PCV Valves

[Ron61]

Race car or not, I think the PCV is beneficial. Your engine set up sounds more race oriented than street, but so is the BB in my 69 NASCAR Cobra and it has a PCV from the factory. One line goes into a fitting behind and below the carb, and the other comes off the cap that I take off to put oil in and goes to the air cleaner. If you have a spacer under the carb and it has no place to hook your line, you can drill it and put in a fitting.

Ron

[vettestr]

I would avoid using a T fitting on the port used for a power brake vac canister. The reason I suggest this be avoided is the oil film or even a little oil in a low spot of the feed hose that can be found after a few hundred miles after install. Probably others on CC that can speak to this better but that is my reasoning after inspection over the years not to mention if a PCV fails open it could also lower available brake source vac.

Put connection as close to carb base on manifold as possible and avoid connection on a single cylinder runner (often a plug in many manifolds 2 to 3 inches from #8 cyl to head gasket). All things are possible but a proper install will not affect carb jetting or lean 1 cyl. out or change RPM when you block PCV with your thumb at idle. If it does something is wrong with the install or system.

[BDR561]

I have a 1" spacer that I could use (possible hood clearance issues) that I eliminated during break in and for clearance concerns. Makes sence to use it and tap for PCV.

I will do it at the same time I start to tune the A/F ratio

[Bob In Ct]

As Elmer Fudd said "be vewy wewy caweful". PCV valves allow (extra) air to enter into the intake manifold. This causes the air/fuel mixture to lean-out. Don't just assume that all PCV valves are created equal. The valve on your 74 Fairmont was designed to be there. You may cook your valves and pistons in an effort to circulate some fresh air through your crankcase.

The PCV valve was one of the first anti pollution devices. It was not invented to reduce pressure or circulate lots of fresh air through your crankcase as some have said. It was designed to burn crankcase gases that at the time were just vented to the street through a tube under the car. Believe me, I was there.

Bob

[nevermind65]

Well, I did 2 things. First, somebody had K & N breather filters on the valve covers. They came off and hit the trash and some chrome breathers were installed. That helped quite a bit. Next, I drilled the valve cover for the PCV valve. That took care of everything else. No oil puking out from the filters, and no oil smell from the blow-by. I did have to richen it up a bit as Bob stated. As for the drop in vacuum, I see nothing.