Switching To Closed Crankcase-type Oil Cap On 1966 289

[Lee317]

I have a 1966 289 coupe that was originally manufactured without the California emissions setup. I'm having some oil blow-by and several folks have suggested to me that I ditch the breather cap and go with a closed crankcase type breather with a hose from the oil cap to the air cleaner.

The problem is, I can't find any how-tos online or anybody talking about this mod. How do I modify the existing air cleaner housing or should I just buy a new cleaner with the hose nipple on it already? Also, do I attached the hose from the new oil cap just attached directly to the air cleaner or is a PCV valve or spark arrestor required in the middle?

Any help is greatly appreciated!

 

[horse sence]

I have a Cobra oval air cleaner on my 1935 Ford truck ,i used an aftermarket PVC valve grommet and a 90* plastic fitting that i think i got at Auto Zone .I drilled the correct size hole for the grommet on the bottom of the air cleaner and pushed in the plastic fitting and hooked the breather cap to the fitting with The correct size hose .It only took a few minutes to do . Some of the Chrome air cleaners have the hole stamped but not punched out . A PCV valve Will help more than anything if you do not already have one hooked up.

 

[horse sence]

The PVC valve will go on the driver side valve cover at the rear of the cover and a hose directly to a large manifold vacuum outlet at the back of the intake manifold or the back of the carburetor . If you do not have a PVC valve already you will have to drill out the valve cover ,off of the car of course ,and get a grommet and PCV valve .It would be easier to get a valve cover that is already set up for a valve .

 

[dennis112]

I would like to add that just drilling an old valve cover may not give the necessary splash shield that prevents excess oil from being drawn into the intake manifold. It is practically mandatory. Either source another valve cover or plan on making a shield. From my experience, the deep pocket grommets are not a good substitute.

 

[Lee317]

Thanks guys. This is helpful. I have a PCV valve already. It goes from the carb manifold to the rear of the passenger side valve cover. But I'm still getting a little blowby from the oil breather cap.

In going to try the procedure that horse sence suggested and I'll post my results.

 

[horse sence]

Once you get the PVC valve and the breather cap hooked up it may help

 

[7991LXnSHO]

I have done this with other cars to keep the engine bay cleaner, and it is a mod well worth doing. I agree with most of what is posted here already. A baffled valve cover, PVC valve and the PVC port on a later or aftermarket carb is the cleanest install. You may have the right place to hook it up if you find a picture or diagram of the California system. Using one of the vent filters that go through the side of your closed breather is another OEM proven way.

Do it neatly and no one thinks it is not stock! On one of my cars I added more than just PCV to. I did not like the noise or look of the cheap chrome open breather. So I put together two OEM filter housings and came up with a stock looking dual snorkel set up. It even uses the temp controlled warm up flaps. Only once has someone comment about not remembering that factory option and asked where I got it.

 

[Lee317]

I think I may have been a bit confusing in my initial explanation. On the passenger side rear valve cover of my '66 289 there is a stock PCV valve connected by a hose to the back of the carb. So the crankcase already has positive crankcase ventilation. The modification I am considering is switching the oil breather cap out with one for a closed system and then drilling a hole in the air cleaner to connect the oil cap to as Horse sense described this in his initial reply to me.

I am just concerned that this may lead to a tremendously dirty and oily air cleaner from.

 

[barnett468]

I think I may have been a bit confusing in my initial explanation. On the passenger side rear valve cover of my '66 289 there is a stock PCV valve connected by a hose to the back of the carb. So the crankcase already has positive crankcase ventilation. The modification I am considering is switching the oil breather cap out with one for a closed system and then drilling a hole in the air cleaner to connect the oil cap to as Horse sense described this in his initial reply to me.

I am just concerned that this may lead to a tremendously dirty and oily air cleaner from.

hello;

well unfortunately you have blow by, so you can let it blow on your engine, let it blow into your air cleaner and engine, or fix the engine.

you could also just run a hose from the new breather cap to the bottom of the engine or rear bumper and dump it on the road and the cars behind you .
.

 

[7991LXnSHO]

GM air filter housings had a clip in plastic filter with filter material inside the housing and a hose connection outside at least the in the early 80's. You might be able to pick your size at Autozone etc. If I picture your idea right, it is just what you need. A little oil on your air filter will not hurt its filtering ability. And I would rather have the messy blow by filtered twice rather than on the outside of the motor, or directly into the intake. It sounds like a good idea to me even after you do a rebuild.

 

[Lee317]

I performed the swap today to a closed crankcase type breather with a hose from the oil cap to the air cleaner. I didn't want to drill into my original, blue, stock air cleaner so I picked up a replacement 1965-1967 stock V8 air cleaner with CA emissions hose attachment on the front as well as a push-on CA emissions oil cap with matching hose connection plus an oil cap to air cleaner hose (matches Ford factory hose with a specific bend to fit between the oil cap and air cleaner perfectly).

Beware, the replacement air cleaner that I got was black (to be painted to match by the buyer) and did not include the hardware to attach the snorkel nor the rubber seals on the cover nor the bottom side for the mating with the carb. I had to pull these items from the factory air cleaner.

All in all it took 10 min to attach. So far so good. Thank you everyone for the suggestions.

 

[horse sence]

Never ever paint an air cleaner filter ,it will plug it up . I restored a 56 Chevy for a friend and the air filter i was able to get was white ,he wanted to use it i a car show so he painted the filter black. As he was driving it started to flood ...bad . The filter being painted could not draw air so it was drawing through the carburetor and sucking gas from the bowl. BAD IDEA

 

[horseballz]

Never ever paint an air cleaner filter ,it will plug it up . I restored a 56 Chevy for a friend and the air filter i was able to get was white ,he wanted to use it i a car show so he painted the filter black. As he was driving it started to flood ...bad . The filter being painted could not draw air so it was drawing through the carburetor and sucking gas from the bowl. BAD IDEA

I think he was not talking about painting the "filter" element itself, but rather painting the metal housing? Although, I think it's not a good idea to paint the inside of the housing, just the outer shell.
Lee, out of curiosity, do you have a performance cam in your engine? Even if you don't, you all should check out the info about PCV systems on this site. Even if you're not thrilled with their product (although it works well, as claimed), there is a lot of good info here:

http://mewagner.com

Just My $.02,
Gene

 

[Lee317]

You are correct, I was talking about painting the air cleaner housing, not the disposable filter on the inside.

The engine in my '66 is stock. I have heard about the $100+ PCVs but for now the closed breather system is working to keep things clean and there is less exhaust coming from under the hood which is also keeping the air inside the car smelling better as well.