Return-Path: Received: from mail.theofficenet.com ([65.166.240.5] verified) by logan.com (CommuniGate Pro SMTP 4.2b8) with SMTP id 324517 for flyrotary@lancaironline.net; Sat, 17 Jul 2004 09:28:04 -0400 Received-SPF: error receiver=logan.com; client-ip=65.166.240.5; envelope-from=jackoford@theofficenet.com Received: (qmail 1814 invoked from network); 17 Jul 2004 13:14:05 -0000 Received: from ip-66-45-202-202.nw-tel.com (HELO jack) (66.45.202.202) by mail.theofficenet.com with SMTP; 17 Jul 2004 13:14:05 -0000 Message-ID: <000f01c46c01$c9780670$caca2d42@jack> From: "Jack Ford" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: 11th test flight Date: Sat, 17 Jul 2004 06:27:18 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000C_01C46BC7.1C188750" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_000C_01C46BC7.1C188750 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks, Steve, Ed Anderson also put me in my place with an earlier post. So where de we get higher temperature seals? Jack Ford ----- Original Message -----=20 From: Steve Brooks=20 To: Rotary motors in aircraft=20 Sent: Friday, July 16, 2004 7:00 PM Subject: [FlyRotary] Re: 11th test flight Jack, I think that the redline on the rotary for oil temperature of 240F is = more a factor for the rubber seals rather than for the oil. I am = running synthetic oil, which doesn't breakdown until quite a high = temperature, but according to what I've been told, and read, the seals = can be damaged way before you have oil breakdown issues. =20 I did take the thermostat out, but the stock thermostat that was in my = engine was 195 degrees, so 200 certainly seems to be a reasonable = temperature.=20 =20 Steve Brooks=20 =20 -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On = Behalf Of Jack Ford Sent: Friday, July 16, 2004 9:50 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: 11th test flight =20 You dasn't ever want to run straight H2O in your cooling system. I just went out to the shop and checked a container label for engine = coolant (Wal-Mart variety). Sez boiling point for 50/50 mixture with H2O = is 265 deg.F. Put a 16 psi cap on that and it goes up some more. If coolant and lubricant failure are the criteria for establishing = redline temps, my post of the other day is valid. I think 210-220 degree temps should be good running temps, not = redlines. Modern (Post model A) engines run more efficiently at those = temperatures. But I'd still like to hear an opinion from a 13b authority or two if = there are other criteria for coolant and oil temperature limits. FWIW, again, Jack Ford ----- Original Message -----=20 From: Dale Smith=20 To: Rotary motors in aircraft=20 Sent: Friday, July 16, 2004 4:18 PM Subject: [FlyRotary] Re: 11th test flight =20 Steve Brooks wrote: I made a test flight today with the new scoop, but also wit cooler OAT = (70F)than I've seen in the last couple weeks. I flew for 6 tenths of an = hourwith temperatures for the oil at 207 and coolant 200 stabilized at = 4700RPMs. I increased the throttle to 5300 RPMs and the coolant stayed = put, andthe oil increased by only 3 degrees. I was about 1500 AGL for = the entireflight. I did descend a few hundred feet and climb a few = hundred feet towatch the temperatures, but usually was flying a level = circle around theairport. I reduced the throttle to 4300, and = maintained level flight atabout 105 kts. Oil dropped to 195 and coolant = to 190. I guess that the good news is the I could fly all day at those = temperatures,and I never saw any temperatures higher than 210, though I = really didn't doan extended climb. I really didn't push level cruise = higher than 5300 (135kts), but the temperatures seemed to be holding, = and actually the oildropped a degree after letting it stabilize a couple = of minutes. The bad news is that the scoop appears to be costing me = about 10 kts, whichI was expecting. I also don't have any wheel pants = yet on the main gear, soit's not like I'm out to win any speed test at = this point anyways. My oilcontinues to run higher than the coolant = which indicates to me that I needto do some more baffling to divert more = air to the oil cooler. I also have not done any filling or finishing to = the scoop, so it's surfaceis more like sandpaper right now. Finishing = it will probably improve airflow some more, and also reduce some of the = drag. I left the scoop on theplane for now, so that I can hopefully = get another flight in tomorrowmorning. My plan tomorrow is to climb up = to 5000' and see what I get there.Then I'll remove the scoop, which = takes about 5 minutes, and bring it homefor some filling and sanding. = And after a few more flights, and morefilling and sanding, some primer = and paint. I am still looking at this as a "hot weather scoop". My plan = is to removeit during cool weather, and re-install it for June-August. = I mount thescoop using 6 10-32 SS screws into nutplates embedded in the = landing gearcover, plus 2 of the screws that mount the landing gear = cover to thefuselage. It's not likely to come off on its own. Steve = BrooksCozy MKIVTurbo Rotary - 6.3 hours and counting Steve ... re: the = above underlined. I would say that what you have is just fine regarding your oil temp. = Remember that the "delta T" between where you are running and the = temperature at where it quits working is quite high. Especially if you = are using synthetic oil. Molbil I keeps lubricating quite well up past = 400 degrees and beyond. Thus, if you are running temps near 200 = degrees you have near a 200 degree temp spread (delta T) between what = the oil can take away and what it IS taking away in BTU's of heat = dissipation in a stable system. That is a pretty fat safety margin, = when you figure you can run 100 degrees hotter than what you are now and = still have 100 degrees left before lubrication failure is imminent. = Obviously, lower is better. Water cooling now is a different story. operating coolant at temps = near 200 while water boils at 212 ... gives you a delta T of just 12 = degrees to play with. I know you can kick it up by anti-freeze, = pressure on the system, etc. etc. but the bottom line is that you have = a lot narrower delta T range to deal with, and you are always working = the system a lot closer to near it's maximum potential for heat = dissipation. Just a thought, Dale Smith ------=_NextPart_000_000C_01C46BC7.1C188750 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks, Steve,
Ed Anderson also put me in my place = with an earlier=20 post.
So where de we get higher temperature=20 seals?
Jack Ford
----- Original Message -----
From:=20 Steve = Brooks
Sent: Friday, July 16, 2004 = 7:00 PM
Subject: [FlyRotary] Re: 11th = test=20 flight

