Kelly, et. al.,

I now have over 50 hours of flight on My Mistral engine.  There are problems that I need to fix, but, the early results are good.  Here is a brief summary:

1.  My oil temps are mostly under control.  After many different fixes, including adding air exit area, splitting the incoming air plenum to force more air through the oil cooler, and increasing the size of my oil plumbing, my cruising temps range from 195ºF to 205ºF.  On a hot day, the climb-out temps are still too high and I will be working on that.  Mistral uses the oil injection system, so, I burn about 1 qt. every 5 to 6 hours.  I'm using Idemitsu 20W-50 right now.

2.  Water temps are 183ºF.  I cannot get it to go higher under any circumstances.

3.  At 50% power, my fuel flow is 11 GPH rich and 9GPH lean.  I cannot run much more power than that as the EGTs are too high.  

4.  My EGTs are still too high.  I've been discussing this with the chief engineer at Mistral, and the prognosis is that I have a partially clogged injector.  Since the fuel flows are calculated, they are probably off.  I'm told that  I need a 10 micron filter.  I have a 40 micron now, but I'm told that isn't enough.  

5.  I believe that my air plenum scoop is too big.  I've added a ton of exit area, but I'm still pressurizing my cowl.  Cooling should improve if I cut down the scoop size.  I'll be working on that.  

6.  The airplane is slow.  I'm hoping that I can get better speeds once I cut down on the air plenum scoop.  

7.  I'd also like to get my muffler in the cowl, but with the technology currently available, I don't see how.  Mufflers are just not there.  Mark Steitle is having good results with his DNA, but they have been discontinued. I don't see anything out there that will do the job.  The tangential style mufflers are too power-robbing.  SpinTec mufflers have been recommended in the past, but their shapes are not very aerodynamic.  Anyone that might have a good suggestion, I'm listening.   

Best Regards,

Steve Thomas

_______________________________________________________

On Apr 20, 2011, at 7:23 AM, Kelly Troyer wrote:

Steve,

 

   Other than the muffler how is your ship and its complete "Mistral" firewall forward installation

doing ?..................Are your cooling systems doing the job and is the Mistral "FADEC" single

lever fuel and ignition ECU keeping the EGT under control ?............I am sure the Rotary group

would be interested in hearing some of your numbers such as fuel flow, EGT, oil and coolant

temps, etc................

 

Best Regards,  

 

Kelly Troyer
"DYKE DELTA JD2" (Eventually)

"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold

"TURBONETICS"_TO4E50 Turbo

---

From: Steve Thomas <glasair2@me.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Tue, April 19, 2011 6:24:20 PM
Subject: [FlyRotary] Burns Stainless Muffler Failure

I just did an inspection of my muffler and found that it was basically coming apart inside.  This is a Burns Stainless, 17" 2-Stage muffler after 50 hours of flying behind a 2-rotor engine.  Now, it could be that 50 hours is a reasonable life for something like this, I don't know.  But, it certainly confirms the stories of muffler disintegration.  I've inspected this muffler several times over the last 50 hours, but this is the first time that I've seen damage.  But, when it comes apart, it really comes apart.  It is unfortunate, as the muffler was really effective in reducing the noise and was light-weight.  


Best Regards,

Steve Thomas

_____________________