PCV system help

Previous owner modified PCV system on my 1976 CJ5 258. Anyone have photos or know of a good site that shows how a stock system is installed. Thanks!

 

I don't have any pics of mine, but I can give you some help.

The system is pretty straight forward.
You have an air intake hole on the valve cover, and a PCV hole on the other end of the valve cover.
Now, which hole you choose for each doesn't really matter that much.
Mine has the breather in front and the PCV valve in the back.
(I've seen as many the other way though)

For the breather you have two choices (often dictated by the eco laws where you live).
Technically it should draw air through a hose connected to the air cleaner above the carburetor.
My hose was cracked and broken, so I purchased an "oil breather" that sticks in the hole and has its own filter w/ matching grommet.
The PCV valve can be purchased at your FLAPS w/ new grommet. It should be connected via a vacuum hose to the base of your carburetor, or possibly some other source of non-ported vacuum on your intake manifold.

The purpose of the system is to draw fresh filtered air into the valve cover, and suck the blow-by gas that would otherwise be trapped in there back into the combustion chamber. This serves to reduce pollution and just as importantly, it keeps the nasties from condensing and mixing with the motor oil, which would foul your oil and harm your engine over time.

 

I stuck vents in both of the valve covers on my SBC. Since it's V8 there is one hole in each valve cover. I didn't realize there is a function of the PCV to circulate air through the crankcase/valve cover.

 

Yep, a lot of folks think they can just cut out the system if their local laws don't enforce the system. But you'll end up hurting your engine. It really helps to the have the vacuum source on your pcv valve, it actively pulls the nasty vapors out of the engine and helps keep your oil cleaner.
You should also inspect your PCV every so often, pull it out, and run some carb cleaner through it to make sure the valve is clean and functioning properly. The valve should rattle when you shake it.

 

Looking over my PCV lines and emissions stuff as well, came across this pic:

http://www.geocities.com/cantwait_forviolence/library_pages/pcv_system.html

There is some other decent reference materials on that site as well.

 

It seems I need to restore mine as well. Anybody know where to get a stock air cleaner for a '73? It doesn't matter to me whether it's new, old, NOS, or whatever as long as it's not ripped to pieces like my inherited parts jeep. I can't find one on the internet at all. Any suggestions would be welcome.

I also need to replumb the vapor canister; that line is snipped too. I think the 1973 or 1983 Pontiac Bonneville can looks like it will be an easy fit.

 

What kind of carburetor do you have?
There were several engines and carburetors used in 73.

You might check out summitracing.com for a replacement air cleaner.
I bought one of their store brand "chrome" air cleaners and it fits great.
You need to figure out how big the air horn on your carb is though.