Help with PVC routing

[Jeff Erwin]

71 sbee, 440x6. Running very well. However, I am not sure what the PVC port on the center carb is supposed to do. Actually I know it's 'supposed' to tie to the driver-side valve cover to draw gasses back into the intake to be burned but my valve covers don't have a port for that. So the PVC port on the center carb, which I assume is an intake and not a source of vacuum, is connected via vacuum hose to one of the two vacuum ports on the power brake canister. The other side of the brake canister goes to the output of the vacuum canister, meaning I think I am applying vacuum to the carb PVC port. The vacuum canister input comes from the manifold vacuum port on the back of the intake manifold. Plenty of vacuum at the vacuum canister and the brakes work great.

Sometimes I mentally decide this is all ok, but I have a nagging feeling that it isn't right. It seems like the routing I have is pulling from the center carb port which isn't the way it is supposed to work, I think. If I don't have a PVC valve on the valve cover, where should the PVC intake on the center carb be routed to?

The engine came this way, I am just now getting to the smaller details and I need to figure this one out.

 

[R/T Boy 67]

You should have a working PCV system. I would change valve covers to ones with a port, and a baffle. The big port on your carb is a vacuum source designed for the PCV valve to be connected to.

 

[Jeff Erwin]

You should have a working PVC system. I would change valve covers to ones with a port, and a baffle. The big port on your carb is a vacuum source designed for the PVC valve to be connected to.

I am aware that the port at the base of the center carb is a vacuum source, however 90+% of the valve covers out there do not have a PVC port. The question is, without said port and not wanting to change my valve covers, where can I route the PVC port on the carb to where it won't do any harm or affect the performance of the engine?

 

[BeepBeepRR]

Rubber caps come to mind...

 

[R/T Boy 67]

I strongly recommend a PCV system, but if you don't want one, then leave it as it is. If I am reading it correctly then it is fine the way it is hooked up. The carb port and the manifold port are the same source. There is no problem hooking them together via the brakebooster. Did I mention that I recommend a PCV system, and I wouldn't even consider driving my street car without one.

 

[Jeff Erwin]

I strongly recommend a PVC system, but if you don't want one, then leave it as it is. If I am reading it correctly then it is fine the way it is hooked up. The carb port and the manifold port are the same source. There is no problem hooking them together via the brakebooster. Did I mention that I recommend a PVC system, and I wouldn't even consider driving my street car without one.

Got it. My valve cover has the opening for adding oil, currently has a rubber plug. Can I fit a PCV valve in it somehow?

 

[R/T Boy 67]

The opening for the PVC needs a baffle inside the valve cover to prevent oil from being sucked into the engine. You also need a vent on the other valve cover as per the picture. It would probably be easier to get valve covers that are designed for it.

 

[Jeff Erwin]

Just ordered one that will fit the oil opening on the driver side. Standard 1.25" opening. Thanks for the great pic.

 

[Mike67]

Not trying to knitpick here but this is one of the things that drives me absolutley nuts and I dont know why...its a PCV not
PVC.
PVC is polyvinylchloride, PCV is Positive Crankcase Ventilation

 

[MarPar]

?

 

[MarPar]

Not trying to knitpick here but this is one of the things that drives me absolutley nuts and I dont know why...its a PCV not
PVC.
PVC is polyvinylchloride, PCV is Positive Crankcase Ventilation

Ha! Great minds...

 

[steve340]

As mentioned earlier make sure the PCV valve is well baffled or it will suck oil out of the engine.
A lot of aftermarket covers have very poor baffling.

 

[Jeff Erwin]

As mentioned earlier make sure the PCV valve is well baffled or it will suck oil out of the engine.
A lot of aftermarket covers have very poor baffling.

Thanks. The baffling is there. Covers are made by edelbrock, seems like I should trust them to do it right...

 

[Jeff Erwin]

Not trying to knitpick here but this is one of the things that drives me absolutley nuts and I dont know why...its a PCV not
PVC.
PVC is polyvinylchloride, PCV is Positive Crankcase Ventilation

True that! The issue I seem to be having is that my spall clacker is constantly wanting to change pcv to pvc.

 

[steve340]

Not sure about Edelbrock covers might pay to check them. I modify all baffles in any case.
Stock is pretty good - see how the Edelbrocks match up.

 

[Jeff Erwin]

Not sure about Edelbrock covers might pay to check them. I modify all baffles in any case.
Stock is pretty good - see how the Edelbrocks match up.

How do you modify them?

 

[Jeff Erwin]

Not sure about Edelbrock covers might pay to check them. I modify all baffles in any case.
Stock is pretty good - see how the Edelbrocks match up.

https://www.summitracing.com/parts/edl-41923/make/dodge

This is what I have.

 

[steve340]

I make my own generally sometimes raise them up away from the oil. The idea is the valve can only see "air" but not raw oil.

 

[Mike67]

True that! The issue I seem to be having is that my spall clacker is constantly wanting to change pcv to pvc.

No worries, not many things trigger me, Ive never understood why this is a peeve of mine
Also they make some valves that have an intergral screen to help alleviate sucking oil into the manifold. Unfortunately I dont have a part number.
My spell checker is always on auto-incorrect... fat fingers and a cell phone key board are not good bed fellows...lol!

 

[R/T Boy 67]

Sorry about the PVC thing. Not enough coffee yet. I fixed it.