X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-03.southeast.rr.com ([24.25.9.102] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2093561 for flyrotary@lancaironline.net; Sat, 09 Jun 2007 13:44:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-03.southeast.rr.com (8.13.6/8.13.6) with SMTP id l59HiGoN009877 for ; Sat, 9 Jun 2007 13:44:16 -0400 (EDT) Message-ID: <000701c7aabe$6c7e1960$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Oil temp limit Date: Sat, 9 Jun 2007 13:48:43 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0004_01C7AA9C.E5275A10" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0004_01C7AA9C.E5275A10 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Good question, Al.=20 I have little hard data, but here are some of my conclusions. I believe the old coolant maximum temps were based on the early 13B = blocks using stock coolant O rings as the first limit. This was a = limit of around 210F. I believe that when we went the TES O rings that = temperature limit was moved up. I believe that the second limit is = coolant temps around the spark plug holes (excess temps causing cracks = in the housing). I don't know what the limit was based on that - = however, the racers found that by grooving the coolant passages in and = around the sparkplug are that much better heat removal was achieved. = My opinion (you know what that is worth) is that 210F on coolant is no = problem for any duration less than 30 minutes (perhaps even longer). I = have repeatedly had coolant up to 220F on take off (generally less than = 5 minutes) with no apparently adverse affects (at least no short term = ones). =20 The oil temps restriction I have a less of a handle on. 250F limit for = the oil pan sounds like a fairly high limit. I suspect that before we = started using the viton oil O rings (on the rotors) that those O rings = likely constituted a lower limit for oil. Apparently the rubber plugs = in the corner seals will go if the rotors get hot - but, not certain any = damage results. So the only temperature critical thing I can think of = on the rotors are those oil "O" rings. Now at some temperature point = the oil turns to water and no longer provides adequate bearing support - = but, I would assume synthetic oil raises that limit a bit. Here is some information I have found over the years Racing Beat Coolant (out of engine) maximum 210F Oil Out Of Cooler Maximum 200F Mazda Motor Sports Coolant (outlet Side) Maximum 205F Oil (Pan Temp) Maximum 250F (In the pan) From my own Personal Experience Maximum Ever Max ever on oil Temp 240F (first Flight) 4 1/2 Minute Duration so over = temp probably for 4 minutes Max ever on Coolant temp 240F(First Flight) . No damage detected = afterwards - except my seat cushion. These are some data points on take off and are generally less than 5 = minutes duration and frequently less than 3 minutes - after 120IAS is = achieved, temperatures start decreasing. Normally cruise burning 8 gph = is 165 oil, 165 Coolant. All coolant temps taken at thermostat housing, = all oil temps taken after oil cooler. Occasionally on 90F+ Days Oil temp 210F Coolant 220F Frequently on 70-90F days Oil temp 200F coolant 210 F Once OAT drops below 65F both oil and coolant stay at or below 200F on = max power take off, with the oil being around 190F and coolant 200F. For what its worth Ed ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Saturday, June 09, 2007 1:56 PM Subject: [FlyRotary] Oil temp limit I guess we've had this discussion before but to me it still seems like = a grey area. The limit has to do with temperature, time, and limiting component.=20 At typical cruise conditions I have coolant temps of 160-170F and oil = temps about 20 degrees higher. Short term climb out (1000 - 2000') I = see oil getting up 215 -220 and coolant around 200. If I continue = climb, I need to reduce power to keep them at those levels; which means = climb rates of 500-700 FPM with OAT of 65F, and maybe a bit less if OAT = is higher. I don't like being limited to that climb rate when I have = power for considerably more; but the real question is: Is that temp = level an issue if sustained for 10-15 minutes? And what is it affecting? I expect to make some modification to improve airflow through the = cooler, just deciding if it is urgent or if it can wait for another 10 = -20 hrs of flying. Anytime I go east from my airport I have to climb = from 1400' to about 7000' to clear high terrain. Thanks, Al ------=_NextPart_000_0004_01C7AA9C.E5275A10 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Good question, Al. 
 
