i just bought a holley 650 vacuum secondaries carb and would like to know what and where the various vacuum ports are. Im new to carbs so im not familiar with the parts so if you could explain in easy terms it would be appreciated.

What i need to find is the ported vacuum source for my distributers advance.

One more question.....do i hook up my pcv valve, brake booster etc all up to the one port on the carb.

Sorry if this sounds dumb, but i dont understand carbs very well yet.

Thanks in advance
Jon

 

The ported source is the one in the passegers side of the front metering block, above the idle mixture screw.

All the ports around the baseplate are manifold vacuum....hook up whatever you need to where it's most convienient. It doesn't make a difference what goes where. You can also use the vacuum port in the manifold for that stuff.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports

 

i want to add something here. dont hook pcv up to manifold vacuum. hook it in above the carb in the air filter housing. ive had some pretty strange problems with engines that use manifold vacuum for the pcv. the funniest one was a squeel when the engine shut off, sounded like a baloon if you were to pinch the end tightly and let out a little air. turned out the vacuum was so strong in the crank case that it sucked a valve cover gasket in causing this annoying noise.

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85 IROC 350 11:1keith blacks,.555lift erson roller cam,1.5 crane roller rockers,edelbrock intake,holley 4150 750dbl pumper, nitrous oxide,full length heddman headers,true dual exhaust, 11"stall converter, 700R4, 3.73 locker

 

thanks for the advice

 

PVC systems aren't designed to be hooked up that way. One valve cover goes to manifold vacuum, the other goes to a small filter or to the aircleaner housing. The idea being that it constantly cycles air through the engine and down the intake. You're not supposed to have high vacuum inside the crackcase.

It also creates a vacuum leak...which is why I don't run a PCV..just breathers on both valve covers.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports

 

Jester, how does it create a vacuum leak?

 

Thats what a PCV system does...sucks air. sucking air=leak. A leak is a leak whether it's right under the carb..or 3' down a line.

It's a minor leak, but there nonetheless.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports

[This message has been edited by Jester (edited May 21, 2001).]