X-Mozilla-Keys:                                                                                 
Chris Gentry wrote:

Hi Paul
Thought this might be interesting to the group.
I wonder how well a 20B Turbo would go in my Grumman Cheetah?
Best Regards,  Chris Gentry

Grumman Cheetah, Glasair(Rotary) & Dragonfly

  A curious listing in Second November 1999 Trade-a-Plane led
  me to divert recently on my way back to NC from Florida:

 ==============================================================

    1974 Grumman AA-1B Experimental, modified with a
    Mazda RX-7 180 hp, IVO electrical prop, 75 hrs TTSN,
    MX-70 NavCom w/GS, Full IFR panel, transponder w/encoder,
    Foster LORAN, new glass, leather seats, yellow & blue
    military paint, strobes, licensed amateur homebuilt,
    A&P built over 13 year period.  $22,500.
    770-252-3123 work, 770-964-8630 home.

 ==============================================================

  The builder is Bill Fisher, an A&P/IA, and the airplane is at
  his paint shop at the Newnan, GA airport just SW of Atlanta.

  The "Experimental" Airworthiness Certificate was based on
  his assembling the airplane from various spare parts, plus
  the un-certified auto engine installation.  More than four
  deceased AA-1()'s contributed components to the re-birth.
  The wings are from an AA-1C Lynx, the fuselage an AA-1B.

  Registered: N9990L, AA-1B Grumman/Fisher
  Empty weight: 1220 pounds.
  Performance: 1500 fpm climb to a 155 mph max. cruise.

  The RX-7 engine came stock with dual ignition, and his
  aircraft installation uses two small radiators, two oil
  coolers, two electric fuel pumps, two ignition systems,
  two batteries, one 65-amp Bosch alternator, a Ross engine
  mount, and a Ross propeller speed reduction unit.

  A standard aircraft updraft carburetor is mounted, and
  both cabin and carb heat are supplied by an airplane style
  exhaust-muff.  The cowling and nosebowl are stock AA1 with
  major modifications ( holes and vents ).  The electric tach
  is driven by only one of the ignition systems.  The cars'
  smog pump is employed as a vacuum source for the gyros.

Are you near the airplane Chris? What year RX7 engine?
Distributor or crank angle sensor? Upright or layed
over engine?

I think the 20B would be too heavy for a Cheetah. 

BTW One needs to modify a lot more in the airplane than
just the engine, like this man did, to get the FAA to 
give one an unrestricted experimental license. The FAA does
not want people putting their certified airplanes in the
experimental catagory merely to by pass the rules so
they draw a line somewhere. Where that line is nobody 
really seems to know. I would check with the local FSDO
and get them to write to you informing you just what
and what you can and cannot do with if you change the 
engine to a non-certified type.

 

Paul Lamar
 
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