If I were going to use the metering pump adapter idea, I like Tracy Crooks
ideas to use the older mechanical version with the older front cover.  The
idea of injecting 2 cycle oil via the metering pump is attractive, but I'm
still not sure I want to rely on this setup.  Although very convenient,

if it

were to fail, how would I know until I had an engine failure?

David Doshay wrote:

One friend of mine with a Gen 1 RX7 had the metering pump fail and it ate
his engine. What he noticed from the driver's seat was a period of a few
minutes when power seemed to be dropping off (about 10 miles of city and
freeway driving). After getting off the freeway he noticed a very rough idle,
which he dealt with by keeping a bit of pressure on the throttle. It got him
another 25 miles home in much the same condition, and the next day the
engine would not start. He had it towed to the dealer where the problem was
diagnosed and he bought a rebuilt engine for a replacement.

This event was the time I started considering the rotary for aircraft use. It
seems to me that this is a very graceful way for an engine to die. If while
flying the tip seals fail the power drops to about a third and the engine
keeps running all the way until shutdown, which should be on the ground.

I like graceful failure modes.

But with that said, how often (what percentage of the time) is this the reason
for a rotary to fail? I'm sure it is not amazingly rare, but it also does
not seem
to be so common that it is the way these engines normally die. The system
seems pretty robust. Many of us agree that it is not optimal and we would
rather be burning a different oil, but the pump itself seems OK to me.

David

The big problem is Mazda choose plastic for the oil injection lines. When they
get about ten years old they get brittle and break.

Paul Lamar
 
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