X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from wr-out-0506.google.com ([64.233.184.227] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2360475 for flyrotary@lancaironline.net; Sun, 30 Sep 2007 10:09:39 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.233.184.227; envelope-from=msteitle@gmail.com Received: by wr-out-0506.google.com with SMTP id 76so1543739wra for ; Sun, 30 Sep 2007 07:09:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; bh=tw4R0YQdSLjVnzYk9HJ13SXenMxTOpZgjQK5o0y6sfA=; b=FP2FJgMFF3VZqVWxfYsRv6ZbMBhFlxVjNlp2D7cZ50njnE+Z6JvbjKElbQB1I0xegCosw1ziVGgIeZYZiKtPP7krroCV9ky48FBPXLd3gK4dqcuGfgO5Oct5FH1QdIKw0alM/jUB7bzvD0t2VzbuDBcXw3Swf4QJ5v1QqWqhtlQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=fNrxc7CTVsvk6el7RFrFixnVdrtxJ/GNgGuw+MQwOeGOaXDVNQM4rK3pAs/yF8kHatCT/5zqq1OaqKfcXLgXpxXUo7cU68ZzJcqetwrApvPDnDosVhvbnsC+OBgfHCZ9oVXWDLsRDXvuEajaJwxd9cptB8RcjMQM85LSsvJrbFI= Received: by 10.90.91.14 with SMTP id o14mr1120019agb.1191161342183; Sun, 30 Sep 2007 07:09:02 -0700 (PDT) Received: by 10.90.35.16 with HTTP; Sun, 30 Sep 2007 07:09:02 -0700 (PDT) Message-ID: <5cf132c0709300709y37abfc92wa6b936da2a6108eb@mail.gmail.com> Date: Sun, 30 Sep 2007 09:09:02 -0500 From: "Mark Steitle" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Oil Delta - T In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_6884_1660548.1191161342167" References: ------=_Part_6884_1660548.1191161342167 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Ed, Yes, I'm happy with the coolant temps. I wish the oil would allow a little more margin, but 190* @ 5200 is ok for 90* OAT. I'll be gong out to the airport in a while and I'll check the calibration on the coolant sensors. Mark Overcast with 40% chance of rain today. :-( On 9/30/07, Ed Anderson wrote: > > I suspect that you temp sensor location may be the problem rather than > calibration. If its outside the main flow channel, then its hard to tell > just how close or far off of the main flow temps it may be registering. > > On the other hand if your coolant engine outlet temp is measuring only > 161F (and assuming that is somewhere near the actual temp) then you radiator > is clearly doing its job by cooling down the coolant before it enters the > engine. When I am cruising at 5400 rpm my coolant temps range from > 155F-175F depending on OAT. This is temp out of the engine. Since your > temp is in the same ball park, it appears your radiator is doing a good job > especially given the 90F OAT. > > > > Ed > > ----- Original Message ----- > *From:* Mark Steitle > *To:* Rotary motors in aircraft > *Sent:* Saturday, September 29, 2007 10:13 PM > *Subject:* [FlyRotary] Re: Oil Delta - T > > > Ed, > OK, I'll recallibrate the sensors ONE MORE TIME! They were reading within > a degree of each other before I relocated one of them. I did take the time > to verify the EC-2 sensor was reading correctly at 212* during the switch. > But I didn't check it lower than that. I'll use ambient temp for a low > reference. > > I suspect the problem may be where one of the sensors is located. The > first sensor is located on the WP housing at the outlet from the engine. > Since that is one of the factory locations, I don't see any problem there. > The second sensor is on the WP housing inlet, but not on the main line, it > is on the one returing from the swirl tank, but is very close to where the > main WP inlet is located. It is fed by a line that runs through the swirl > tank from the outlet side of the radiator, but at the top instead of the > bottom (to draw any air out of the radiator). Directly across from this > fitting is the "hot" inlet to the radiator. I'm sure that some of the > coolant goes straight across the core to the swirl tank fitting. (Yes, this > is confusing me too) I questioned the wisdom of putting the sensor where I > did, but did it anyway due to the ease of installation (No draining the > cooling system, no drilling, no tapping). Anyway, this was supposed to be a > "temporary" test setup. > > So, it looks like I probably need to find a better place to locate the > second sensor. I'll check the accuracy of this sensor at around 150* and > see what it shows. If there is a significant error, I'll dive into the EC-2 > calibration system one more time (heaven help me). > > Mark > > > On 9/29/07, Ed Anderson wrote: > > > > Mark, if you really had excess air flowing through your radiators the > > coolant would drop more than 4 Deg F. In fact, the more air flow the more > > coolant Delta T you would drop through the radiator. So if you had > > something like 180F in and 120F out then I might suspect too much air flow > > through the cores, but not with a drop of only 4 deg F. In fact if that > > delta T is correct (which I suspect it is not), then you would need > > tremendous coolant flow rates for it to carry away the engine heat it needs > > to at 5200 rpm. > > > > I did some back of envelope calculations. > > > > IF your coolant flow was 30 GPM at 8.25 lb/gal coolant with a 0.65(50/50 mix) Cp, then a 4 degreeF drop in coolant temp would only be getting > > rid of 644 BTU/Min. > > > > At 5200 rpm and a 19:1 A/F ratio you would need to get rid of approx > > 3100 BTU/Min through your radiator. I suspect that the 4 degree drop you > > are measuring may be in error. I assume you are measuring temp at radiator > > inlet (engine outlet) and radiator outlet (or engine inlet) It would take > > something like a 20 deg coolant temp drop at 30 GPM flow or a flow rate of > > 150 GPM at 4 deg drop to get rid of that much heat. > > > > On the other hand if you were flowing 60 gpm of pure water and had a > > 6.5F drop that would get rid of the required BTUs. I have no clue as to > > the flow rate of a 20B water pump, but suspect my guess of 60 gpm might be > > on the high side. > > > > Since you are apparently cooling just fine with the radiators, then : > > > > 1. My calculations are incorrect > > 2. Your coolant temp drop is more than 4 Fdeg > > 3. your flow rate is >50 gpm > > 4. You oil system is dumping the excess heat that your radiators are > > not getting rid of. > > > > FWIW > > > > Ed > > > > > > > > ----- Original Message ----- > > *From:* Mark Steitle > > *To:* Rotary motors in aircraft > > *Sent:* Saturday, September 29, 2007 7:51 PM > > *Subject:* [FlyRotary] Re: Oil Delta - T > > > > > > Tracy, > > > > I flew again today. I'm still staying very close to the airport and was > > forced to limit my altitude to 2500' due to clouds. OAT was about 90* and > > oil got to 215, but came right down after leveling off and settled in at > > 190*. The strange thing is the water temps in economy cruise (5200 engine > > rpm, 1800 prop rpm) were in the 157* range. I'm measuring water temp in and > > out. Water out was about 161*, so I'm getting very little temp drop through > > the radiator. We're figuring that this is probably due to too much air to > > the water radiator or too rapid coolant flow through the radiator (I'm > > running the 20B pump). My main pulley has been downsized, but I may also > > need to enlarge the wp pulley a little to slow the flow. I'm considering > > doing a quick mod to check this theory. If that's true, then my oil temps > > should drop because I suspect airflow through the two radiators are fighting > > for the exit space and the water radiator is winning. > > > > Mark > > > > > > On 9/29/07, Tracy Crook wrote: > > > > > > Haven't had any 100+ days since installing the Renesis but cooling is > > > similar to the 2nd gen I had a few years ago when we had 10 consecutive days > > > of 100+ temps. Didn't have to wait it out but simply limited power after > > > initial climbout. Still had more ROC than most certified planes at the > > > reduced power setting. I start with around 2500 FPM on a standard day and > > > never had to settle for less than ~1000 fpm due to heat issues. > > > > > > Hope my 20B RV-8 does as well or better but I will install spray bar > > > for initial tests. > > > > > > Tracy (delayed 20B test schedule due to motorcycle distraction) > > > > > > > > > On 9/27/07, Mark Steitle wrote: > > > > > > > > Tracy, > > > > > > > > So, what do you call a "hot" day? In Austin, it is normal during > > > > the summer for temps to be in the upper 90's and even above 100 on > > > > occasion. I don't want to be grounded waiting for the Texas heat to > > > > subside. I guess I could install a spray bar for summer flying. Right now > > > > I can keep temps in the green up into the low 90's. Living in Texas, I > > > > would like a little more margin than that. Not everyone can swing a summer > > > > home in Colorado. ;-) > > > > > > > > Mark S. > > > > (Just happy to be flying again.) > > > > > > > > > > > > > > > > > > > > On 9/26/07, Tracy Crook wrote: > > > > > > > > > > Engine will cool at any throttle setting that enables the plane to > > > > > fly. The coolant & oil temp curve looks about like the power required curve > > > > > of the airframe, minumum at around 95 mph and rises on either side of that > > > > > speed. Only exception is WOT at Vx on hot day. Engine will exceed redline > > > > > temps if this is maintained more than a minute or so. Fortunately there is > > > > > never any real need to do that. > > > > > > > > > > Tracy > > > > > > > > > > > > > > > On 9/26/07, Mark Steitle wrote: > > > > > > > > > > > > Tracy, > > > > > > > > > > > > Is there a particular speed that you must reach before your > > > > > > system cools? > > > > > > > > > > > > Mark > > > > > > > > > > > > > > > > > > > > > > > > On 9/26/07, Tracy Crook wrote: > > > > > > > > > > > > > > For another data point, the delta T on oil cooler depends on > > > > > > > power setting on my installation (no big surprise). It is around 40 degrees > > > > > > > F at higher power settings. > > > > > > > > > > > > > > Tracy > > > > > > > > > > > > > > > > > > > > > On 9/18/07, Mark Steitle wrote: > > > > > > > > > > > > > > > > For those that are flying (rotaries), I'm curious as to what > > > > > > > > delta-T you're seeing across the oil cooler. And at what speed you attain > > > > > > > > adequate cooling. > > > > > > > > > > > > > > > > Mark S. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ------=_Part_6884_1660548.1191161342167 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
Ed,
Yes, I'm happy with the coolant temps.  I wish the oil would = allow a little more margin, but 190* @ 5200 is ok for 90* OAT.  I'= ll be gong out to the airport in a while and I'll check the calibration= on the coolant sensors.
 
