After going back and forth about whether or not to have the hole drilled for the oil fill tube in my new Edelbrock Performer RPM intake manifold, I decided against having the hole drilled.

Now, I know I have to get new valve covers but which type? I had spoke to a mechanic and he said to be sure and get covers with two breather holes, so does that mean the covers have to have 3 holes all together? Two holes for breathers and another one for the PCV valve? And what about the oil fill hole?

My 67 Camaro has a 350 and originally had the PCV running from oil fill tube in front of manifold to base plate of my Holley 4160 carburetor with an open element air filter.

Any help would be appreciated. Thanks,

Joe

One hole in each VC is all you need. On the driver side you plumb a pcv valve over to the case of your carb (vacuum source) On the passanger side VC you can put a breather or plumb it to the base of your air cleaner. Use a funnel and the most accessable of the two holes for filling oil, just pull the pcv out of the valve cover for access. Make sure you have a baffle on the pcv side valve cover or you'll pull oil into the combustion chamber and think you have ring or valve problems. (don't ask how I know!)

DJD,

Two questions.

One hole in each VC is all you need. On the driver side you plumb a pcv valve over to the case of your carb (vacuum source)
1. So on this cover I can just run the old line with the PCV valve from the valve cover to the base plate of the carburetor (where it was originally), right?


On the passanger side VC you can put a breather or plumb it to the base of your air cleaner.
2. Is there any difference/significance between placing a breather vs plumbing it to the air cleaner?

Thanks for the help! smile.gif

You've got it!! You want to create circulation throught the block. Manifold vacuum from the base plate sucks gases from the crankcase through the pcv valve in the valve cover. Fresh air is sucked into the crankcase through the other valve cover which is vented to the base of the aircleaner or a breather. I don't think there is any benefit from one over the other.

Talk about using the 'Way Back Machine'! Dredging this one up doing a search...

What Dennis said about "Make sure you have a baffle on the pcv side valve cover or you'll pull oil into the combustion chamber and think you have ring or valve problems. (don't ask how I know!) " strikes home as I'm trying to decide how to re-run all the vacuum lines on my 350 with Qjet.

I discovered what I think is a ring or valve guide issue, which prompted me to swap the heads. The old heads came off last year and after only 900 miles, the piston tops were covered in goo. The heads didn't have new valve guides, just new seals. The rings are supposed to be new(er) and it doesn't burn oil or blow smoke out the back.

My PCV comes off the drivers side head and goes to the larger front port on the Qjet. Researching that, I come up with either T-ing the PCV hose with the brake booster line (it has the check valve already in-line), or putting the PCV hose on the large rear port that I now have the brake booster hose on, and moving the booster hose to the intake runner.

So, when I took the heads off AGAIN the other day to put the rebuild set on, the pistons are gooped up again after only a few miles since pulling the old set to troubleshoot last year... like 20 or less. :confused:

I've always suspected the PCV system as being the issue. The engine has regular factory valve covers with the baffles.. breather on one side. So how could that much oil be getting up the PCV valve and into the cylinders?
The only thing I haven't done is replace the PCV valve. I guess I'll re-route the PCV to the rear base of the carb and replace the valve.
Unfortunately the only way to see if I've fixed the issue is to pull a head... and that ain't happenin' again! I'll replace the engine before I go through that again.

My PCV comes off the drivers side head and goes to the larger front port on the Qjet. Researching that, I come up with either T-ing the PCV hose with the brake booster line (it has the check valve already in-line), or putting the PCV hose on the large rear port that I now have the brake booster hose on, and moving the booster hose to the intake runner. :confused:

You only need ONE vacuum connection - that's where your hose from the PCV valve in the driver's side valve cover connects to the large port on the front of the Q-Jet; that's the "exhaust" side of the system where crankcase fumes are "sucked" through the crankcase into the intake manifold, with the flow metered by the PCV valve.

The other side is the "intake" side; the hole in the passenger side valve cover should either have an elbow and hose into the base of the air cleaner (preferred), or just have a breather in it; that side admits clean outside air into the crankcase so the system "ventilates" the crankcase.

Yes, it's that simple. :thumbsup:

:beers:

Right, that's the way I understand it. Circulation.
So I guess it doesn't matter where I put the PCV hose on the carb then?
I'm wondering if it has anything to do with why my piston tops are gumming up after so few miles. Short of doing a leak-down test to check the rings, I guess I'll wait till these replacement heads have some miles on them to determine if the cause was the valve guides in the old heads.

Right, that's the way I understand it. Circulation.
So I guess it doesn't matter where I put the PCV hose on the carb then?I'm wondering if it has anything to do with why my piston tops are gumming up after so few miles. Short of doing a leak-down test to check the rings, I guess I'll wait till these replacement heads have some miles on them to determine if the cause was the valve guides in the old heads.

That front port on the Q-Jet was designed specifically to handle crankcase vapors; that's where the PCV hose should be connected. The power brake vacuum hose should be connected to the fitting on the intake manifold runner. Make sure you have the correct PCV valve.

:beers:

Yeah... thanks John.
Gotta go stock up on distilled water and coolant, oil filter... might as well pick up a new PCV while I'm there.

Did both valve covers have baffles on the holes? Back in the day, I switched valve covers side for side because the oil fill hole on the drivers side was up against the firewall. I switched them so the oil fill hole was on the passenger side towards the front of the engine because it was easier to add oil that way.

alan

They both have baffles...
The oil fill cap and breather are both on passenger side. Nothing but PCV on drivers side (I believe!)

You only need ONE vacuum connection - that's where your hose from the PCV valve in the driver's side valve cover connects to the large port on the front of the Q-Jet; that's the "exhaust" side of the system where crankcase fumes are "sucked" through the crankcase into the intake manifold, with the flow metered by the PCV valve.

The other side is the "intake" side; the hole in the passenger side valve cover should either have an elbow and hose into the base of the air cleaner (preferred), or just have a breather in it; that side admits clean outside air into the crankcase so the system "ventilates" the crankcase.

Yes, it's that simple. :thumbsup:

:beers:

Tought I'd hijack this topic.. I'm a bit ashamed to show the mess under my hood, but since I want to be sure..

So the driver's side hole goes to the front of the carb, where the vacuum advance is also hooked up?

If so, what bits do I need to make this happen? A T-bit to the carb for the vacuum advance and some hose that fits?

I don't have an air cleaner where I can hook up the hose coming from the breather hole, I only have the L shaped valve thing in the hole now. Is that OK? Don't want any dirt to get in my engine..

I'm cleaning up in there guys.. Any pointers would be great :p

http://i56.tinypic.com/2zptk7l.jpg

There should be a large port under the the front of the carb to run a hose from the PCV on the the drivers valve cover directly to the carb. Leave the vacuum advance hose alone, you don't want to "T" off that hose.

On the pass side valve cover is where a hose would run to your air cleaner, or put a breather there.

Flip the rod around on your throttle linkage, you want the threaded adj piece attaching to your carb, otherwise the end of the rod could hit the firewall preventing full throttle.

Push your dipstick in all the way and attach the ground strap that's hanging on the firewall to a valve cover bolt so you'll have a good ground and won't have to chase ingnition misfires in the future.

Yah the dipstick is in already! This is actually a picture I took when I bought the car. So some things are already as they should. The steering coupling joint has already been repaired as well. Wasn't really safe like this.

Thanks for the help!