|
Test Pilot Tom Porta made his third flight today. He is a high time RV driver. I'm low time and don't want to be a dummy. Oat 40. max altitude 8500, field elev 5000 no wind day.
rpm oil temp water temp
Take off. 6000 rpm, , 190-205 182-190
cruise 6000 200 177
max throttle 6800 205 183
MPH at cruise is 163 via GPS. Dynon reading about 12 mph slower.
Sorry, no Egts or rate of climb. I am finding that the Egts are in line with the 13b and going as high as 1730 during ground testing and not what was suggested as maxing out at 1550. Glad I Jet Coated with the 2000 degree stuff. We did get 1675 at 6500 rpm on the 2nd flight. Egt probes in the exhaust tube, 3 inches from the engine. Tom says it flys like an RV and is smooth and quiet. When he made a pass, I could only hear the prop until he passed and then the engine could be heard, but the prop was still most of it. Hushpower 2. He didn't play with the mixture much. Next time he or I will add fuel to the mixture to see if the power comes on.
Notes: When switching fuel pumps, #1 switches fine, #2 takes a few seconds to come on, and drops in pressure, so the engine almost drops out and then comes back up. And thats with both on for a few seconds. The pumps sound different too. I put diode on the pumps, but that is not it. I'll be getting the new ones from Tracy and changing over. And saving 2 pounds! Pumps on the fire wall, low on the left, shielded, with a blast tube.
The RPM display is dropping out (going to 0) above 6000RPM and coming back on and off. I used Tracy's fix of a .01uf cap from +12 to ground on the EM-2 and it's better, but need more. When warm and throttling back, the engine runs rough and pops a little. More tuning needed, probably mode 2. As usual, cooling is the main problem. It's OK now, but when things warm it will be too hot. My configuration is similar to Tracy's RV8 with the 3 rotor. I have had a slight improvement with the water by narrowing down the duct at the far end (to force more air through the front) (no manometer measurements have been taken) and adding smoothing panels where the air discharges from the radiator. I tried turning it into a James cowl with outlets on the outside of the cowl, but that made it worse. A lot of time and trouble. I blocked off the sides of the flywheel so no air would blow out on the rad or oil cooler, but no difference. My next plan is to open the bottom of the cowl when the air discharges a little to see if there is a difference. I notice that what is working for others is cowl flaps, But there are no pictures. Pictures anyone??!!b I'll also be switching to Maxdatrixes version of water wetter this week. There are a few other ideas too, but that will wait until new pumps and this is tried. If the oil doesn't cool down, I"ll add an additional cooler under the redrive (the lines run through there now) and build a chin opening near to the prop to feed it. My existing cooler is a racing one, slightly bigger than the mazda and rated for 350 psi.
Don Walker
RV-8 Renesis, EM-2, EC-2, Catto 76/88 1131 LBS CG center of envelope
Intake tuned to 17.5 in but not as smooth as I would like
exhaust at 24 inches all three tubes.
|
|