Sea Foam - yes, no ?

[silicon212]

There'd better be a valve. The pipe you are talking about is the breather - this connects to the side of the air cleaner. On the opposite valve cover toward the front, there should be a metal thing that a vacuum line attaches to, which in turn attaches to a point at the front of the carb. That metal thing is your PCV valve.

[Blue Bowtie]

Originally Posted by GreyGoose006

i know that in my car, the pcv is simply a tube connecting the aircleaner to the valve covers.
there is no actual valve, and i am pretty sure that vacuum from the engine wont make it to the pcv tube.

The tube you are describing is the CCV, not the PCV. The crankcase vent simply supplies cleaned, fresh air to the engine so the CV can draw it out. It is routed to the breather or TB so that under heavy load, and blowby gasses reversing through the CCV are drawn into the engine and burned rather than being vented to atmosphere.

If the engine lacks a functioning PCV, there's little wonder that the oil gets dirty so quickly, and that you would be compelled to run some snake-oil crap like SeaFoam through it to try to clean it up.

Look for this label under your hood, and make sure everything is connected as indicated:

[GreyGoose006]

well i am pretty sure that i only have the CCV then
where does the PCV connect to the aircleaner?

working from memory here, i am pretty sure that the only vacuum line going to the aircleaner is teh one that actuates the little butterfly valve that sucks hot air off the manifold.

[Blue Bowtie]

There should be only one small (about 5/32") vacuum line from the carburetor (on the 'B' port in the diagram) connected to the THERMAC valve on the underside of the air cleaner.

There should also be a large (about 5/8") hose from the breather filter in the perimeter of the air cleaner to one of the rocker covers. That is not a vacuum hose, but merely a fresh, filtered air supply to the crankcase vent (CCV), and it is not shown in the diagram.

There should be a PCV valve and larger (about 3/8") hose from the opposite rocker cover connected to the large vacuum port near the bottom of the carburetor, usually at the front of the carb base, but possibly at the rear. That would be the 'L' port in the diagram.

If the engine has aftermarket rocker covers, there may not be a provision for the CCV, but apparently from your description the hole there was used for the CCV instead of the PCV valve. Do you have a photo?

[GreyGoose006]

not really, but i can tell you how my lines work.
there is one going to the themac thing that you described, and one going from the thermac thing to the "nozzle" of the air cleaner, that actuates a butterfly valve.

i certainly havent changed any of the emissions stuff, and the previous owner was an 80 yr old that had the carb tuned so that it wouldnt drive over 70 without starving itself of fuel in the interest of saving fuel and stuff.

i'm guessing that it is all intact

[silicon212]

Originally Posted by GreyGoose006

not really, but i can tell you how my lines work.
there is one going to the themac thing that you described, and one going from the thermac thing to the "nozzle" of the air cleaner, that actuates a butterfly valve.

i certainly havent changed any of the emissions stuff, and the previous owner was an 80 yr old that had the carb tuned so that it wouldnt drive over 70 without starving itself of fuel in the interest of saving fuel and stuff.

i'm guessing that it is all intact

[PeteA216]

Silicon, it looks like something is holding up your CCV. In my Caprice, back when it had it it just hung there above the water pump being held by nothing but the vacuum hoses.

[silicon212]

CCV? You mean purge valve? Yes, it's on a bracket bolted to the alternator bracket.

I just got to thinking about something. It seems that I am the only one who has done a 305-to-350 swap and retained the OBD system. Most of that has to do with the way I like how it runs via computer control - another part of me likes the car to resemble stock as much as possible (even though there's some chocolate underneath that vanilla exterior). Kind of what one might refer to as a "sleeper". Everything you see on it came from that old 305.

[PeteA216]

I like the sleeper look to a car. This is why I'm basically keeping the exterior stock. Yesterday I got the car inspected, and the mechanic made me laugh. You've seen the pictures of my engine, so you'll know why this happened. The guy goes out to the parking lot and snickers at my car. Starts it up, brings it into the shop (the exhaust sounds almost stock). Pops the hood, lifts it and I hear "Holy $hit!" The reaction is exactly what I was going for. I can imagine you though. Looking completely stock in and out, but really giving other cars a run for their money.

[Blue Bowtie]

Originally Posted by silicon212

CCV? You mean purge valve? Yes, it's on a bracket bolted to the alternator bracket.

I just got to thinking about something. It seems that I am the only one who has done a 305-to-350 swap and retained the OBD system. Most of that has to do with the way I like how it runs via computer control...

I've gone the same route, but actually added "smog crap" to make it run better. For a recent EFI conversion on a Chevelle, I pulled an almost brand new Edelbrock clone of a Carter AFB and Performer RPM intake, installed an EFI intake and system, and dropped 0.7+ in the ET (actually, closer to 8/10). Same short block, same cam, same exhaust, etcetera. Add some "smog crap" and an ECM and drop ET, increase trap speed, and drastically increase MPG while street driving.

Yeah, that smog stuff is "crap" without a doubt.