Subject: Airflow Performance FI Pump Drive
From: Rotary Engine
Date: 3/12/2008, 7:27 AM
To: AAA Put this in the To box


 >>> > How was the Airflow Performance FI fuel pump driven when installed on
 >>> > the rotary?  I think it's gear driven on a LyCont..
 >>> >
 >>> > Side question: Did the the FI use one orifice (injector) per rotor
 >>> or two?
 >>> >
 >>> > Another side question:  Where did the FI measure the equivalent of
 >>> deck
 >>> > pressure (manifold pressure) when mounted on the rotary?  I was
 >>> thinking
 >>> > the engine it was installed on was P-Port with a slide throttle.  Were
 >>> > there any particularly difficult challenges with metering accuracy
 >>> when
 >>> > at high power settings?
 >>> >
 >>> >
 >>> > Regards,
 >>> >
 >>> > Matt-
 >
 >>> I think Steve BeckHam can answer those questions as the early Power
 >>> Sport engines
 >>> use Airflow Performance fuel injectors.
 >>> --
 >>> Paul Lamar ...No rotor no motor.
 >>
 >> Thanks Paul..  I couldn't remember who said they had been using the
 >> Airflow Performance..  Yes, Steve Beckham.
 >>
 >>
 >> Matt-
 >>
 >> Also many racing engines used mechanical fuel injection.
 >> Here is a picture. Also a rather grainy picture of the PS engine.
 >>
 >> BTW guys please look at all the Youtube videos and click on the fifth
 >> star over where it says ratings. A good search phrase is RX7 Airplane.
 >> That gets you to the right place. Than click on More From: UTUBPLEASE
 >> That will show you all 18 rotaryeng.net videos.
 >>
 >> We need to promote RX8 sales as Mazda needs to keep making rotary engines
 >> until some other major manufacturer wises up and starts making turbo
 >> compound rotaries for street cars. I suspect Mazda management lacks
 >> a bit of vision on this subject or they would have done it years ago.
 >>
 >> The piston engine guys are going to have a heck of a time with
 >> turbo compound as half the heat and kinetic energy goes towards
 >> destroying the exhaust valve. The exhaust valve was the  Achilles heel
 >> of the CW R3350TC. CW spent most of the development money dealing with
 >> that problem.
 >>
 >> Also keep an eye on Popular Science or Pop Mechanics.
 >> Reputedly there will be an article by Don Sherman on the
 >> turbo compound truck engines shortly. Send email to the mag
 >> and tell them how much you enjoyed the turbo compound article
 >> whether he does a good job or not :)
 >>
 > > Paul Lamar
 >
 > paul,
 > my experience, and referral to Don Rivera's manual, indicate Airflow
 > Perf generally uses electric FI pumps on LyCont.  I have both a cam
 > driven mech pump and an electric Boost Pump on my Lyc 0-360 w/ FM200.
 > Ck his website
 >
 > steve wolpin
 >
 >
 > Thanks Steve.
 >
 > Paul

 Matt:  Paul was correct.
 On all the Powersport prototype rotary engines from 1990-1998, we used Don
 Rivera's fuel controller/servo on all the later  Superlight prototype
 engines and the last version which was the Mazda conversion engine.  You
 asked about fuel pumps and other.

 Hope the following notes help.  Don's
 AirFlow Performance unit is a refinement of the Bendix constant flow,
 mechanical fuel injection system used on certified engines.  Don worked for
 Bendix and all those experiences served him well.  Don's units work with
 either engine driven pumps (ie. standard Lycoming practice) or dual electric
 pumps, which is what we used on the rotary engines.  The signal for Don's
 Airflow Performance units use a highly effective venturi.  This venturi
 creates the signal for the fuel controller/servo....the more airflow, the
 more pressure differential and that alters the mixture accordingly.

 His
 unit also provides  manual mixture control to refine the mixture based on
 altitude,EGTs, etc.    On Don's standard Lycoming units, his castings
 include everything in one nice casting. For our rotary engines, we sought to
 package the system as tightly and simply as possible so Don provided us a
 "detached" controller/servo and we made our own venturi.  This allowed us to
 mount the servo right next to the housings and in line with the throttle
 arms coming out of the rotor housings.


 Our engines had the throttle plates
 located in the rotor housing peripheral ports.  So we used an interconnect
 between the two throttle plates and another heim jointed arm connected
 directly to the servo controller.  Detaching the fuel controller/servo
 allowed us to put the venturi in the inlet of the plenum chamber.  We also
 use AirFlow Performance  dual electric pump package and all other necessary
 goodies such as relief valves, etc.  It is all good stuff.

 We had used many of Don's Airflow Performance units on Lycoming engines we
 built for customers during those years and Don's equipment performed
 flawlessly.  And they worked without a hitch on all our rotaries as well.
 When we were using direct injection with injectors screwed directly in the
 trochoids, we used vented nozzles.

 When injectors were used in the ram
 tubes we used unvented nozzles.  I have detailed photographs of these
 installations in the RV-3 and RV-4 if it would be helpful  for you to better
 understand how this all went together. When it comes to mechanical fuel
 injection systems, Don and his people are great resources and a delight to
 work with.

 Steve Beckham


Thanks Steve..

I think your implementation is the way to go.  I might be tempted to
try a mechanical pump, but I can see going either way on that one.  If
people went down this path they would spend a bit more money up front,
but I think the end result would be more successful rotary engine
installations and maybe less money spent in the end.


Regards,

Matt-



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