Oil on my belly..

[ccsmith51]

Well, not my belly, as large as it may be, but the belly of my RV-4.

It seems that after every flight I have some oil on the belly from the breather hose. It comes straight from the top of the crankcase and I have it cut flush with the bottom of the fuselage, next to the firewall.

I thought that it might be from me regularly doing rolls when I fly. So today I made a 0.47 flight in the calmest air I think I have ever flown in. And I made no abrupt maneuvers, no rolls, nothing but the kind of flying I would do if I was taking an 85 year old grandmother up for her first flight in a light plane.

But when I got back down to the hangar I checked, and there was oil on the belly, from the breather.

Is this normal? If so, why? Can I stop it? O-360 and I usually run 6 - 6.5 qts.

Thanks,

[LifeofReiley]

http://antisplataero.com/Videos.html

[ccsmith51]

Thanks, Reiley. I have their oil filter and axel nut wrenches and they are great products. I'll get in touch with Allan to discuss a separator for my plane.

[AltonD]

A suggestion:the flat breather tube is creating a venturi and drawing a vacuum on your crankcase. Bevil the tube such that it is slightly angled toward the front of the plane.

[ccsmith51]

Thanks Alton. I'll give that a try!

[LifeofReiley]

Originally Posted by AltonD

A suggestion:the flat breather tube is creating a venturi and drawing a vacuum on your crankcase. Bevil the tube such that it is slightly angled toward the front of the plane.

This will help for sure... there will still be some oil on the belly.

[Ron Lee]

Alton, is that cut such the breather is slightly pressurized (air goes into it)?

[AltonD]

Yep. No ill effect. It is more of no vacuum sucking the oil mist out of the crankcase.

[LifeofReiley]

In the Van's Kit the tube is bent slightly forward and directed to the pilot side exhaust pipe with a couple of whistle slots cut into the tube.

[Pat Stewart]

Alton is spot on. That should fix your problem however a little oil is normal.