Mark
Overcast with 40% chance of rain today.  :-(


 
On 9/30/07, = Ed Anderson <eanderson@= carolina.rr.com> wrote:
I suspect that you temp sensor location may be th= e problem rather than calibration.  If its outside the main flow chann= el, then its hard to tell just how close or far off of the main flow temps = it may be registering.  =20
 
On the other hand if your coolant engine outlet t= emp is measuring only 161F (and assuming that is somewhere near the actual = temp) then you radiator is clearly doing its job by cooling down the coolan= t before it enters the engine.  When I am cruising at 5400 rpm my cool= ant temps range from 155F-175F depending on OAT.  This is temp out of = the engine.  Since your temp is in the same ball park, it appears your= radiator is doing a good job especially given the 90F OAT. =20
 
 
 
Ed
----- Original Message -----
From: Mark Steitle=
Sent: Saturday, September 29, 2007 1= 0:13 PM
Subject: [FlyRotary] Re: Oil Delta -= T

 
Ed,
OK, I'll recallibrate the sensors ONE MORE TIME!  They were r= eading within a degree of each other before I relocated one of them.  = I did take the time to verify the EC-2 sensor was reading correctly at 212*= during the switch.  But I didn't check it lower than that.  = I'll use ambient temp for a low reference. =20
 
I suspect the problem may be where one of the sensors is located.=   The first sensor is located on the WP housing at the outlet from the= engine.  Since that is one of the factory locations, I don't see = any problem there.  The second sensor is on the WP housing inlet, but = not on the main line, it is on the one returing from the swirl tank, but is= very close to where the main WP inlet is located.  It is fed by = a line that runs through the swirl tank from the outlet side of the ra= diator, but at the top instead of the bottom (to draw any air out of the ra= diator).  Directly across from this fitting is the "hot" inl= et to the radiator.  I'm sure that some of the coolant goes straig= ht across the core to the swirl tank fitting. (Yes, this is confusing me to= o)  I questioned the wisdom of putting the sensor where I did, but did= it anyway due to the ease of installation (No draining the cooling system,= no drilling, no tapping).  Anyway, this was supposed to be a "te= mporary" test setup. =20
 