I have little hard data, but here are some = of my=20 conclusions.
 
 I believe the old coolant maximum temps = were based=20 on the early 13B blocks using  stock coolant O rings as the first=20 limit.  This was a limit of around 210F.  I believe that when = we went=20 the TES O rings that temperature limit was moved up.  I believe = that the=20 second limit is coolant temps around the spark plug holes (excess temps = causing=20 cracks in the housing).  I don't know what the limit was based on = that -=20 however, the racers found that by grooving the coolant passages in and = around=20 the sparkplug are that much better heat removal was = achieved.   =20 My opinion (you know what that is worth) is that 210F on coolant is no = problem=20 for any duration less than 30 minutes (perhaps even longer).  I = have=20 repeatedly had coolant up to 220F on take off (generally less than 5 = minutes)=20 with no apparently adverse affects (at least no short term ones). =20
 
The oil temps restriction I have a less of a = handle=20 on.  250F limit for the oil pan sounds like a fairly high = limit.  I=20 suspect that before we started using the viton oil O rings (on the = rotors) that=20 those O rings likely constituted a lower limit for oil.  Apparently = the=20 rubber plugs in the corner seals will go if the rotors get hot - but, = not=20 certain any damage results.  So the only temperature critical = thing I=20 can think of on the rotors are those oil  "O" rings.  Now at = some=20 temperature point the oil turns to water and no longer provides adequate = bearing=20 support - but, I would assume synthetic oil raises that limit a=20 bit.
 
Here is some information I have found over the=20 years
 
Racing Beat
 
Coolant (out of engine) maximum = 210F
Oil Out Of=20 Cooler          Maximum=20 200F
 
Mazda Motor Sports
Coolant (outlet Side)  Maximum =20 205F
Oil (Pan=20 Temp)           = Maximum =20 250F (In the pan)
 
From my own Personal=20 Experience
 
Maximum Ever
Max ever on oil Temp = 240F (first=20 Flight) 4 1/2 Minute Duration so over temp probably for 4 = minutes
Max ever on Coolant temp = 240F(First=20 Flight) .  No damage detected afterwards - except my seat=20 cushion.
 
 
These are some data points on take off = and  are=20 generally less than 5 minutes duration and frequently less than 3 = minutes -=20 after 120IAS is achieved, temperatures start decreasing.  Normally = cruise=20 burning 8 gph is 165 oil, 165 Coolant.  All coolant temps taken at=20 thermostat housing, all oil temps taken after oil cooler.
 
Occasionally on 90F+ = Days
 
Oil temp 210F
Coolant 220F
 
Frequently on 70-90F=20 days
 
Oil temp 200F
coolant   210=20 F
 
Once OAT drops below 65F both oil and = coolant stay at=20 or below 200F on max power take off, with the oil being around 190F and = coolant=20 200F.
 
For what its worth
 
Ed
----- Original Message -----
From:=20 Al = Gietzen=20
Sent: Saturday, June 09, 2007 = 1:56=20 PM
Subject: [FlyRotary] Oil temp = limit

I guess we=92ve had = this=20 discussion before but to me it still seems like a grey = area.

 

The limit has to do = with=20 temperature, time, and limiting component.

 

At typical cruise = conditions I=20 have coolant temps of 160-170F and oil temps about 20 degrees higher.=20  Short term climb out (1000 =96 2000=92) I see oil getting up 215 = -220 and=20 coolant around 200.  If I continue climb, I need to reduce power = to keep=20 them at those levels; which means climb rates of 500-700 FPM with OAT = of 65F,=20 and maybe a bit less if OAT is higher.  I don=92t like being = limited to=20 that climb rate when I have power for considerably more; but the real = question=20 is: Is that temp level an issue if sustained for 10-15 minutes? And = what is it=20 affecting?

 

I expect to make some=20 modification to improve airflow through the cooler, just deciding if = it is=20 urgent or if it can wait for another 10 -20 hrs of flying. Anytime I = go east=20 from my airport I have to climb from 1400=92 to about 7000=92 to clear = high=20 terrain.

 

Thanks,

 

 Al

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