Jack,

I=20 think that the redline on the rotary for oil temperature of 240F is = more a=20 factor for the rubber seals rather than for the oil.  I am running synthetic oil, = which=20 doesn=92t breakdown until quite a high temperature, but according to = what I=92ve=20 been told, and read, the seals can be damaged way before you have oil=20 breakdown issues.

 

I did=20 take the thermostat out, but the stock thermostat that was in my = engine was=20 195 degrees, so 200 certainly seems to be a reasonable temperature.=20

 

Steve=20 Brooks

 

-----Original=20 Message-----
From: = Rotary=20 motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of Jack = Ford
Sent: Friday, July 16, 2004 = 9:50=20 PM
To: Rotary = motors in=20 aircraft
Subject: = [FlyRotary]=20 Re: 11th test flight

 

You = dasn't=20 ever want to run straight H2O in your cooling=20 system.

I just = went out to=20 the shop and checked a container label for engine coolant (Wal-Mart = variety).=20 Sez boiling point for 50/50 mixture with H2O is 265=20 deg.F.

Put a 16 = psi cap on=20 that and it goes up some more.

If coolant=20 and lubricant failure are the criteria for = establishing redline=20 temps,  my post of the other day = is=20 valid.

I think = 210-220=20 degree temps should be good running temps, not redlines. Modern (Post = model A)=20 engines run more efficiently at those=20 temperatures.

But I'd = still like to=20 hear an opinion from a 13b authority or two if there are other = criteria for=20 coolant and oil temperature limits.

