Gordonm

Pros and Cons of just venting the engine with 2 breathers or a breather and a PCV valve.

weimer20

PCV- promotes ring sealing, reduces oil burn, evacuates moisture from crankcase, etc. No PCV- don't see any advantage.

bashcraft

I can't think of any reason not to run a PCV.

Bowerss2

you dont need them, i have had cars running solid valve covers for years, no problem. Using the old style intake manifold, with the oil fill tube with the breather in the cap, that is all you need.

the only reason not to run them these days is looks.

in about 3 cars, i have never had a problem with oil burn, rings, and this mysterious "sludge" everyone is so worried about these days. People are worried about water moister as well, i have no idea how it would get in there in the first place.....

SH-60B

The moisture is from the blowby. Water vapor is a byproduct of combustion. Even fresh motors have some blowby.

7T1vette

OK, let's try this.... There is no reason to remove/discard your PCV system if you still have one.

wer2xu

unless you live in the Sahara Desert, or Death Valley, moisture goes right through the carb, and out the exhaust....as evidenced by steam in the exhaust...even those two deserts have a relative humidty in the 20's, so water is everywhere....

gkull

Get rid of PVC

No real performance motor has PVC. It is just a bad deal for lots of reasons.

Oil mist promotes detonation, back of the valve carbon build up, piston top buildup, lower life of plugs

It's a big variable vacuum leak depending on engine vacuum so correct jetting is never as precise. cylinder to cylinder A/F is always off because of the shot of foul air coming through a big 3/8th hole

Twin breathers at a minimum or crank case vacuum pump.

Gordonm

Now that makes sense. I'll try the twin breathers and see how that goes. Are you running a vacuum pump or just breathers.

7T1vette

Don't forget to wash the grime off your engine once a month (minimum) because of the oil mist in the engine compartment.

Gordonm

Maybe I need one of these. An LS1 vacuum pump. The reason I ask this is I'm afraid the PCV valve is creating a vacuum leak and the FI is seeing this as a leak and it is running lean. I am seeing a lean condition under cruise conditions. I am going to try and just plug the port on the throttle body and see if the lean condition goes away.

jnb5101

gordonm
how is that vaccum pump plumbed into the motor? where does the output of the pump go?

Gordonm

Don't know yet. I have heard this is quite a popular vacuum pump and has been done before many times. You can plumb it anywhere the engine can vent. I was thinking at the fuel pump area since I have an electric pump now. You could fab up a cover with a breather tube. This also keeps the top of the engine clean looking. I don't know where the output goes but I can sure find out.

Reggie Dunlop

LTI, L88, LS6, LS7, L46, L78, L87, LS5 and of course the DZ302, Hemis, 440-6, 428 CJ, 429 SCJ, SD455, Ram Air IV, W30, W31, Stage 1-455 - I could probably list a couple dozen factoy cars that used it - from GM, FORD, MOPAR, AMC, etc. Not to mention a few hundred thousand home built hot rods. And I won't take the time to mention the modern ones being this is a C3 board.

This is true, it's just not true that this happens in your PCV equipped motor.


On a closed system (the way it was designed) with the proper valve it is so minuscule it matters not.

The great thing about America is you can ask a question and get different answers from different people with different knowledge and experiences and then pick the answer you wanted to get!

Gordonm

I should make sure that the PCV valve is not causing the lean condition before I do anything. It is always interesting to see the varied opinions/facts that come about.

shafrs3

The EFI should compensate for the PVC vacuum flow if setup correctly.

Ironcross

No problems with my Street cars or Race cars. My opinion right or wrong there is zero octane in oil, keep it in the oil pan not recycle it....

This example has been working since 1970...and no oil outside the breathers either. If your blowing oil, the engine is bad, period...

blow the pictures up, no oil...and at different date periods of pictures

edxaide

What year did they start putting pcv in vettes anyway? thanks for info...Ed

Ironcross

Well your wrong on some of the performance engines. You cannot make a blanket statement that all those engines have PCV valves. Always some specific engines didnt have them as not all those years had provision for them however most did. Those that didn`t used breathers as all the early Vettes did or had draft tubes

Here is my favorite engine in my Cuda and low and behold, No PCV. The 1965 A990 Race Hemi.

PRNDL

I love how passionate folks can get about.... PCV !