Here's a thought...try running with two breathers and NO PCV valve. In the old days, engines used a "road draft tube", but you can get away with running two quality breathers and no PCV....you may have to readjust your idle mixture screws, and you'll have to watch for oil leaking out of the breathers if there aren't baffles in the valve covers. I ran my 318 Mopar like that with no problems, and no oil leakage. Worth a shot.
Your car is old enough that the Smog Police won't cry "foul" if you don't run a PCV! Actually, in engines where high revs are seen on a regualr basis and the oil pressure is high...it's not that uncommon for them to suck oil through the PCV hose. I would just run breathers, unless you have a real need for the PCV. I run the PCV when I can...but I've run just as many engines without one, too. Just give it a try and see if your plug fouling problem goes away. If you run breathers only, and you're STILL fouling plugs...then you have an internal engine problem.
For the PCV - I'm not a lot of help here, but have you thought of switching to a different PCV valve - they have different ratings. Maybe yours is too free flowing - just a stab in the dark. Also, what kind of baffles in your valve covers? Just a single sheet-metal plate? Try closing it off with a more closed piece of sheet-metal - in other words, make it harder for oil to get there. Don't use steel wool or steel "scrubby" pads. For the black smoke - is it vacuum or mechanical secondary? It sounds like your secondaries are too rich and/or are opening too quickly. There are a couple of bad ideas that have been bandied about by big name car magazines as the way to make your Holley run better - one is to put a screw in the secondary slip linkage (vac sec carbs) to make it mechanical & the other is to take the check ball out of the vacuum diaphragm housing. Both of these are totally unnecessary on the street and will give the symptoms you describe. If you've got mech sec. - try jetting them down and/or changing squirter size. If you've got vac sec - make sure the check ball is in the vacuum chamber & try a stiffer secondary spring. It could just be opening too soon, the engine can't quite use all that gas yet, & you get the black smoke Finally, it is possible your primary accelerator pump shot is too much, too large, or too late. Check you've got a stock orange cam, screw in #1 hole, and about 25-27 squirter for a stock 289. Really shouldn't need anything else. Also make sure your pump arm is adjusted properly - you want it to move immediately, but at WOT, you want there to be about another 0.020" for the pump arm to go so you don't bend things. Good Luck!
The PCV valve is the part of a closed crankcase SYSTEM that operates at IDLE. The part that works at speed is the vent hose that goes directly from some area open to the crankcase, usually a valve cover because it's easy to do, to the INTAKE of the carburetor, usually in the aircleaner base, inside the air filter area. They usually have their own sponge-like filter commonly called a "bowtie" that collect the liquids. You need both these parts, the PCV valve and hose and the crankcase vent hose, for it to work correctly. Check out where these parts go on a '70s car and try to duplicate the function if not the location. You could also have some valve seals that aren't stopping the oil from being sucked by the rear valve stems, and/or your oil is too thick? and not returning to the crankcase fast enough. The rear two cylinders are at the low point if the oil is filling up on top. The PCV valve does NOT work at WOThrottle. That is the job of the other, open vent that should go to the carb intake, inside the airfilter element so the carb will be sucking the fumes into the engine.
Morticia Adams? Personally, Dr J...I thought she was kinda hot, too...but Lilly Munster had a better rack!
There is a balance between Crankcase Pressure and Pulling too much vacuum on your crank case. The oil is in a mist form and it sounds like you are pulling too much. At 7hg you will actually pull oil out of your crank case. Route your hose some where else. Engine ventilation is a big deal and will rob you of horsepower. The pcv was intended to pull gases from the crank case not oil.
My view on what's been said... PCV is there to suck out any vapors in the crankcase. If there are heavy oil vapors present, you will get oil in the hose, all the way to the manifold. PCV works at high vacuum, both at idle and cruise. When you accelerate, vacuum drops and the PCV valve closes; when you are at idle or cruise, vacuum is high and the valve opens. The other hose to the air cleaner (or just a breather) is an "intake" only and allows filtered air into the engine. The old road draft tubes are cut at an angle and placed in an area of high air flow, creating a vacuum on the tube, sucking out any vapors. My guess is that your rings haven't seated which will cause blowby and increased oil vapor. Also it can suck oil into the combustion chamber on a hard deceleration. The main cause of start up smoke is bad valve seals or loose guides. Did you use the little condom when you installed the seals? Now is the time when the ASE guys tell me what I got wrong Chris
A go/no-go test would be running a compression test dry, then wet to give you an idea if your rings are leaking. A leakdown test would do about the same but it may be harder to pinpoint a ring or valve leak. Chris
Hey Chris it totally slipped my mind been real busy and off the com but you still got that torque convertor for a th350? pm me your number again if you do.
Nah, Burndup came and bought the whole trans. He thought it may be a PG but I never heard any follow up. I don't know my Chevy stuff from a hole in the ground. Chris
What kind of opil pan are you running and how much oil are you running in it? If you are running an aftermarket pan that holds 8 qts for example. It will just create more windage in the crankcase and more oil will keep getting sloshed around in te crankcase. This would cause more airerated oil or oil vapor, to reach everywhere in the engine. Shawn
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