Greetings,

The following is some of my log entry for today.  Looks like the first rev-2 flight will happen next weekend (hopefully).

Rusty

I tried tuning the engine again.   The O2 reading is still out to lunch, but I got it running fairly well, except for a couple issues.   From idle, to full throttle, there is a hesitation.  This can be corrected by turning the mixture a bit richer, but that screws up the idle.  Attempts to work out this mixture imbalance failed, partly due to the fact that I can’t read the O2.

The other issue is when you chop the throttle from a high setting, to idle.  This is very strange.  Say the idle is set at 1900 rpm, and I’m running at high throttle.  When I chop the throttle, the rpm goes low, to around 1600 and stays there.  During this time, the MP is 16.0, and the engine is very rough.  It will stay here forever, but if you turn the mixture knob about 90 degrees CCW to lean it out, it smoothes out, the rpm increases to 1900, and the MP drops to 13.0.  If you are at a higher throttle setting, and decrease throttle more slowly, it will come down to 1900 rpm, 13 MP, and smooth.  It also seems like the engine is jumping back and forth between the dual map ranges, and I believe this false 16" MP reading at the rough, low idle is from the dual map.  I think I even proved that to myself by watching the EM-2 screen that shows EC-2 readings.   I’ve got some work to do on this one, but it's just a tuning issue. 

Another note for Tracy- turning off the primary injectors makes the EM-2 rpm double.  It makes for an impressive HP figure though :-)  Speaking of HP, mine reads 225 HP at 4900 rpm.   Yeah, I wish :-)  The down side to having an engine monitor with so many functions, is that it will take some serious time to get the thing dialed in.   

Good news, my old problem of mismatched injectors (primary vs secondary) is gone.  I can now switch off the primaries, and not even be able to tell that it switched to the secondaries.  Gotta love that. 

After more than an hour of torturing the Lycoming guys, I decided to try hooking up my old air fuel gauge to see if it would read better than the EM-2.  I added wires to it, hooked up the power, extended a wire to reach the O2 sender, and promptly found that the O2 sender was falling apart.  It was screwed into the pipe just fine, but the outer part, the inner cover, and the element itself were all flopping around independently of each other, and the main housing.  Just a wild guess, but I’m thinking this is bad :-)   I stopped by the auto parts place on the way home, where a busy, and grumpy (because I couldn’t give him a year, make, and model vehicle) guy produced a single wire Bosch sensor.  The one I got was #11051, and seems to be the heavier duty import sensor.  The price was $30.  There is also a $20 sensor #12013 that is just like the one that fell apart.  I splurged, and paid the extra $10.  I was all ready to order a new FJO wideband unit, and I still might. 

Some numbers from the run (cowl off, but rad inlet ducts in place):

Oil temp- 165 (max was 185 at full throttle for about 2 minutes)

Water temp- 175 (distilled water only so far, max was 190 at full throttle for about 2 minutes)

Water pressure- 25 psi (29 psi cap)

Oil pressure- 74 psi at 2000 rpm  (seems high, need to check cal)

Voltage with alt on- 14.2 V  (alt off was 12.3)

Max static rpm is 4900 when mixture is at best power.  EGT’s were in the 1600 range. 

I also found that my “scat” tubes for the tb inlet were trying to suck themselves shut on the bends.  I ordered some “sceet” tubing to correct this.  Eventually, I’ll make some hard pipes for the bends, if I don’t change the arrangement. 

Finally, I’ll try to spend some time this week verifying calibrations on the EM-2.  I have spare senders for most of the functions, and will have to find a way to simulate pressures.  The fuel gauges are in desperate need of cal.   About one more round of tuning, with a functioning O2 meter, and it should be ready to fly.