-------------- Original message from David Leonard <wdleonard@gmail.com>: --------------

On Fri, Jul 3, 2009 at 8:54 AM, Ken Welter <rotarycoot.ken@gmail.com> wrote:

My engine is a 1986 13B with 88 hrs since remanufacture.
I fly a Zenair Zenith with a cogbelt PSRU and a Warp Drive 3-blades prop
and  this engine never runs above 5700 rpm
When I installed this engine in my Zenith I removed the metering oil
pump and have been using two stroke injection oil mixed in the
automobile  fuel  ( 87 octane gasoline)
At first I used a volume mix of 128:1 gas to oil and soon noticed an
increase of engine lubricating oil volume in the oil pan
I have gradually reduced the volume mix of gas to oil to 140:1 but there
is still a slight increase of engine lubricating oil in the pan.
Also a local mechanic has mentionned that the two stroke injection oil
is degrading the 20W-50 engine oil.
How much can I reduce the volume mix of gas to oil ?
Please advise

Yvon

  Yes you will get an oil accumulation and there is no getting around it, I would mix at no less than 100 to 1 ratio, I have seen no problems with the 2-stroke oil mixing in the case oil and only change my oil about every 200 hrs.

 Ken

I would ditto what Ken said.  I tried reducing the amount of 2 stroke until there was minimal accumulation, but I ended up with a stuck side seal and had to do a re-build.  Could have been from detonation or lack of oil, but I decided to stop taking chances.  The dilution still works out to be just a couple of quarts in a 7 quart system, so the real engine oil is still around for most of the work.  I use Mobile 1 (or any full synthetic) - thinking that it will be more stable for the gear box lube.
--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net