Vaccum source for carb?

[johns2000]

Anyone running a carb with vacuum secondaries like the Holly street avenger? If so where are you picking up your vacuum source from?

Thanks in advance

[shopratwoody]

I haven't had a vacuum sec carb in a long time, but I think It'll open itself at WOT.
You can change springs in the vacuun pot to weaker or stronger to adjust at what
vacuum it opens. The engine is the vacuum source
Good Luck, Ron

[johns2000]

Ron

    Thanks, I was looking at one of the street avengers a guy has for sale, ( he doesn't have any instructions with it ) and tried opening the throttle plates buy way of the linkage and didn't see the secondaries open. Theres a fairly large size nipple right behind the secondaries and just thought they needed a seperate source of vacuum from the manifold? Maybe I didn't push the linkage to WOT? What would the large nipple in the back of carb be used for, brake booster?

Thanks

[shopratwoody]

On that carb, The secondaries (?) won't open without vacuun from the engine
I think. The vacuum fitting is for PCV valve I believe, same as a Holley. It should
have small vacuum fittings for vacuum advance etc.
Hope this helps. I think it is similar to a Holley as far as the hook up stuff.
I hope this helps.
Ron

[KidKourier]

johns2000, I'm running a Road Demon and the large port in back is indeed for the PVC system while the 2 smaller ports are full vacuum(front) and ported vacuum on 2nd. take vacuum line from distributor to front port and cap off 2nd one. Hope this helps. SKIP

[johns2000]

Thanks guy's that's what I wanted to know!!

[Ford Blue blood]

The vacuum port for opening the secondaries is an internal port.  If you were to pull the secondary actuator off you will see there is a cork gasket that seals the pot to the body.  The rest of the fittings are for providing either manifold or ported vacuum to any device that needs a signal.