bladerunr

iTrader: (14)

I am passing to much oil through the PCV tube even with a catch can. what is the down side of plugging it? what other options do I have? thx

Papasib

Not quite sure, do you really think it can help? try it and let us know.

jeff5347

from my muscle car knowledge a pcv or some type of breather is needed. This is Positive Crankcase Ventalation. Drag carshave the "breathers" connected to the headers and this acts as a vacuum. this helps the rings seat tighter against the cylinder walls and use all the combusted power. You wouldnt do this on a street car as it does suck oil but they dont need to worry about this in a drag car. If you dont have the pcv it can build pressure in the engine and blow oil through seals such as the the valve seals and crank seals. mine loses oil into the catch can to but not enough to worry if you change the oil every 3000 miles.

beefy23b/97

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
he's right don't plug it! oil fumes will build pressure in your crank case and blow seals. Go to the auto parts, buy a breather filter and retro fit it to the hose. This will allow for the gasses to escape but not let any crap back into the oil.

bladerunr

iTrader: (14)

A breather would dump too much oil into the engine compartment. I am getting a lot of oil in my intake manifold. Anybody seen this before?

P. Samson

Covered umpteen times before.......bladerunr.......by design (the PCV system) you will always have some oil in the intake of your car and this means anywhere downstream of the air filter on a stock car. It is just a fact of life, but how much can depend on the engine condition and how much you romp on it, particularly if it's a manual tranny car. What is your oil consumption? The PCV valve and hose carry the breather vapors out of the crankcase into the intake manifold when there is some intake vacuum but at/near WOT when there is low vacuum and the engine is putting out the power, the breather/blowby vapors get dumped out of the crankcase via the crankcase vent hose into the intake duct just downstream from the airfilter. DO NOT block anything off, or use a vent filter if it's a daily driver. Breather/blowby vapors are a filthy pollutant. If the engine oil consumption is reasonable and it has no performance/operating problems and you've got a good PCV valve installed, don't sweat the oil in the intake.

beefy23b/97

A breather doesn't dump any oil into the engine bay. The oil is coming out in as vapor (gas). There is plenty of air current under hood when driving to clear it out. And as far as it polluting. That's the dumbest thing I've ever heard. Our catalytic converters are making carbon monoxide into carbon dioxide. Which current research is showing that Dioxide is more harmful than Monoxide. DEQ my a$$.

P. Samson

beefy23b/97........breather vapors are comprised of very fine oil droplets suspended in the air and the combustion gases that get past the piston rings. Go and search for "oil catch cans" on this forum if you don't think that there is oil in the breather vapors. You should also research PCV systems. Auto engine breather vapors were the first automotive emissions to be controlled by legislation of your federal government for all 1963 and later cars sold in the US just because they are such a bad pollutant. The existing "closed" PCV system is the result of that legislation. Before that, the crankcase vent (very often the vent was integral with the oil filler cap) was open to atmosphere, and you'd see breather vapors (and drops of oil) getting dumped out of the "road draft" tube under the engine and into the atmosphere. I know because I had a 1962 Dodge Dart V8 with such a system. So.......do your research.

beefy23b/97

Uh If you read my earlier post I said the oil is in vapor form, never said it wasn't present at all. Plus your catalytic converter that our fine government said was so badly needed on our cars creates worse pollutants than your engine does regularly. Like I said carbon monoxide is a worse environmental pollutant than carbon dioxide. So our cars are actually polluting worse with a cat on. So following my point the crank case vapors would be less polluting than the amount of CO2 your cat is creating. Do your research. Don't trust everything as fact just cause a government regulates it. Besides the number one green house causing gas present in the atmosphere is water vapor, and you expel it when you breathe along with carbon dioxide. Maybe you should filter that too.

P.S. an independent study out of Australia shows the average house hold dog has a larger carbon footprint than an SUV per annum.

00Lightsout

get a catch can, and stuff it with rough grit steel wool...the steel wool grabs the oil vapors and holds onto them much better than having an open catch can! if you install a catch can be sure to use hosing that is petroleum rated and reinforced so the vacuum your intake creates does not collapse the hose and plug itself....also, I wouldn't recommend a catch can with a breather on the top...the engine needs the vacuum line to the intake to keep it at proper idle.

tha's just my 2 cents

Norm Peterson

As long as the PCV path is not clogged, air flows through the air filter, the breather line, through the crankcase, through the PCV and its hose into the intake manifold. The PCV is intended to be closed at idle (high vacuum) and when the engine is under heavy load (low vacuum). This keeps it from fouling plugs at idle, not sure what the exact reasoning is for WOT.

A PCV can handle small amounts of crankcase pressure (from blowby of combustion products).

Should the PCV become plugged for any reason, or if excessive crankcase pressure/blowby exists, crankcase pressure causes backflow up the breather tube as well as through the PVC (or instead of through the PCV if the PCV is completely plugged).

It's the way the system is supposed to work; either way the oil mist gets burned as part of the normal combustion process.

Replacing the breather tube from the air filter box with a breather cap absolutely will make a small mess given enough time and hard running (or if your engine has significant blowby). The small droplets in an oil mist will collect around the cap. It will still happen even if your valve/cam cover/whatever is baffled to minimize this, the only difference is that it takes a little longer. A properly designed air/oil separator is a better solution but is an extra piece.

I'd try replacing the PCV before doing anything else, as it may be stuck shut or jammed partly open.

I've owned a few older cars, too. Road draft tubes and all.


With respect to "monoxide" vs "dioxide", be careful who you are listening to and be a little suspicious of their agenda. The downstream effects are somewhat different, so a simple comparison is not entirely valid. Best to stay on the topic of PCV anyway.



Norm

jeff5347

Norm. a little off topic.. but you own a 79 Bu.. ahhhh that was my first car and it was awesome. 357..400hp..now a have a 68 camaro. this is the breather system i will be putting on the cam when im able to get the cash to get her completely resto'd..

http://www.popularhotrodding.com/tec...ion/index.html

beefy23b/97

Sorry should prolly go to the General thread to vent about pollution and global warming being BS. We need a rant and raves section!

beefy23b/97

Oh and try using synthetic oils. They have a decreased volatility, and won't have near the burnoff of conventional oils. Amsoil's website says it all, since synthetics are better structured chemically they have less junk to evaporate off when it gets hot. So less fumes will be entering your intake via the PCV.

crazy97

iTrader: (1)

Welcome to the 3.5 V6

crazy97

iTrader: (1)

False. I switched to Amsoil's best stuff, still a quart every 900 miles sucked into the intake.

beefy23b/97

A quart in 900? And amsoil isn't cheap! Just used amsoil for the fiirst time on my last oil change, its been over 1k for me and still reads dead full on my dipstick. I normaly would have added 1/2 qt by now. Dam vq's are so inconsistant.

crazy97

iTrader: (1)

Oops. I meant A HALF a quart every 900 miles. My bad.

Wheelie King

iTrader: (19)

I can't believe someone posted another thread on this subject.

Does anyone have any new tips for improving catch can performance?