Concerning the oil breather hose which connects to the Savage airbox...some owners remove the airbox and connect a K&N type filter to the end of the breather hose.  Does the crankcase breather system on the Savage require evacuation to properly remove the oil fumes/ pressure and is that part of the reason the breather hose is placed in the airbox?  I've heard of automobile engine crankcase breather hoses being removed from the intake manifold and routed out to the air, causing subsequent pressure build up in the crankcase pushing gaskets out of place.  Could the Savage also see this effect by removing the crankcase breather hose from the vacuum effect of the airbox?

Thank you for your reply but this doesn't answer the question as to  whether or not the Savage crankcase system is closed and depends on evacuation for proper breathing.  If it does, then venting the breather hose out of the vacuum assistance of the airbox will cause pressure build up in the crankcase (as a result of the up and down motion of the piston) and therefore possible pushing out of gaskets.  This sometimes happens in auto engines when you remove the crankcase oil breather hose from the intake manifold or air cleaner and vent it to the air, in an attempt to keep oil fumes out of the intake system.

My first car was a 1937 Plymouth coupe, which I bought in 1963.  I've owned around 30 cars since then, and no one ever works on my vehicles except me.  The majority of today's cars have a closed crankcase requiring a vacuum source to suck out the crankcase fumes and an input source to re-supply the air to the evacuated crankcase.  Volvos do this among many, many other cars and if this vacuum source is removed, crankcase pressure will blow the rear main oil seal out enough to cause a serious oil leak and ruination of the seal.  I saw that happen to a friend's Volvo.  My question was if anyone knew whether or not the Savage had a closed system requiring evacuation, something which is commonplace in California emissions spec. internal combustion engines.  The answer to this is to find out whether or not there is an input air source anywhere in the crankcase in addition to the breather hose attached to the vacuum effect of the airbox.  If the oil breather hose is the only vent in the crankcase, then this engine is a simple puffer, just like about 30 years of Chevy engines that had no more than a breather pipe going out of the crankcase behind the engine.  If it is a closed system, then those people who route their breather hose to the air might incur a similar problem like the  Volvo had.

The way I understand it, PVC's are one way check valves to prevent backfires from blowing off the oil pan.

And if I remember correctly, PVC stands for positive crankcase ventilation.  The check valve kept just enough restriction on the vent line to the carb to prevent negative pressure.

?tahw