flyrotary@lancaironline.net Mailing List Archive

Hi Tim,

No experience with trying to tune a rotary at 6700 + feet density altitude. But, 20.5 " Hg MP seems a bit low at WOT - as I can get 22" while flying at that altitude, but then perhaps not that far off given your operating location.

First, I would double check the cold start wiring - it really sounds like you could have it wire backwards - the reason I say that is that when I accidently turn mine on when the engine is at idle the engine immediately starts to bog and run rough. By fact that when you turn your cold start switch "ON" it runs smooth strong indicates to me that its acting in reverse. So I would check the wiring of the cold start and the injector switches.

Regarding your idle. I could be wrong, but my understanding is indeed MODE 3 adjusts the overall flow to all injectors (may be different on the 3 rotor), a value of 128 is what I use/see on my two rotor. It is the only mode that permits adjusting the primary injector flow. Mode 6 permits adjusting the secondary flow separately.

It could be that you have the overall MODE 3 adjustment a bit too rich at 168. The fact that you have to lean it considerably also indicates that. The fact that the engine gets rough if you try to add more fuel could also indicate too much fuel - excessive fuel getting into you muffler/exhaust could lead to back firing.

On the other hand your O2 sensor at one bar (presumably from the lean end) would seem to indicate too lean. Is if possible that your O2 sensor is just in one of the headers for one of the rotors and while that rotor might be lean - the other rotors could be running rich? Or do you have it located where more than one rotor's exhaust hits it? Does the O2 sensor indicator ever show more than one bar????

I would suggest adjusting the MODE 3 at idle until you get a nice solid idle (try 128 or just keep decreasing until the idle smooths out). Then I would go to Mode 6 (on the two rotor, I assume it’s the same on the 3 rotor) which is the secondary injector differential adjustment. Then I would increase that value until you get the high end response you are looking for. I think you may have it a bit too rich to get a good idle. This based on 2 rotor viewpoint.

Good luck

Edward L. Anderson
Anderson Electronic Enterprises LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com

From: coastiefamily4

Sent: Saturday, September 03, 2011 1:05 PM

To: Rotary motors in aircraft

Subject: [FlyRotary] Tuning 20B

I have just finished setting MODE 3. I am tuning it at 6700ft here in Colorado Springs and I could only get 20.5 MP running at 6000 RPMs. It is running smooth, but I think it could be smoother. I will finish it with MODE 1. I had to set the Injector flow rate at 163.

Just finished trying to adjusted the idle setting in MODE 2 and I am still having a difficult time getting the engine to smooth out at idle. While at 1800 rpms with cold start off, fuel pressure at 38psi I have to really lean it out to get it to run smoothly, it is at a setting that is too lean and the engine tries to quit. The O2 reading in just one bar on the scale. Then when I try to increase the mixture she get really really rough and occasionally will backfire.

Then when I switch back to MODE 0 and place the cold start switch on she begins to purr nicely and she is very smoothly.

I am a little stumped, I know when the cold start is turned on it doubles the fuel, but at idle with only the primaries firing if the cold start is turned on will it fire both the primary and secondaries or double the flow on just the primaries and not fire the secondaries? If I new the answer to this it would help diagnose the issue.

I am also battling oil leaks. I have a few of the oil pan bolts leaking, I am going to have to pull then out and fill clean the oil out and then place them back in with pro seal. I tried with grey gasket maker, with no joy. I think i might have also have a leak coming from one of the bolts on the mounting plate of the RD1C. I am going to have to look into this leak a little farther. Never ending oil leaks.

I can handle to leaks, at least I know where they are.

Any suggestions with the idle tuning.

I think I might have to purchase the Data Logger from Tracy in order to see all the values. Luckily, I already wire for it, I just have to hook it up.

Tim