How bad is mild blowby that is in the form of mild intermittent smoke out of an open valve cover breather??? It doesn't puff out smoke all the time and is very mild when it does. I'm trying to gain an understanding if the blowby is costing me fuel mileage, power, etc. I have a pcv routed to the base of the carb, and an open breather on the opposite valve cover, and both covers have baffles.

Again, it doesn't appear to be much. Any product I could try to help elimate the blowby completely? Swith to synthetic oil help?.....Thanks