vacuum line to the intake and just leave the port on the distributor open or should I go ahead and hook up a vacuun line to the intake manifold. I'm new at all of this and am learning! I run on a 1/2 mile dirt track in Factory Stock with a 3400# Olds Cutlass. I did change the cam to the biggest one you can run with a stock torque converter! I would appreciate any input! Thanks, Kent

Dirt Freak

Total posts: 352
posted April 20, 2003 11:41 AM
you dont need vaccumn advance.

you can pull off the whole assembly and just ***** the part of the dist that turned with the vac. advance, solid to the base.

its easy and self explanatory when you get it out


Dirt Forum Racer

Total posts: 89
posted April 20, 2003 03:58 PM
Don't use the vacumn advance. When you hit the end of the straight and all the mechanical advance is in you let off the throttle and the vacumn advance goes full advance you suddenly have way too much timing.

Total timing at enough RPM to be sure all the mechanical advance is in is all you need. Mark the balancer instead of using an advance timing light.

Good luck,

Dirt Roller

Total posts: 24
posted April 21, 2003 09:56 PM
Thanks for the advice! I did find out that plugging the vacuum advance on the distributor made the car run pretty flat. I know that I need to change my gear in the rear end so I can pull more RPM's. They cannot get me in the corners but comming out of them alot of cars are eating my lunch! Oh Well - I'm LEARNING!!! Thanks guys! Kent

Dirt Newbie

Total posts: 1
posted April 21, 2003 11:34 PM
I have my vacuum advance hooked up while warming the car as it is easier during idle, I then plug the hose for racing.

Jason Sr.
Rottweiler Racing

Dirt Full Roller

Total posts: 46
posted April 23, 2003 08:11 AM
as far as screwing down the vacuum advance. where should i turn it to. can i bring it around past where it's fully advanced, and tap the raised boss that's in the base of the distributor? or, should i look to where the vac. canister pulls it and do it there?

Dirt Freak

Total posts: 352
posted April 25, 2003 06:34 PM
just use the raised boss that is there, use a ***** from the vac stuff you tossed. put the ***** thru the hole where the rod was, youll need to flatten it and maybe snip the end open. position doesnt matter.


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