PCV valve VS venting to atmosphere???

Sorry for this rookie question in advance LOL. I recently ordered a new intake manifold form TA Performance and when I was talking to the representative he said I would need a PCV valve. Right now I do not have one. My valve covers are just vented to atmosphere. Do I need to install this PCV valve or just leave it the way it is? Sometimes a little bit of oil comes out of them but it really hasn't been much of a problem. And do I even need to vent both sides?

 

One side for the PCV vent is fine. The PCV valve, however, should connect via a 3/8" hose to the base-plate of your carburetor in order to capture any unburned fuel vapors from your crankcase. The PCV valve is mounted in a hole with a rubber grommet at the rear of the intake manifold.

 

They contaminate the fuel charge without a water/oil separator in line, I usually run one but I prefer vented to a canister or header evac

 

If the heads are vented to atmosphere isn't that venting crankcase pressure? My rig is not a race vehicle by any means. It is a street car.

 

Running without any type of Positive Crankcase Ventilation system also leads to rapid contamination of oil.... which can form (Sludge), trust me I know. That sludge can form in the oil pan as well as on other components such as on the inside of the valve cover breathers and clog them causing unwanted crankcase pressure and oil leaks (as Larry mentioned above). Though it may be overkill for most folks, I just got in this snazzy oil separator (Mann-Hummel ProVent 200) that filters the positive charge entering the vacuum source (virtually eliminating the concern of fuel charge contamination that Ethan posted) as well as it has a return port to send any oil mist that may have been collected back (Filtered) into the sump of the oil pan. I will need to have another fitting welded into my aluminum pan for this return as it should be plumped into the oil pan below the oil level in the sump. And it has a replaceable filter.



Larry

 

Of even more concern to many is it keeps the under hood/area/compartment much cleaner. NO oil filled mist being emitted.

 

This is good info as I too vent my covers like OP.

So is a second breather needed or is it cool to have the PCV on one valve cover and a breather on the other side enough? And where exactly is the other end of PCV hose connecting too?

Thanks
Jeff

 

Got it. Thanks, Larry.

 

You are a lifesaver. Thank you for that post as I'm installing a SP-1 right now¡!!!!!!!!!!!!!!!!!!!!!!!!!!!! That clears everything up!

 

The PCV port was plugged when I bought the car. Apparently someone thought it was not necessary. I'm a motorcycle guy delving into the world of old muscle cars and I'll tell you what, such a learning curve. I just got done installing bags on this car and that was another pain in the @$$. I'll have videos on that in the next few days. I just want to thank all of you for helping me out. This forum is a real blessing.

 

OK, you have the suction side of the PCV system addressed. But you need to make sure that you have filtered air entering the crankcase, so there should be a filter somewhere, not some vented cap on a valve cover that can let dirt into your system. That usually comes from a hose that connects to the side of the air cleaner, with a filter. But I'm a little rusty on the '67 cars, so someone can chime in on that. I know how Chevrolet did it, as I worked on them back in the day. The different makes addressed it differently.

 

hmm...well I will have to look at that. Both my valve cover caps have filters built into them. Is that not good enough filtration? It is basically foam inside of them...

 

Yes, that's fine.

Larry

 

Thanks again for the help. I got the intake manifold installed and all seems well for the most part. Engine doesn't seem to be running perfectly but I think it is because I need to reset the Holley Terminator EFI and have it go through the learn sequence again. I have to go through the manual or call Holley and see what is recommended after changing intake manifolds.

 

Very nice engine compartment!

 

Oh well thank you! I'm still working on cleaning it up. I bought some new battery terminals that integrate all the power wiring into a neat package. A bit more cable wrap needs to be installed but it's a hobby and a work in progress as usual lol!