Return-Path: Received: from [216.52.245.18] (HELO ispwestemail1.aceweb.net) by logan.com (CommuniGate Pro SMTP 4.1.3) with ESMTP id 2578575 for flyrotary@lancaironline.net; Sat, 13 Sep 2003 22:32:04 -0400 Received: from 7n7z201 (unverified [208.187.45.41]) by ispwestemail1.aceweb.net (Vircom SMTPRS 2.1.258) with SMTP id for ; Sat, 13 Sep 2003 19:34:35 -0700 Message-ID: <014f01c37a68$e51ee320$272dbbd0@7n7z201> From: "William" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Good news, Bad news Date: Sat, 13 Sep 2003 21:35:41 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_014C_01C37A3E.FAF18880" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 This is a multi-part message in MIME format. ------=_NextPart_000_014C_01C37A3E.FAF18880 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageGood to hear that your cooling worked so well. I would have = guessed that the oil cooler getting the air first would work better, but = you must have LOTS of extra cooling capacity for it to work so well with = the air being heated by the radiator first. =20 Have you tested climb rate at lower speeds, where drag is less = important? Also, you could try reducing the size of the inlet to the = Radiator scoop to see if that reduces cooling drag, since you have = excess cooling available. Please keep the data coming, we are all learning. Bill Schertz ----- Original Message -----=20 From: Russell Duffy=20 To: Rotary motors in aircraft=20 Sent: Saturday, September 13, 2003 9:01 PM Subject: [FlyRotary] Good news, Bad news Greetings, Well, the log below pretty much says it all. =20 Decisions, decisions... Rusty 9-13-03 1 hour / 2.0 hours total =20 Made 2 flights today. On the first, I noticed that it take some work = to get the oil temp up to 130 before takeoff. I guess this was my first = sign that the new cooler was working. The second sign was during climb. = The oil and water both stayed right at 180 degrees during climb and = cruise. During descent and landing, I noticed that the oil drops pretty = quickly to 130, which I can live with. The RPM at 30 inches MAP, and = 100 mph in climb was 5400. This is really pretty much perfect, and I = know that it will go to 6300 with 36 inches of MAP. Sadly, the climb = performance just isn't there. I tried everything from 90 to 110 in = climb. If I try to get to 120, I'm basically flying level and not = climbing at all. Best climb was probably around 95 mph, which is just = way lower than it should be, and the rate was only about 1000 fpm at = best. Once I leveled out, I ran at 30 inches of pressure, and 6000 rpm, = with only a 130 mph speed to show for it. This is horrible! Finished = the flight with a bouncy attempt at a wheel landing. At least they were = gentle bounces, so it's an improvement. =20 =20 Out of desperation, I set the prop back to 14 degrees (it was on 12). = I couldn't rationalize how this would help, but it was worth a try. I = also disabled the relief valve, to see how much boost I could get at = altitude. Well, this climb was even more dismal than before, with an = rpm of 4900 at 100 mph. Best climb rate was still in the 95 mph range. = I only managed to get up to 4000 ft, because it was just taking too = long, and there were some clouds around to complicate things. At 4000 = ft, I advanced the throttle to see how much boost I would get. Knowing = that I have run 3 psi on the ground, I should be able to run 5 psi at = 4000 feet, and have the same MAP. The boost is very smoothly = controllable with throttle, which is the good news, but I got to 5 psi = quite a bit before I got to full throttle. I stopped there, so as not = to tread new engine territory in flight, but I'd estimate that I would = have gotten another couple psi out of it, for a total of 7. This is = with the wastegate fully open. I need a bigger wastegate, or some = exhaust restriction. During descent from 4000 ft, I noticed that the = plane just doesn't want to go over 130 mph, even downhill. I was = descending at 2000 fpm, with 20 inches MAP, and still only 130 mph. = This sure ain't how the RV-8 worked. The one really good thing was that = my landing was beautiful? A real squeaker!!! =20 =20 Unfortunately, I've come to the conclusion that the current big ugly = cowl is a much bigger problem than I figured. I've got a lot of = decisions to make. Do I keep the turbo- I like it, and it works, so I'd = like to. Do I try to work on it at the hanger, or do I just pull the = wings off, and take it back home. This makes more sense, and wouldn't = be that hard to do. It's just painful to think about. ------=_NextPart_000_014C_01C37A3E.FAF18880 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Good to hear that your cooling worked = so well. I=20 would have guessed that the oil cooler getting the air first would work = better,=20 but you must have LOTS of extra cooling capacity for it to work so well = with the=20 air being heated by the radiator first. 
 
