T Mack 1 - FSO wrote on 03/25/08 at 17:45:48:Yep leave it in ...
BTW.... you can tell who has worked on old engines and those that haven't ... The days before PCV valves....
That was at the latest early sixties, when most engines still has just blow by tubes, except motorcycles and atv's which kept the simple blow tube into the eighties. The pcv is great, because it allows the crankcase vapors to be sucked out instead of just staying in the engine and creating sludge. That is another reason to get an engine up to temp and keep it there a while, allowing the oil to reach operating temp and vaporizing the volitile junk in it and the moisture then get sucked out and burned. On the Savage there is no pcv because the crank vent is
before the carb, but still in the intake tract. A pcv is used after the carb/throttle body because it is in the portion of the intake that is senitive to vaccum. The pcv has a valve and calibrated spring inside that does'nt allow a huge vaccum loss that would upset the engine. Pcv's and egr's are both good for engines, and to remove either could only lead to decreased engine longevity. There is still even non-detergent oil out there for ppl who have antique vehicles that might be sensitive to modern oils(modern seal material should allow modern oil to be run). Sometimes during an oil change, when the drain plug is still out, I take the vent hose off the head and blow low pressure air thru the sreen, thinking if anything is gumming it up it will be blown out(where? yes back into the engine
). If crankcase pressure is not realsed durning engine operation, oil will begin to leak from the weakest seals, and there will also be excessive oil consumtion past the piston rings. I know this from older engines where a dirt dobber has made a nest in the vent hose, plugging it up.
Some racers put that sort of sreen material in the head where the oil drains back into the crankcase, in case of upper engine failure large chunks of material won't drain back and ruin the bottom end before the engine can be shut down.