I would say that it
is OK for them to be open to the atmosphere. The reason to connect them
to the manifold is to get filtered air, and to modulate the differential
pressure across the valve. At low throttle there would be low pressure in both
manifold and rotor housing. I have no idea of the full story of the pressure
dynamics over the throttle range.
If the vacuum line is
disconnected, the oil being pumped into the rotor housing drop by drop is not
spread cross wise along the apex seal. Therefore, the oil will do next to
nothing in regard to cooling or lubricating the apex seal.
Based on experience
of others, this appears to be an overstatement. Rotories have run
thousands of hours with no air to the nozzles. There may be some
evidence of wear patterns indicating that the tip seal travels some distance
(maybe 4-5”) from the point of injection before the oil spreads to the ends of
the seals, but I’m not aware of any direct comparison wear with and without
the air flow. Maybe some of our racing friends can have some input on
this.
Al
Certainly, Al,
nobody seems to know how much good that top lube does, if
any.
Richard
Sohn
N-2071U