Hi Paul-

    Apparently a rotary in full song is not very subtle.  We were running
    today to continue the tuning exercise & attracted visitors from all over
    the airport.   A friend of ours heard the engine from inside his hangar
    1/2 a mile away and knew we must be up and running again.  We dropped
    the fuel pressure to 38psi, and reduced the injected amount of fuel by
    some amount (Tracy neglected to count the number of steps).  We had the
    engine running beautifully smoothly at ~4000rpm for 5 - 10 minutes or
    so.  We had to knock it off when oil temp went over 205F.  Happily water
    temp came up to around 190F and stayed there.  Mixture map is all over
    the place, so any other rpm required leaning or enriching to run
    smoothly.  I'm still not happy with the throttle behavior - it remains
    much touchier than I like, but we'll see how it does once we start
    getting the map values more consistent.  I'd like to talk directly to
    Mike Wills -- tuning is clearly going to take a while & any tips he
    might have would be welcome.  We would have tried running the
    auto-mapping function, but the oil hadn't cooled enough from the earlier
    run & was back up at 205 after a few minutes at 4500.

    One strange behavior -- when we shut down, we seem to always have a
    single 'backfire' around 1 second after everything stops moving.  I'm
    guessing we're super rich at the bottom end or something.

    Mark (Rocky Mtn High)

    You can quiet it a bit with something like this. If it melts
    it is not likely to plug up the exhaust and cause a loss of power.
    Use about .090 or .125 thick 321 SS. 5 minutes at 4000 RPM oil
    temp 205 is not that bad. What kind of manifold pressure are you
    seeing at 4000 RPM?

    Paul Lamar


See photo attached taken after we finished the first tuning run.   MP of
23.2 seems about right for that rpm.

Note that my partner's name is Terry -- not Tracy as you corrected above.

Any thoughts on the backfires?

Mark (Rocky Mtn High)

Sorry.
Sounds rich :)

Paul Lamar