I have tried many ways of venting the crankcase on my saito 4 stroke. I now have the line running to the back just past the cockpit and it is still extremely messy. Can I put in a system like this and just change the cotton or papertowel pieces in it every couple of flights? It would not add weight that would be anything critical.
Thanks for any input,

JW:

It's been done, doesn't hurt a thing, and works well for the vented oil. But there's still the oil from the exhaust.

Bill.

I don't think changing the absorbtion material "every couple of flights" is going to cut it... I'm thinking it will be more like every flight...

You could route the case vent to the intake of your engine... that way the oil would go out the exhaust...

JW:

Another thing to consider. If your engine is low time, the ring might not be fully seated, the amount of oil vented will decrease as it does. On the other hand, if the engine is high time, specially if you have dusty air, the ring might be just about used up.

Bill.

Certainly doesn’t cost much to experiment with the idea. One of my friends did and he eventually removed the line to the intake. The conclusion was that a droplet of oil was occasionally released at times that would put out the fire. A big drop of oil during landing and after extended low speed operation might not help the glow plug stay lit. Try the idea. Maybe your results will be better.

Bill S

Newer Magnums and I believe OS 4 strokes have the vent plumbed into the intake... The Magnum's run just fine that way... Biggest problem is trying to get afterun oil into the crankcase if you have the engine cowled in.

On my latest plane I just ran a pushrod tube through the airframe. The oil drips out the back like a full scale Extra.

David

Thanks, everyone for the inputs, I will try them all - does not hurt. You know as well as I do that the oil cleanup is a big pain. It seems at times, that their is more oil from the crankcase mess than from the exhaust. Yet another reason I REALLY like bigger GAS engines now.

@William Robison - Long time running the engine.

Would running the crankase vent back into the intake act as if running a higher oil / less nitro content fuel. thus needing to richen the fuel flow so as not to starve the engine for fuel?? I may be way off with that question.

Jeff

Jeff:

You can run the vent back to the intake, I wouldn't change the oil %. It should not affect the mixture any amount, as the vented gases supposedly have all the free oxygen and fuel already burned. this will devrease your power though, by the amount the fresh air/fuel mixture is displaced with "Stack" gas. My opinion much better to run it into the exhaust, if there is a choice.

A new ring is an easy job in a Saito.

Bill.

When one of the popular maginzines ran a engine test on the then new OS FS91 Surpass II, They disconnected the line from the intake and plugged the intake. It made no difference in power.

Enjoy,

Jim

I plugged the intake on my Mag .90 mainly so I could run the vent tube out the bottom and oil the bearings at the end of the day... I noticed no change in rpm or transition... Seems to run great both ways...