Have you tested climb rate at lower = speeds, where=20 drag is less important? Also, you could try reducing the size of the = inlet to=20 the Radiator scoop to see if that reduces cooling drag, since you have = excess=20 cooling available.
 
Please keep the data coming, we are all = learning.
 
Bill Schertz
----- Original Message -----
From:=20 Russell=20 Duffy
Sent: Saturday, September 13, = 2003 9:01=20 PM
Subject: [FlyRotary] Good news, = Bad=20 news

Greetings,

Well, the log=20 below pretty much says it all. 

Decisions,=20 decisions...

Rusty

9-13-03  = 1=20 hour  / 2.0 hours=20 total

 

Made 2 flights today.  On the first, I noticed that = it take=20 some work to get the oil temp up to 130 before takeoff.  I guess this was my first = sign that=20 the new cooler was working.  = The=20 second sign was during climb.  = The=20 oil and water both stayed right at 180 degrees during climb and = cruise.  During descent and landing, = I noticed=20 that the oil drops pretty quickly to 130, which I can live with.  The RPM at 30 inches MAP, = and 100 mph=20 in climb was 5400.  This = is really=20 pretty much perfect, and I know that it will go to 6300 with 36 inches = of=20 MAP.  Sadly, the climb = performance=20 just isn’t there.  = I tried=20 everything from 90 to 110 in climb. =20 If I try to get to 120, I’m basically flying level and = not climbing at=20 all.  Best climb was = probably=20 around 95 mph, which is just way lower than it should be, and the rate = was=20 only about 1000 fpm at best.  = Once=20 I leveled out, I ran at 30 inches of pressure, and 6000 rpm, with only = a 130=20 mph speed to show for it.  = This is=20 horrible!  Finished the = flight=20 with a bouncy attempt at a wheel landing.  At least they were gentle = bounces, so=20 it’s an improvement. =20

 

Out of desperation, I set the = prop back to=20 14 degrees (it was on 12).  = I=20 couldn’t rationalize how this would help, but it was worth a = try.  I also disabled the relief = valve, to=20 see how much boost I could get at altitude.  Well, this climb was even = more dismal=20 than before, with an rpm of 4900 at 100 mph.  Best climb rate was still in = the 95=20 mph range.  I only = managed to get=20 up to 4000 ft, because it was just taking too long, and there were = some clouds=20 around to complicate things.  = At=20 4000 ft, I advanced the throttle to see how much boost I would = get.  Knowing that I have run 3 = psi on the=20 ground, I should be able to run 5 psi at 4000 feet, and have the same=20 MAP.  The boost is very = smoothly=20 controllable with throttle, which is the good news, but I got to 5 psi = quite a=20 bit before I got to full throttle. =20 I stopped there, so as not to tread new engine territory in = flight, but=20 I’d estimate that I would have gotten another couple psi out of = it, for a=20 total of 7.  This is = with the=20 wastegate fully open.  I = need a=20 bigger wastegate, or some exhaust restriction.  During descent from 4000 ft, = I noticed=20 that the plane just doesn’t want to go over 130 mph, even = downhill.  I was descending at 2000 = fpm, with 20=20 inches MAP, and still only 130 mph. =20 This sure ain’t how the RV-8 worked. The=20 one really good thing was that my landing was beautiful?  A real=20 squeaker!!!   =20

 

Unfortunately,=20 I’ve come to the conclusion that the current big ugly cowl is a = much bigger=20 problem than I figured.  = I’ve got=20 a lot of decisions to make.  = Do I=20 keep the turbo- I like it, and it works, so I’d like to.  Do I try to work on it at = the hanger,=20 or do I just pull the wings off, and take it back home.  This makes more sense, and = wouldn’t be=20 that hard to do.  = It’s just=20 painful to think about.
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