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Do you have an oil/air = separator=20 returning oil to the sump? If not, I suspect the "oil usage" you = are=20 seeing may just be oil lost in the blowby. In my early days with = plugs up=20 (before I built a new sump), I would get foaming oil out the dip stick = when I=20 exceeded 5000 rpm so I built an air/oil separator. Later I = discovered that=20 with the new sump keeping the oil level in the block next to zero = eliminated the=20 foaming. However, I can imagine that at 7000 rpm the oil mist and = foaming=20 as the cooling oil pours (or is slung) from the rotors probably suspends = a lot=20 of oil in the air which could get blow out.

FWIW

This=20 is interesting. When I was flying the rev-1 version, I started = with just a=20 small on the dipstick vent. This was just one of those old PVC air = filters=20 that I picked up at an auto parts place. You could see that it got = misted=20 with oil, and accumulated a few drops in the bottom, but that was about=20 it. Eventually, I got around to installing a vent line that ran = down to=20 the exit of the cowl, which worked fine for a while. =

After=20 one particular flight, I noticed that the belly was coated with = oil, all=20 the way back to the tailwheel. I thought it was due to the = fact that=20 I ran the engine harder than usual, and did a little more maneuvering on = that=20 flight, and I'm sure those things were a factor. The real culprit = seemed=20 to be the placement of the vent tube exit. I had changed = something=20 prior to the oily flight, and had to reposition the vent line. = It's new=20 position seemed to be in a location that must have caused a suction = on the=20 tube, which helped the oil escape.

Next,=20 I used a normal size line from the dipstick vent, which is inserted in a = larger=20 diameter clear hose. This is a very loose fit, to allow air to = vent=20 between the tubes. The bottom of the clear tube has a valve, which = stays=20 closed in flight. This allows me to capture, and monitor the = oil=20 loss. I kept this arrangement in the rev-2 configuration, = primarily to=20 keep from dumping oil on the hot = muffler.

I have=20 suspected that running the oil level on the high side was also part of = the cause=20 in loosing oil from the vent. That's one of the reasons I = wish I had=20 extended my oil pickup tube to make up for the engine mount = plate. =20 Hey Fred, = there's another=20 product you can sell. It would be easy to make a spacer to lower = the oil=20 pickup, and supply it with longer bolts.

Cheers,

Rusty=20 (company van being picked up by the fleet dept=20 today)

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