Timed or Full Distributor Vacuum. What Do I Have?
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Timed or Full Distributor Vacuum. What Do I Have?
My new Edelbrock carb arrived today and I have a choice of timed or full vacuum for the distributor advance. The pic shows the current Holley setup. What do I have at the moment?
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: Timed or Full Distributor Vacuum. What Do I Have? (paul67)
It looks like you have full (manifold vacuum) If there is vacuum at the port at idle then you have manifold vaccuum. Ported vacuum build as air velocity increases manifold vacuum is below the throttle plate... ported vacuum is above the throttle plate.
[Modified by Larry B., 2:04 PM 6/24/2004]
[Modified by Larry B., 2:04 PM 6/24/2004]
Drifting
Joined: Dec 2002
Posts: 1,946
Likes: 28
From: Long Beach CA
Re: Timed or Full Distributor Vacuum. What Do I Have? (paul67)
It looks like you're coming off manifold vacuum. The easiest way to tell is to pull the line off the vacuum advance with the engine idling. If you hear a sucking sound when you put the line near your ear, and can feel suction with the end of your finger, and the idle speed gets slower, it's manifold vacuum.
