Pcv and Vacuum lines
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 20
Likes: 0
From: Slidell, LA.
Pcv and Vacuum lines
I recently install a Holley 670 avenger on a zz4 crate motor but there's not enough vacuum ports on the carb can I combine the pcv valve with any other vacuum lines without causing a problem with oil contamination of the vacuum system? thanks, hjgator
Burning Brakes
Joined: Jan 2006
Posts: 1,223
Likes: 174
From: Fort Wayne IN
I think the only things that should be pulling vacuum through the carb are your PCV valve and your vacuum advance. Everything else should be on manifold vacuum. I guess it might also depend on what emission stuff you are running.
Melting Slicks
Joined: Apr 2002
Posts: 2,337
Likes: 14
From: Norfolk VA
Okay, exactly how many vacuum ports are on your carb? The previous poster stated there should be one for the PCV and one for the vacuum advance. How about the fitting on the intake manifold? If you need more ports you can get a multi ported manifold fitting. I would not tee into the hose with the pcv valve because of oil can be sucked into the carb.
Safety Car
Joined: Jun 2000
Posts: 4,711
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From: St. Louis MO
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Here is view of bottom Holley 670 Avenger
George
George
Le Mans Master
Joined: Oct 2006
Posts: 7,123
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From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
You could use the full manifold port. Is there a port/plug in the manifold? that would be a better choice for the other systems that need vacuum- headlights and HVAC. Like Oldguard pointed out- pulling oil into the carb is possible. And a T in the brake booster is not a great idea- headlights coming on at the same time you need the brakes and it could slow down the response from both.
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
EVAP. system can be T to PCV.
Melting Slicks
Joined: Mar 2006
Posts: 3,456
Likes: 102
From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
I agree...thats how I have mine set up...and some years came from the factory this way. You can get the T that directly fits the PCV valve. I get trans and accessories off the manifold port, not off the carb. If there is no port accessible on the manifold, for your setup I would suggest.
Use front PCV port for PCV and EVAP
Use brake port for brake booster.
T off the full manifold for Vac Adv lights and accessories.
peace
Use front PCV port for PCV and EVAP
Use brake port for brake booster.
T off the full manifold for Vac Adv lights and accessories.
peace
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, kind of a dumb question. I suspect some of the usual suspects carry the actual ports let alone the pipe thread taps.
