I read somewhere that a breather for your valve covers would help give you a few horses.What is the true benefit of these breather elements?

 

it just vents crankcase pressure i dont see why that would matter

 

I did't think that it really matter because it is not a subjet talked about too regulary. Thanks for the imput.

 

If you put a filter in the valve cover, and remove the PCV hose to the air cleaner, it can make a car run better.

It might run better if your engine is subject to blow-by; meaning, oil is making it past the PCV valve, up the hose, and into your intake causing havoc with the mixture.

I worked on a buddies truck the other day, and when we removed the carb, The gasket was soaked with oil. There was LOTS of oil making it past the PCV valve and into the intake. We replaced the seal, plugged the port in the intake, and put a valve cover breather on. It runs much smoother now.

Other then that, I can't think of much else it might do for you. The only other factor I can see it changing, is the vaccuum the PCV hose creates in the crankcase. Some say this vaccumm helps the oil seals (rear main, crank, oilpan) from leaking; but both of my vehicles (SBCs) have valve cover breathers and I've never had an issue.

My 2 cents,
Thomas.