vacuum advance ???

jerrys84 · 05-23-2002, 11:18 AM

got really tired of playing with my Holley carb, so i bought an Edelbrock, no particular reason, just frustrated..

anyway, it has two vacuum ports on the front for the vac advance on the dist.

one port is for timed vacuum and the other is for full vacuum...

which do i use?? or does it matter??

PKRWUD · 05-23-2002, 02:20 PM

Yes, it matters a great deal. Ported vacuum and manifold vacuum are the opposite, so if you hook it up to the wrong one, your timing will advance when it shouldn't, and won't when it should. The ported vacuum (the one you feel get stronger as you open the throttle) is the one for the vacuum advance.

Take care,
-Chris

jerrys84 · 05-23-2002, 02:48 PM

thanks chris

05-23-2002, 11:18 AM	#1
jerrys84 Registered Member Join Date: Feb 2002 Location: minnesota Posts: 129	vacuum advance ??? got really tired of playing with my Holley carb, so i bought an Edelbrock, no particular reason, just frustrated.. anyway, it has two vacuum ports on the front for the vac advance on the dist. one port is for timed vacuum and the other is for full vacuum... which do i use?? or does it matter?? __________________ 91 LX 'work in progress' previous stangs; lightly modded 84GT 81 2.3 converted to 302 auto

05-23-2002, 02:20 PM	#2
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Yes, it matters a great deal. Ported vacuum and manifold vacuum are the opposite, so if you hook it up to the wrong one, your timing will advance when it shouldn't, and won't when it should. The ported vacuum (the one you feel get stronger as you open the throttle) is the one for the vacuum advance. Take care, -Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

05-23-2002, 02:48 PM	#3
jerrys84 Registered Member Join Date: Feb 2002 Location: minnesota Posts: 129	thanks chris __________________ 91 LX 'work in progress' previous stangs; lightly modded 84GT 81 2.3 converted to 302 auto

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