Am I the only one who has tried this?
stingray719,
I try to avoid from posting on these threads, as I don't want to come off as dismissing your idea.
I have done extensive testing on this though and feel that I must chime in so that you don't run the risk of damaging your engine.
The crankcase breather must flow both directions. At idle the breather flow pulsates and as rpm/engine load increases the flow changes to positive air flow out the breather tube. This is why check valves are generally a bad idea as they typically will flow only in one direction.
The volume of air exiting the breather tube at wide open throttle is very high. This is why the diameter of the breather hose is so large. The air pressure in the oil tank must remain near 0 psi at all times! If pressure is allowed to build up, then the savage rate of the oil pump is effected. PCV valves do not have enough flow volume to allow the oil tank to maintain 0 psi at wide open throttle. When this happens the oil level in tank can drop (due to the poor savage rate) causing an oil supply issue when you need it the most.
Check balls, this is a bad one. Snowmobiles bounce around alot. As the sled is bouncing around, its causing the check ball to move. In this case you have a prefect storm brewing, a very high breather flow rate (due to being in the throttle) and a bouncing check ball. Once the moving check ball gets closer to the seat, the high breather flow rate will lock the ball on to its seat and the pressure in the crankcase/oil tank keeps building higher and higher until somthing lets go. Usually it blows out the cam plug seals, but I've heard stories of blown oil tanks and hoses before also.
Budget is budget and I get that. Some people don't want a roll-over kit and that's fine too. If I was low on funds or didn't want a ROV kit, I probably would do some type bottle/hose set-up. They can be kind of a hassle at times due to draining the oil out of the bottle and back into the oil tank. But at least it would have a proper flow rate.
However after what I have seen testing ROV/breather systems and how quickly the pressure can build up, I would never ever install any kind of a check ball or jiggle valve. The oiling system is critical on a four stroke and its just not worth the risk!
Again I'm not trying be an a$$, its just that I feel that I need to say something to try and prevent a really big problem down the road.
Bill
