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Pcv and Vacuum lines

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Old 07-31-2009, 08:50 PM
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hjgator
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Default 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
Old 07-31-2009, 09:18 PM
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bluthundr
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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.
Old 07-31-2009, 09:31 PM
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Oldguard 7
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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.
Old 08-01-2009, 09:33 AM
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Here is view of bottom Holley 670 Avenger

George

Old 08-01-2009, 09:44 AM
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marshrat99
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I've the 670 SA on my 79. Use a T on the one marked for the power breaks or T off of the one coming from your intake manifold if you need extra vac lines.
Old 08-01-2009, 09:48 AM
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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.
Old 08-01-2009, 11:21 AM
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Ganey
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Originally Posted by hjgator
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
EVAP. system can be T to PCV.
Old 08-01-2009, 11:38 AM
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CheezMoe
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Originally Posted by Ganey
EVAP. system can be T to PCV.
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
Old 11-06-2009, 10:53 AM
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KeyWestJack
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Are there kits for installing a vacuum port on the manifold?
Old 11-06-2009, 11:52 AM
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Originally Posted by KeyWestJack
Are there kits for installing a vacuum port on the manifold?
Sure. It's called a drill and tap.
Old 11-06-2009, 02:51 PM
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Originally Posted by FB007
Sure. It's called a drill and tap.

Ya I know , kind of a dumb question. I suspect some of the usual suspects carry the actual ports let alone the pipe thread taps.

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