Somebody mentioned they thought the oil injection pump was not a pump at all
but just a metering device that relied on engine oil pressure.

Not the case. The oil injection pump is indeed a pump and is gravity fed with oil at
atmospheric pressure. The pumping action comes from the fact that the plunger
moves up and down in its bore as shown in this drawing from the Mazda book 
called "Rotary Engine". The stroke of this up and down motion hence the amount of
oil injected is controlled by the throttle opening linkage.

The mechanical  pump is an off the shelf motor cycle part bought out by Mazda.
As I recall it is made by Mikuni.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.

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