X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao104.cox.net ([68.230.241.42] verified) by logan.com (CommuniGate Pro SMTP 5.1.11) with ESMTP id 2222775 for flyrotary@lancaironline.net; Tue, 31 Jul 2007 13:49:03 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.42; envelope-from=alventures@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao104.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20070731174824.CJHW23215.fed1rmmtao104.cox.net@fed1rmimpo01.cox.net> for ; Tue, 31 Jul 2007 13:48:24 -0400 Received: from BigAl ([72.192.132.90]) by fed1rmimpo01.cox.net with bizsmtp id WHoQ1X00E1xAn3c0000000; Tue, 31 Jul 2007 13:48:25 -0400 From: "Al Gietzen" To: "Rotary motors in aircraft" Subject: Lessons from yesterday Date: Tue, 31 Jul 2007 10:50:28 -0800 Message-ID: <000001c7d3a3$aa4e80f0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C7D360.9C2D8AE0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C7D360.9C2D8AE0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Ok; vague subject, because this is a collection of stuff, and followup = on an enjoyable flight. =20 As probably everyone else, I am surprised at Buly's decision. As I was flying smoothly along at 195 mph TAS at 5200 rpm; my thought was NO WAY would I give up this rotary in favor of a Lycoming. I'll admit that it = has taken a great deal of tenacity to get to this point; and there is more = to go; but it's a price I'm willing to pay. =20 Gears I just wanted to make it clear that in my post the other day, I was not casting dispersions upon the RD-1B and its planetary gears. I am quite happy with that re-drive and would say its combination of weight, performance and price is the best value out there. And I also was = turned off by Bud's approach of selling imagined emotional issues. If he's = going to sell a re-drive, sell its technical merits. Every choice I made in = the engine installation I made with safety and reliability in mind (and I = have grandkids). His clutch can be a good idea for protecting against = torsional resonance; but what is this about the redrive and prop causing excessive starter loads? =20 Oil cooler =20 I put my two manometer ports at the oil cooler inlet to measure dynamic pressure in front of the center scoop, at the underwing surface, and 1 = 1/8" from the surface (the extremity of the scoop). At the surface (1/4" = tube at the surface) it was +2.75" H2O, and at 1 1/8" it was +8.5". Given the earlier measurement of about +9.0" at 5/8" from the surface; my = conclusion is that there really isn't much in the way of a well defined boundary = layer. Rather there is a thicker layer of turbulent air, probably caused by the gear well/gear doors just forward of the scoop. =20 With the tubes taped along the surface in front of the scoop, climbing = out from a fresh start had the oil temp was up to 230F by the time I leveled = out at 3000' (OAT was 85F). After recording the measurements, I landed with = the intent to relocate the tubes and get more data - but upon reflection, I decided take off the tubes, put the VGs back on and go enjoy some = flying. Starting with a warm engine, and 190F oil temp at the start of the = takeoff roll, I climbed at 1500 fpm to 2500' (TPA) and then about 1000 fpm to = 4500', where the oil temp peaked at about 217F. Obviously have those tubes in, = and in front of the scoop in recent flights had made the problem worse. = Level cruise at 5000 -5200 rpm had the oil temp around 210F - on the high = side, but with the OAT then about 87F, not too bad. Coolant temp was 185F. I think I'll just do some further work on sealing up the air leakage = around the cooler. After all; without cowl flaps or other means of control, if = I made the cooling much better I'll have to be concerned about the oil = getting too cool when the OAT gets to be 40F.=20 =20 Electrical =20 Chris; I'll repeat that word again - Tenacity. I have had continuing = issues with the EM2 and EC2 over the two years or so since I got the engine running. I'd say it is definitely different using them in a composite canard with long wire runs, than in an RV. And there were a couple = issues particular to the 20B version. I've had to conclude that they are not = very noise tolerant. I made a series of wiring routing changes over that = time, and finally added filtering on the circuit board of the EC2. Right now = I'm quite happy with the EC2, and the EM2 just needs a fix to a faulty EGT channel and a change to the FF calibration to adapt to putting the = snubbers in the injector circuits. When they're working right, they are very = nice. =20 =20 Be careful of running the EM2 wiring bundles, and the push-button switch wires, near any other wiring where there likely to be electrical noise; = or near the bundle from the PCM to the EC2 box. =20 Bad news =20 I am going to be grounded for awhile until I can get the FAA = straightened out about my medical certificate. R-r-r-r-r. =20 Al ------=_NextPart_000_0001_01C7D360.9C2D8AE0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Ok; vague subject, because this is a collection of = stuff, and followup on an enjoyable flight.

