Bolw By ???

At full throttle the PCV valve does not work, it only works in vacuum situations like cruising for example. You need good breathers to vent the crankcase pressure at wide open throttle. But if you motor is getting tired and you are starting to get excessive blow-by then you can't hardly have enough breathers. The comression rings control blow-by, they could either be getting worn or when you did your burn out if you rev'd your engine pretty hard you could have broke a ring or two. The correct way to find out whats wrong is to have a leak-down test performed on your motor it will tell right away whats wrong.

Chuck