Mailing List flyrotary@lancaironline.net Message #27402
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: Re: [FlyRotary] Another Run - with Questions
Date: Thu, 3 Nov 2005 08:31:10 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Joe,
 
Your oil pressure regime appears to be nearly identical to mine so I see no problems there.
You may not get that low a manifold pressure with the rotary I normally see between 12-14"Hg.
EGTs are higher than mine (max 1650-1700F), but mine are installed approx 8" from the port.  Regarding the hot headers at 1600 rpm, you may want to check your ignition timing and make certain you don't have a lot of ignition retarded timing.  See Tracy's instruction manual.  I presume you have set the static timing to his recommended 35Deg BTDC.
 
My headers are make of schedule 40 SS pipe and they are approx 0.10" thick and I have never seen them glow, but assume at higher power settings that they do based on the effect of their radiant heat on some plastic wiring protectors melting.
 
Looks like things are going well for your first runs.
 
Ed A
 
----- Original Message -----
From: Joe Hull
Sent: Thursday, November 03, 2005 1:47 AM
Subject: [FlyRotary] Another Run - with Questions

I ran the engine for an hour straight tonight. It seemed to run well but I do have a couple of questions that maybe this esteemed group can comment on.

 

  1. Engine starts out at about 1300RPM at idle when cold and Oil PSI briefly is 81PSI and then drops to 65 or so after 15-20 seconds. Then as things warm up the RPM’s increase and oil pressure drops.  RPM levels out at about 1550 and oil pressure hovers around 30PSI.  Is 30PSI an OK oil pressure level at that RPM?  I did increase the RPM briefly toward the end of the hour and oil pressure did go up. At 1900-2000 RPM oil pressure was around 50PSI.
  2. At the 1550 RPM the MicroTech says manifold pressure is 9-10Hg (18-20PSI).  Does that sound reasonable?
  3. EGT’s are 2000-2050F.  Seems a tad high to me!!  My EGT probes are located about 2.5” from the rotor housing.  When I shut it down my exhaust manifold/muffler was a very nice glowing red.  It’s made out of Inconel and is .06 thick so it seems to hold up pretty well.  But if it’s like this at 1600RPM what’s it going to be at 5800RPM??

 

Cooling seems to be OK at the moment.  When ever it gets to 212F I’ve got the MicroTech setup to turn on my radiator fan and it immediately heads down and goes to 180F in 1-2 minutes.  Oil temps never got above 150F.  But we are in Washington and the air temp was between 45F and 50F so I’m sure that helped.

 

Thanx (rethinking fuel return and heater hoses)

Joe Hull

Redmond (Seattle), Washington

Cozy MkIV #991 (working on Engine & Electrical & Finishing)

http://www.maddyhome.com/canardpages/pages/JoeHull/index.html

 

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