Turrbie@aol.com wrote:

 Bill Freeman wrote:
 >
 > Paul,
 >
 > Why not build a simple venturi system with an adjustable
 > (reaplaceable) orifice which feeds the oil into the fuel upstream
 > of the fuel injection.  Start a little big and watch the usage rate
 > and adjust the orifice size downward until it feeds the
 > correct ratio.  The use of synthetic would help avoid
 > the problem of variable viscosity (with temp) of the oil causing
 > variable mixing ratio.
 >
 > This is how your hose-end yard sprayer works and it is
 > easily adjustable, and seems to work well.
 >
 > The only downside is running out of oil in the tank would
 > fry the motor.
 >
 > Bill

The convenience of having oil injection is great, but in an aircraft
conversion, it would seem to be an added risk. Consider a failure in the
system would toast the apex seals and there's still no standing, stopping or
parking allowed on the clouds. With premix, the job is already done and you
can forget about it.

A compromise could be a calibrated hand pump mounted in the cockpit that is
connected to an oil tank and the fuel tanks. After fueling, you simply stroke
the pump X times for the amount of fuel taken on and your done. Unless the
tanks were bone dry, the premixed fuel already in the header tank should give
the fresh oil time to mix by natural agitation before reaching the engine.
Bruce Turrentine

Besides.. if you kick the rudder a couple of times the fuel is thrown
violenty from side to side in the tanks throughly mixing the oil
with the fuel.

Paul
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org