401 Valve Cover Breather - 2 ok???

[Guest 1965cat]

I have a newly-rebuilt 401 (.030 over) stock cam, Carter AFB 3921, Non-ac, Turbine 400... I am in the final stages of adding the valve covers and misc brackets,etc... The stock left side valve cover had a rubber plug on the top end over the #2 cylinder and their was an oil breather in the oil cap. Can I add another oil breather in that valve cover using the hole the rubber plug covered along with the breather in the oil cap? I don't understand the reason for an oil breather in the first place and was wondering if two were better or really had no effect on the engine??? <P>Thanks,<P>Mark<BR>BCA# 372362

[Guest]

The extra breather won't hurt anything. Their purpose is to let blow by gasses escape from the engine. If you had a PCV system hooked up it would suck that air back into the engine instead of venting it to the atmosphere. In fact if you don't mind deviating from stock it will keep the inside of the engine cleaner (along with the ozone) if you install a PCV system.<P>F.Y.I. A quick way to check the blowby on a used car is to pull off one of those breather caps and see if you can feel air blowing out of the hole. If you can it means the rings are bad.<P>Tomsriv<BR>71 Riv