 

As probably everyone else, I am surprised at = Buly’s decision.  As I was flying smoothly along at 195 mph TAS at 5200 = rpm; my thought was NO WAY would I give up this rotary in favor of a Lycoming. =  I’ll admit that it has taken a great deal of tenacity to get to this point; = and there is more to go; but it’s a price I’m willing to = pay.

 

Gears

I just wanted to make it clear that in my post the = other day, I was not casting dispersions upon the RD-1B and its planetary gears. =  I am quite happy with that re-drive and would say its combination of = weight, performance and price is the best value out there.  And I also was = turned off by Bud’s approach of selling imagined emotional issues.  = If he’s going to sell a re-drive, sell its technical merits. Every choice I made = in the engine installation I made with safety and reliability in mind (and I = have grandkids). His clutch can be a good idea for protecting against = torsional resonance; but what is this about the redrive and prop causing excessive starter loads?

 

Oil cooler

 

I put my two manometer ports at the oil cooler = inlet to measure dynamic pressure in front of the center scoop, at the underwing = surface, and 1 1/8” from the surface (the extremity of the scoop).  At = the surface (1/4” tube at the surface) it was +2.75” H2O, and at 1 = 1/8” it was +8.5”.  Given the earlier measurement of about = +9.0” at 5/8” from the surface; my conclusion is that there really = isn’t much in the way of a well defined boundary layer.  Rather there is = a thicker layer of turbulent air, probably caused by the gear well/gear = doors just forward of the scoop.

 

With the tubes taped along the surface in front of = the scoop, climbing out from a fresh start had the oil temp was up to 230F = by the time I leveled out at 3000’ (OAT was 85F).  After recording = the measurements, I landed with the intent to relocate the tubes and get more data – = but upon reflection, I decided take off the tubes, put the VGs back on and go = enjoy some flying.  Starting with a warm engine, and 190F oil temp at the = start of the takeoff roll, I climbed at 1500 fpm to 2500’ (TPA) and then = about 1000 fpm to 4500’, where the oil temp peaked at about 217F.  = Obviously have those tubes in, and in front of the scoop in recent flights had = made the problem worse.  Level cruise at 5000 -5200 rpm had the oil temp = around 210F – on the high side, but with the OAT then about 87F, not too = bad. Coolant temp was 185F.  I think I’ll just do some further work on = sealing up the air leakage around the cooler.  After all; without cowl flaps = or other means of control, if I made the cooling much better I’ll have to = be concerned about the oil getting too cool when the OAT gets to be 40F. =

 

Electrical

 

Chris; I’ll repeat that word again – = Tenacity.  I have had continuing issues with the EM2 and EC2 over the two years or = so since I got the engine running.  I’d say it is definitely = different using them in a composite canard with long wire runs, than in an RV. And = there were a couple issues particular to the 20B version. I’ve had to = conclude that they are not very noise tolerant.  I made a series of wiring = routing changes over that time, and finally added filtering on the circuit board = of the EC2.  Right now I’m quite happy with the EC2, and the EM2 = just needs a fix to a faulty EGT channel and a change to the FF calibration to = adapt to putting the snubbers in the injector circuits.  When they’re = working right, they are very nice. 

 

Be careful of running the EM2 wiring bundles, and = the push-button switch wires, near any other wiring where there likely to be = electrical noise; or near the bundle from the PCM to the EC2 box.

 

Bad news

 

I am going to be grounded for awhile until I can = get the FAA straightened out about my medical certificate. = R-r-r-r-r.

 

Al

------=_NextPart_000_0001_01C7D360.9C2D8AE0--