Brian Martinez
Originally published February 1996
Well folks, in December I left everyone with a brief summation of my flight test experience with my Q-200 experimental. When I first started conceptualizing the engine installation. there was a lot of positive press concerning the Ellison Throttle Body Injector (TBI). The TBI was a very nicely made component, lighter, smaller, simpler, and supposedly more efficient. Little did I know what I would experience in 1995. As I told you before, engine readings for flight with the Ellison TBI installed were as follows:
RPM | MANIFOLD PRESS | IAS (MPH) |
---|---|---|
0 | 27 | ----- |
1000 | 11 | ----- |
1700 | 18 | ----- |
2250 | 25 | 125-130 |
Pnor to liftoff the RPM would roll back from the 2300 static maximum to 2250 and remain there abouts during flight. During the recent holidays I removed the Ellison TBI and replaced it with the standard Marvel Schebler carburetor for a one to one comparison under static conditions. The prop remained the Props Inc. type used previously. The results are as follows:
RPM | MANIFOLD PRESS | IAS (MPH) |
---|---|---|
0 | 27.5 | Static |
1000 | 10 | Static |
1200 | 11.5 | Static |
1300 | 12 | Static |
1400 | 13.8 | Static |
1600 | 17 | Static |
1700 | 18 | Static |
2230 | 27 | Static |
In case you don't do math, I just got 2 inches of mercury back!!!!! During the past year, my aircraft has served as a Ellison TBI test bed. This was not my intention. My Ellison TBI in good condition is currently for sale. For the price of $900.00 OBO I will be happy to provide anyone with the EFS-3 TBI for engines 100-150 HP with an unused factory plenum box (a $300 value). As soon as the Marvel Schebler installation is complete we will see what the new performance looks like in flight. Go ahead Norm, hit me with that cold water again...I love my airplane...I hate my airplane.
(Turns out that wasn't the problem after all. Two years later the actual problem would be determined--see Ellison TBI Unframed!)
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