PCV mess 1960 352

[statue4]

Apologies for starting yet another PCV thread. I've read several and am still scratching my head.
I recently picked up a 1960 with a 352 and a partial PCV conversion. It has the stock valve covers with holes drilled.
-The drivers side one has a rubber oil cap - not breather.
-The passenger side valve cover has a grommet with a 90 degree elbow type PCV. From that PCV is a hose to the rear of the base of the carburetor, and to the firewall. I presume the firewall connection is for vacuum windshield wipers.
-The oil fill tube has a breather-type cap - not sure if it is original.
-Where the draft tube originally connected to the intake manifold is empty, though: a big ole hole for crankcase fumes to come and go as they please.
On my 400 mile drive home after purchasing the car I tried to plug that draft tube hole with a rag. On my next fuel fill up I noticed that oil seemed to seep or spray out near the PCV and oil fill plug on both valve covers. I'm guessing that this is either because the drivers side has a plug instead of a breather or because the PCV is either clogged or too small. For the rest of the drive I remove the rag from the hole and just let the crankcase breathe the atmosphere.
Moving forward I see three options:
1. Replace the oil fill plug in my drivers side valve cover with a breather and plug the hole in the rear of the manifold.
2. Plug the valve cover holes and set up a PCV valve from the rear of the intake manifold to the carb.
3. Plumb it so that the PCV "source" comes from both the rear of the intake manifold and the passenger side valve cover. Then have a breather on the oil fill tube and on the driver's side valve cover.
In any case, is it okay to have the PCV connected to only the rear of the carb? The brake booster vacuum source comes from a fitting on the front portion of the manifold. Would I need to connect that brake booster vacuum source to the PCV vacuum source to equalize pressure among the intake planes?

Unfortunately The Bird Nest is out of 6A665, the 61-64 intake manifold PCV adapter. It looks like I would have been able to install that in my vacant draft tube hole.

This is my first attempt at including photos. Let me know if they are visible to you.

[jopizz]

Your pictures are showing up fine. From 1962-1965 Ford removed the breather tube and installed a port to connect to the PCV valve and into the carburetor base. That was basically an open system. In 1966 Ford went to the closed system with the PCV valve in one valve cover going into the carburetor base and the oil fill cap in the other valve cover venting into the air cleaner. That's certainly the more efficient system and the way I would go. However it does require an air cleaner with an intake port. How to best block off the draft tube opening is another issue. I've never tried it. You could always replace the stock intake with an Edelbrock aluminum intake depending on your budget.

John

[statue4]

Thanks for the reply. I think I'll do that: install a breather in my driver's side valve cover and install a plug in the draft tube hole.

[pbf777]

The P.C.V. plumbing should not be shared with other VAC system requirements; as the P.C.V. system is basically just a controlled, by the P.C.V. valve, vacuum leak to atmosphere, in this case plumbed to the crankcase atmosphere and hence does not provide the work effort as intended of the "closed" VAC system.

And technically, the plumbing from air cleaner into the valve cover (crankcase volume) is actually intended to be the P.C.V. system "inlet" to the "crankcase", this with filtered air being drawn from air cleaner and exiting through the P.C.V. valve on the opposite valve cover, or as on the earlier versions the back of the intake in place of the road draft tube, plumbed to the carburetor base-plate or spacer below the carb., this utilizing the vacuum value as generated from the lower manifold pressure to create flow motion.

But, as the engine ages, clearances in the piston, ring and cylinder bore opens up, and at greater throttle openings, greater sums of blow-by are experienced, here the P.C.V. system becomes overwhelmed, the crankcase becomes pressurized, and at this point the air will tend to flow backwards from the valve cover to the air cleaner, and later often 'pop' the P.V.C. valve out of the valve cover grommet it's plugged into.

Scott.

[statue4]

The vacuum hose that I have going to the firewall, presumably for the windshield wipers - should I have that connected to the brake booster vacuum source or to the PCV vacuum source?

[jopizz]

It's supposed to go to the dual action fuel pump. If you just have a standard fuel pump then run it to the intake manifold vacuum. You should have a T connector in the intake. One port goes to the brake booster and the other port goes to the fuel pump. Just using manifold vacuum will not give you much in the way of wipers. Having it connected to the fuel pump gives slightly better performance.

John

[statue4]

Unfortunately I have a standard fuel pump, without a vacuum pump.

I plugged the old draft tube hole with Dorman 02610:

I put a breather on the driver's side valve cover and replaced the oil fill tube breather. They both get fresh air from the air cleaner.


While not entirely related to the PCV, I found the next air-related problem I'll have to tackle: I had suspected a vacuum leak because of high idle and I found it. I hear a hissing sound and the idle increases when I apply the brakes, so my brake booster needs to be rebuilt. Bird Nest online catalog shows them, but it'd probably end up being in the $500 range and I am not quite ready for that. Any reason why I couldn't cap the vacuum line and just drive it without power brakes for a while?

[statue4]

Well turns out I did not find all of my vacuum leak. With the booster line capped off it still idles high.

[jopizz]

Do you have the windshield wiper hooked up to vacuum. That will often leak either internally or where the T connector is behind the dash. Remove vacuum from the wiper and see if that helps.

John

[statue4]

Do you have the windshield wiper hooked up to vacuum. That will often leak either internally or where the T connector is behind the dash. Remove vacuum from the wiper and see if that helps.

John

No, I have the windshield wiper disconnected too. I put a cap on the T fitting between the carb and PCV.

[jopizz]

If you have all your vacuum ports blocked then you can only be losing vacuum around the carburetor base or possibly the vacuum advance in the distributor. How do you know your high idle is caused by a vacuum leak? Did you adjust the carburetor?

John

[statue4]

If you have all your vacuum ports blocked then you can only be losing vacuum around the carburetor base or possibly the vacuum advance in the distributor. How do you know your high idle is caused by a vacuum leak? Did you adjust the carburetor?

John

I feel foolish, but it was an easy fix. You will shake your head. I had the idle screw turned all the way out, but I just needed to remove and adjust the linkage.