With a system pcv valve connected valve cover to the air filter.
Question: What do guys do when they changes for a chrome model filter like K & N which has no output for pcv ?

 

There are fittings available for that, that you can install in just about any flat-base breather.

 

Yes, but they will not be connected to the new air filter. And it can create problems!

 

You either go to a breather or run it into the base of the aircleaner.

 

A breather can it replace a pcv ?

 

Watch this video...see if that helps.

https://www.classiccarrestorationclu...02&vsoid=A6202

 

Used to be pretty common, but depending on blowby etc, you might be able to stand it or you might not.

Every time i have run a breather on an engine i get this overly fuelly/oily smell. I might be oversensitive to it but its not great. Old school motors had the little dump tube that ran down to the bottom of the car - super green solution there... I run the breather side to a dodgy'd up fitting on the base of the air cleaner for fresh air in.

I dont run a pcv valve on the other end. Mine goes from the drivers side hole, into an oil catch can full of stainless steel wool (works suprisingly well) and with the hose pushing the blowby towards the bottom of the catch, then out into one of the ports at the base of the carb below the blades. Works pretty well.

 

and i have pretty much no oil sludge buildup before anyone chimes in... :P

 

I'll try to explain this very simply. You want both a PCV valve (in a valve cover) and a breather connected to the base of the air cleaner (from the other valve cover). When manifold vacuum is high (idle, part throttle) the PCV valve is sucking vapors out of your crankcase, and fresh air enters through the breather in the air cleaner. Things are reversed when the manifold vacuum is low (mid to WOT). Under this condition there is very little vacuum at the PCV valve, but there is a huge vacuum through the carb, which is where your breather is. Vapors are now sucked into the engine through that breather.
This setup makes sure your crankcase is being vented at all times, and not puking blowby all over your expensive valve covers, or on the ground. Best of both worlds.

 

The breather doesn't have to be connected to anything. But it is important to run a breather on one side and the pcv on the other.

You can also connect your pcv to a port on the intake or carb.