[RodFather]

Need help...intake vacuum port

I have a 350 chevy with an aluminum intake. Edelbrock carb.

I am working on setting up the vacuum.
For the port right behind the carb. what else would you run off this port besides the vacuum to the transmission?

The carb. has three tubes running off the front. I am thinking a small one runs to the vacuum advance and I would cap the other small one off. This leaves the bigger tube in the middle...Where does this go?

 

[strikingthematch]

One should go the the PCV valve on one of the valve covers. Nromally there is a port in the back of the carb. at least on a holly that runs to the PCV valve. The front should have one that runs to the vac. adv. if you have it on the dis. and the other to the trans. It is also possible ot have a vac. canister that has a hose hooked to it.

Chris

 

[[email protected]]

Large one, either on carb or intake will go to vac booster for brakes.

 

[RodFather]

The brake booster line fits perfectly in the rear on the carb. This is what I am going to do let me know if I should change anything.

brake booster into rear of carb
small tube out front of carb to vacuum advance
cap the other small one off
big tube run to valve on valve cover
use one barb pipe fitting off intake to transmission vacuum line

Ok, thanks guys sounds like I have a plan now.

 

[red65mustang]

Rodfather,

Call Edelbrock 213-781-2222 and order the manual for your carb.

It's very well written and complete for install and tuning and worth the bucks.

 

[Old School Nut]

well the manual does say, i think you can still download it for free of their web page. however on my truck the Big rear one goes to the brake booster, the big one in the front of the carb in the middle is for the PCV and the left small one is ported vacuum and the right small one is manifold vacuum (you choose what you want for your ignition) i have my trannys modulator hooked up to a port in my wieand X-celerator intake port runner.. but to be sure i would download the manual.

-Leo-

 

[batman09]

I run full manifold vacuum on my edelbrock 1405.My nova runs alot better vs ported.this is one of the olded arguments on this forum(full vs ported vacuum).bm

 

[Gene Neal]

Vacuum

Here is a copy of a post I made a while back in the Engine Forum. You might want to look at it and other posts made there.

I have been reading all the post's and in less I missed something, here is what I see missing: the distributors the answer to the question. There are Vacuum advance distributor's and then there are rodder advance distorter's. And then there are to deferent place to get the vacuum from. One is from the carburetor above the throttle plates, the other is below the throttle plat's or intake manifold vacuum. Now it has been quite awhile but sense I worked on this problem, but the full vacuum from the intake manifold or from below the throttle plats on the carburetor is for the vacuum advance distributor and the rodder advance distributor vacuum comes from the carburetor above the throttle plat's. They are very deferent in the way they advance the timing on the engine. I know that there are other types of distributors out such as the Rev Pole just to name one. Some time you have a problem when you switch carburetors or distributors. If I'm wrong about this I'm sure there will be someone on here that will set it straight. And that is OK too. Just something to think about! ------------Gene Neal

 

[batman09]

I can see it now....its starting all over again...full vs ported...it gives me nightmares .....make it stop!!!!

 

[red65mustang]

Gene

You are correct on the Edelbrock dist advance choices,

one is vacuum from idle on up

the second is 0 vacuum till about 1200rpm+.

Depends on the design of the advance unit which to use.

You can put a "T" in the line on the rear and do both tranny vacuum and brake vacuum.

Some tranny vacuum modulators like it this set up, some don't.

Hooking up to a single intake runner gives a weaker chattering/pulsing signal to the modulator which is spring and diaphram activated.

$2, plastic T and some hose to try it

 

[wildman926]

I can see it now....its starting all over again...full vs ported...it gives me nightmares .....make it stop!!!!

Batman-

I had to change back to ported after switching to full. FOR MY COMBO- it was too much of a drop in rpm going from park to gear. The cam is way more noticeable with it in ported. I just really liked the cooling properties going with fulltime advance. Dropped the temp down 10-15 degrees while it is a hot day. It took too long for the car to warm up though here in the winter.