FWIW,=20 again,

Jack=20 Ford

----- Original Message = -----=20

From: Dale=20 Smith

To: Rotary motors in = aircraft=20

Sent: Friday,=20 July 16, 2004 4:18 PM

Subject:=20 [FlyRotary] Re: 11th test flight

 

Steve=20 Brooks wrote:

I made a test flight today with the new scoop, =
but also wit cooler OAT (70F)
than I've seen in the last couple weeks.  I flew for 6 tenths of an =
hour
with temperatures for the oil at 207 and =
coolant 200 stabilized at 4700
RPMs.  =
I increased the throttle to 5300 RPMs and the coolant stayed put, =
and
the oil increased by only 3 degrees.  I was about 1500 AGL for the =
entire
flight. I did descend a few hundred feet and =
climb a few hundred feet to
watch the temperatures, but usually was flying =
a level circle around the
airport.  I reduced the throttle to 4300, and maintained level =
flight at
about 105 kts.  Oil dropped to 195 and coolant to =
190.
 
I guess that the good news is the I could fly =
all day at those temperatures,
and I never saw any temperatures higher than =
210, though I really didn't do
an extended climb.  I really didn't push level cruise higher than 5300 =
(135
kts), but the temperatures seemed to be =
holding, and actually the oil
dropped a degree after letting it stabilize a =
couple of minutes.
 
The bad news is that the scoop appears to be =
costing me about 10 kts, which
I was expecting.  I also don't have any wheel pants yet on the main =
gear, so
it's not like I'm out to win any speed test at =
this point anyways.  My =
oil
continues to run higher =
than the coolant which indicates to me that I =
need
to do some more baffling to =
divert more air to the oil =
cooler.
 
I also have not done any filling or finishing =
to the scoop, so it's surface
is more like sandpaper right now.  Finishing it will probably =
improve air
flow some more, and also reduce some of the =
drag.   I left the =
scoop on the
plane for now, so that I can hopefully get =
another flight in tomorrow
morning.  My plan tomorrow is to climb up to 5000' and see what =
I get there.
Then I'll remove the scoop, which takes about =
5 minutes, and bring it home
for some filling and sanding.  And after a few more flights, =
and more
filling and sanding, some primer and =
paint.
 
I am still looking at this as a "hot weather =
scoop".  My plan is to =
remove
it during cool weather, and re-install it for =
June-August.  I mount =
the
scoop using 6 10-32 SS screws into nutplates =
embedded in the landing gear
cover, plus 2 of the screws that mount the =
landing gear cover to the
fuselage.  It's not likely to come off on its =
own.
 
Steve =
Brooks
Cozy MKIV
Turbo Rotary - 6.3 hours and =
counting
 
  =

Steve=20 ... re: the above underlined.

I would say that what you = have is=20 just fine regarding your oil temp.  Remember that the "delta T" = between=20 where you are running and the temperature at where it quits working is = quite=20 high.  Especially if you are using synthetic oil.   = Molbil I=20 keeps lubricating quite well up past 400 degrees and = beyond.   =20 Thus, if you are running temps near 200 degrees you have near a 200 = degree=20 temp spread (delta T) between what the oil can take away and what it = IS taking=20 away in BTU's of heat dissipation in a stable = system.    That=20 is a pretty fat safety margin, when you figure you can run 100 degrees = hotter=20 than what you are now and still have 100 degrees left before = lubrication=20 failure is imminent.  Obviously, lower is better.

Water = cooling=20 now is a different story.   operating coolant at temps near = 200=20 while water boils at 212 ... gives you a delta T of just 12 degrees to = play=20 with.   I know you can kick it up by anti-freeze, pressure = on the=20 system, etc. etc.   but the bottom line is that you have a = lot=20 narrower delta T range to deal with, and you are always working the = system a=20 lot closer to near it's maximum potential for heat = dissipation.

Just a=20 thought,

Dale=20 Smith

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