Mailing List flyrotary@lancaironline.net Message #27414
From: Joe Hull <joeh@PilgrimTech.com>
Subject: RE: [FlyRotary] Re: Another Run - with Questions
Date: Thu, 3 Nov 2005 07:42:52 -0800
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

>> presume you have set the static timing to his recommended 35Deg BTDC.

I’m pretty sure mine is at 5-10Deg BTDC. When I checked using Lynn’s patented tooth counting process I found the Crank Angle pickups to be perfectly aligned and the yellow dot was about .5” ahead of the pointer. 

Here’s what I’m guessing I need to do:

  1. Set engine at TDC (I did mark the TDC tooth on the flywheel so that should be easy).
  2. Mark the main pulley wheel for TDC
  3. Measure the circumference of the main pulley – divide by 72 to get 5Deg increments (e.g. 6.5” = .090”) and/or measure the flywheel (bigger circumference and therefore better resolution)
  4. Make a mark at the 35Deg position (or .135 of the circumference from TDC)
  5. Adjust the Crank Angle Sensor accordingly.

 

Does this sound right?

 

>>What does your fuel mixture meter show? I guess you could be running so rich that you have a nice fire going in the headers...

The MicroTech says the A/F is between 13-14. Starts out closer to 13 and works its way up to closer to 14 as it warms.

I’m going to check the timing again and retard it some more.

 

Thanx,

Joe Hull

Redmond (Seattle), Washington

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

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

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Finn Lassen
Sent: Thursday, November 03, 2005 5:47 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Another Run - with Questions

 

Joe Hull wrote:

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.

I think the factory manual says at least 1 PSI per 100 RPM so it looks like you're fine.

  1.  
  2.  
  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??

What does your fuel mixture meter show? I guess you could be running so rich that you have a nice fire going in the headers...


Finn

 

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