fiery -> RE: Why (an Enya 11 CX D) Diesel? (7/25/2010 2:26 PM)
Put the little Enya Ultra 11 CXD through it's paces on the test stand today. I acquired the engine pre-loved, but while the previous owner had run it, I had never run it before.
I went to run it last week, but as I was setting up, it's carby fuel inlet nipple fell off as I pulled off the tygon tubing to fuel up. I was less than thrilled. I put it aside and ran another engine.
Later on the workbench at home, the fuel nipple (a press fitting into the carb ?) was cleaned with Baker's fluid and pushed back into place. A nice fillet of solder was laid around it. Much better. Air tight too.
At the field, after sorting a minor fuel tank issue (resulting in me installing a Sullivan "gas" bung into the tank, in place of the rapidly deteriorating standard bung), we were away.
I open the rotor to full throttle. Main needle is opened to 2 1/2 turns, as per the instructions. I adjust the tank height to ensure fuel surface level in the tank was approximately the same as the spraybar in the carb. It would not hold fuel in the line otherwise. Such is life, if the tank is low ... gravity always wins.
After priming and vigourous flipping we had a few pops ... but it would not catch. Feels flooded. Hmmmm. Wind in needle and flick and slowly increase compression (in total about 1/2 a turn) until the wee beast fired and ran out the fuel load in the crankcase. 3 to 4 second run ... good.
Open needle to 1 and 1/2 turns, choke carb with finger for two turns of the prop, and I flick in earnest. I sense it wants to go, so I hit it with the starter, and it catches immediately.
It runs slowly, rich, and undercompressed. Wind in needle to 1 and 1/3 turns open - and increase compression another 1/4 turn - and it sings a lusty song.
This all takes 30 minutes or so. It throttles fine with the carb idle air-bleed screw 1/3 of the way into the air-bleed hole (as I set it up at start - I did not adjust it during running).
As for the rest, the photo's tell the story
Engine: Enya Ultra 11 CXD with R/C carb and stock silencer fiited, no tank pressure.
Fuel: 35% Ether, 2.5% IPN, 20% Castor oil, balance lighting Kerosene (KCB light blue)
Temperature: 16 degrees Centigrade
Elevation: 300 Metres AMSL (approx)
Barometer/ humidity: Not known
Lowest safe idle: 3,200 rpm, but held mid 2000's for some time. At this rpm the carb opening is less than .5 mm. A pin wide crescent.
Max RPM (carb rotor fully open): Steady 10,800; peaking at 11,000
Propeller: Bolly Clubman 8.5 x 6
All in all a fine peformance. I did not attempt to optimise idle setting (air bleed screw).