Need a breather with PCV?

rdorman · #1 (**permalink**) 06-07-2004, 05:56 AM

I was running a PCV in one valve cover and a breather in the other. Even with baffles in the valve cover I would get some oil out of the breather. Not a bunch but enough to leave little pools of oil on the intake. More of a nuisance than a issue.

So I bought a oil filler cap and replaced the valve cover breather. I have not noticed any difference except that no more puddles of oil.

Question is, should I be running a breather with a PCV? Pros and Cons?

Rick

Cobra20646 · #2 (**permalink**) 06-07-2004, 07:55 AM

Rick,

It's my understanding that the system should pull air into the breather cap, down through the head into the lower block, then up through the other head where the vapors are sucked into the intake manifold via the PCV. Without the breather, the system won't function as you won't have the 'cross flow'. I have mine set up this way and don't have any vapor/oil leaving the breather cap.

- Jim -

rdorman · #3 (**permalink**) 06-07-2004, 07:58 AM

Now that I think of it, it may have been the type of breather I was using. It was one of those open K&N breathers that was designed to fit in a round hole and not the twist lock type hole. Perhaps I will go to Ford and pick up a twist lock type breather and try that.
Thanks
Rick

MidOHasp · #4 (**permalink**) 06-07-2004, 08:25 AM

Rick, I've got the twist type lock breather on the driver's side and I have the push in rubber grommet style breather on the passenger side...the kind with the nipple. That nipple has a hose running to the carb for PCV.

They have the black foam inserts in them and I've found that they got soaked with oil and are now dribbling on my valve covers.

I soaked them in lacquer thinner which got a lot of the oil out. They dried out quickly and I probably have another 5-600 miles until they start happening again.

I like the look of the round chrome Ford breathers, but they don't seem to last a real long time.

I was under the impression that the system WOULD work the way you proposed (and tried) but Jim has a good point. Would putting a closed cap on the other bank have the same net effect of plugging the PCV hole on the carb? (just the long way)....

I would like to eliminate the oil splattering that starts every 5-600 miles. I have baffles in my valve covers.

Would like to see more on this topic! BTW, if you didn't read my post on the "coolant plugs" thread, the Evans stuff works like a dream. So does the fan override! SPF 1670 is now a reliable daily driver!

rdorman · #5 (**permalink**) 06-07-2004, 08:42 AM

I did see your update on the REAL coolant

It is nice to see some one do follow up. You see hundreds of threads on problems and recomendations and then they never tell you how it worked out! I to have thought about doing the Evans coolant. Just not yet!
Rick

rdorman · #6 (**permalink**) 06-10-2004, 05:55 AM

OK I did a little research and what I found is that the system does need a fresh air source. There are two basic types of systems when it comes to a fresh air source. They are open and closed. An open system is one that draws air through a vented filler cap. Our typical setup. This works fine except when crankcase vapor becomes excessive and then is forced out of the breather. Hence the little puddles of oil. The closed system draws (or expels) air from the air filter housing. So when the vapor volume is high, it is introduced back into the engine. No more little puddles.

Rick

rdorman · #7 (**permalink**) 06-10-2004, 06:00 AM

For a closed system it appears as though ford racing part number 397-m-6766-d302 (number from jegs site) is the one to use for a twist on breather for a closed system.

I am off to Jegs!

Rick

MidOHasp · #8 (**permalink**) 06-10-2004, 06:09 AM

Rick,

I may want you to pick me up one of those if you would. I'm good for it.

How exactly does it work? Do you have to thread a bung into the air cleaner assy.? Can you keep the basically clean look that we have with our "open" systems?

Just curious...

trularin · #9 (**permalink**) 06-10-2004, 07:26 AM

Rick, if you draw air out of the engine, it has to come from somewhere. Given that, you need to provide a vent for the air to come from, this is the breather.

There is another solution, breath from the air cleaner. If you put a pipe in the base of the airfilter, on the insidewhere the air has already passed through the filter, you can draw air all day long and it will not have debris, particles or oil in it.

This system was used for several years in cars until a seperate breather was install on the outside of the filter element.

If you want to put in a air cleaner pipe, drop me a mail and I'll send you one I have and not used.

Let me know.

rdorman · #10 (**permalink**) 06-10-2004, 09:56 AM

Trularin, that is the type of system I was trying to describe as a closed system.

JP, I will pick you one up. It is just like Trularin described and I was attempting to describe. The part from ford comes as a chrome "breather" that says ford motorsports on it with a nipple. It also comes with a fitting for the air cleaner. Price is a whopping $8.99. If you don't like the look of the hose to the air cleaner you can always get some of the fake AN stainless cover stuff

Rick

rdorman · #11 (**permalink**) 06-10-2004, 09:59 AM

Oh JP. I was reading the description of your system. You do have a PCV valve don''t you? You need one. Not just a open connection to the carb. That will cause a variety of performance issues. I have a 'billet' PCV valve in a grommet on one side connected to the carb base and now will have the 'breather' with a nipple connected to the air cleaner base.
Rick

MidOHasp · #12 (**permalink**) 06-10-2004, 11:06 AM

Rick,

A PCV Valve? A PCVV? That's too many letters together for a Cobra. My honda has VVTLEC, but really...

I don't think I have any valves. Come to think of it, the damn miss started when my dad hooked up the PCV connection we have.

Hopefully we can talk at the OCC show. I'm planning on being there "light rain" or shine, but probably not in a downpour. I'm playing it by ear.

Thanks for picking that up for me. We can look at my engine compartment and play with it. If I need anything else, I will swing thru Jeg's "on my way" home.

JP

rdorman · #13 (**permalink**) 06-10-2004, 01:16 PM

Quote:

Originally posted by MidOHasp

Rick,
I don't think I have any valves. Come to think of it, the damn miss started when my dad hooked up the PCV connection we have.

JP

Yep, that will do it! The valve flows very little at idle and more as vacuum decreases. Properly functioning, you would never know it is there. Of course if you don't have one, it can't function properly now can it! Kind of like a BIG vacuum leak.

I am going to stop over at Jegs after work. Which is about NOW!

Rick