Hot Rods pcv question

In the left bank (looking from front of car) of my So Cal valve cover (60s 5 fins) I cut in a standard, chrome 3 inch round breather with a 3/4 inch 90, I then hosed that to a nipple I threaded into the lowest point of the rear of my manifold (back low by distributor) with a pvc valve in the center of the rubber hose in route to vacuum.

The engine has a typical chrome, 8 inch, Sixties center manifold pipe (and button cap) on a 4barrel manifold (SBC) for inlet air.

Is this enough or do I have to drill another opening on the right bank valve cover.

Is the air inlet from the manifold tube enough?

 

bump

 

The air flow for venting while not "factory" ideal should work.
But; I think sourcing the vacuum at the back of the intake would cause the cylinders on that passage to run leaner. Carb base is a better choice.

 

Thanks Rich. The port in the back is dead center, but I do have a big vacuum port off the back of the 600 Holley that is currently capped, should I just run to that ?

 

If it pulls through the carb base port, it will be evenly distributed to all cylinders, correct?

Also, it is not a big deal to drill another port in the other valve cover, but how would the Sixties filler tube play with all of that?

 

The port in the carb base is the one to use. If you decide to put a breather on the other valve cover you could remove the front tube and plug the hole for a cleaner look.

 

i'm curious...and don't fully understand what you did when you " threaded a nipple into the lowest part of the rear of the manifold" ....was that into the intake runner or is it going straight into the lifter valley?

 

That's a good question! It sounds like it's into the lifter valley.

 

A picture is worth a thousand words would certainly apply here.

 

"Port in the back dead center" is typical of the power brake booster hook up. "Button cap" ? I assume it's the typical push on vent/oil fill cap, with wire mesh as a filter device.

I'd use the carb fitting, with the PCV valve in line, or in a grommet on the valve cover. Look at any factory set up from the day for an "open" PCV. They worked then, they'll work now.

 

He said: "the lowest point of the rear of my manifold (back low by distributor)". The power brake booster port is located toward the back, but on top of the runner for the rear cylinders, not at the lowest point. It might be fine, just hard to tell from the description.

 

Good point, being a yblock guy, and a while since I worked on a sbc, I could have made a bad assumption. But I never saw a manifold with a threaded fitting into the valley. But there's a lot of things I've never seen.

 

Hey all,
The threaded port was into the to the farthest runner in the back, just about touches the dist. (cyl -7/8). It had a pipe thread fitting which I put a brass nipple in. Anyway, capped that, and ran line right to base plate on back of carb. I am glad I don't have to put another hole in other valve cover, as I like the clean finned look with the center oil filler/breather in front of manifold. Idles awesome, with no more occasional clouds whisping out manifold pipe. Going to inspection, Monday. Thanks for all the help

 

Picking up the vacuum from a single runner on the intake manifold is less than ideal. A better way would have beenat the base of the carburetor, either at the carburetor itself, or a port that's on virtually all SBC intake manifolds just below the carburetor mounting flange. You're only getting 1/8th the vacuum, so-to-speak, and it'll be interesting to see if the spark plug for that cylinder gets a little sooty or not. OK teach, don't grade my grammar/punctuation.
I am Butch/56sedandelivery.