So, it looks like I probably need to find a better place to locate the= second sensor.  I'll check the accuracy of this sensor at ar= ound 150* and see what it shows.  If there is a significant error, I&#= 39;ll dive into the EC-2 calibration system one more time (heaven help me).=    =20
 
Mark 

 
On 9/29/07, = Ed Anderson <eanderson@= carolina.rr.com > wrote:=20
  Mark, if you really had excess air fl= owing through your radiators the coolant would drop more than 4 Deg F. = ; In fact, the more air flow the more coolant Delta T you would drop throug= h the radiator.  So if you had something like 180F in and 120F out the= n I might suspect too much air flow through the cores, but not with a drop = of only 4 deg F.   In fact if that delta T is correct (which I su= spect it is not), then you would need tremendous coolant flow rates for it = to carry away the engine heat it needs to at 5200 rpm.=20
 
 I did some back of envelope calculations.&n= bsp;
 
 IF your coolant flow was 30 GPM at 8.25 lb/= gal coolant with a 0.65 (50/50 mix) Cp, then a 4 degreeF drop in coolant te= mp would only be getting rid of 644 BTU/Min. 
 
 At 5200 rpm and a 19:1 A/F ratio you would = need to get rid of approx 3100 BTU/Min through your radiator.  I suspe= ct that the 4 degree  drop you are measuring may be in error.  I = assume you are measuring temp at radiator inlet (engine outlet) and ra= diator outlet (or engine inlet)   It would take something like a = 20 deg coolant temp  drop at 30 GPM flow or a flow rate of 150 GPM at = 4 deg drop to get rid of that much heat.  =20
 
On the other hand if you were flowing 60 gpm of p= ure water and had a 6.5F drop that would get rid of the required BTUs. = ; I have no clue as to the flow rate of a 20B water pump, but suspect my gu= ess of 60 gpm might be on the high side.=20
 
Since you are apparently cooling just fine with t= he radiators, then :
 
1.  My calculations are incorrect
2.  Your coolant temp drop is more than 4 Fd= eg
3.  your flow rate is >50 gpm
4.  You oil system is dumping the excess hea= t that your radiators are not getting rid of.
 
FWIW
 
Ed
 
 
----- Original Message -----
From: Mark Steitle=
Sent: Saturday, September 29, 2007 7= :51 PM
Subject: [FlyRotary] Re: Oil Delta -= T

 
Tracy,
 
I flew again today.  I'm still staying very close to the airp= ort and was forced to limit my altitude to 2500' due to cloud= s.  OAT was about 90* and oil got to 215, but came right down after le= veling off and settled in at 190*.  The strange thing is the water tem= ps in economy cruise (5200 engine rpm, 1800 prop rpm) were in the 157* rang= e.  I'm measuring water temp in and out.  Water out was about= 161*, so I'm getting very little temp drop through the radiator. = We're figuring that this is probably due to too much air to the w= ater radiator or too rapid coolant flow through the radiator (I&#= 39;m running the 20B pump).  My main pulley has been downsized, but&nb= sp;I may also need to enlarge the wp pulley a little to slow the flow.=  I'm considering doing a quick mod to check this theory.  If= that's true, then my oil temps should drop because I suspect airflow t= hrough the two radiators are fighting for the exit space and the water radi= ator is winning. =20
 
Mark

 
On 9/29/07, = Tracy Crook <tracy@rotar= yaviation.com=20 > wrote:=20
Haven't had any 100+ days since installing the Renesis but cooling= is similar to the 2nd gen I had a few years ago when we had 10 consec= utive days of 100+ temps.  Didn't have to wait it out but simply l= imited power after initial climbout.  Still had more ROC than most cer= tified planes at the reduced power setting.  I start with around 2500 = FPM on a standard day and never had to settle for less than ~1000 fpm due t= o heat issues.=20
 
Hope my 20B RV-8 does as well or better but I will install spray bar f= or initial tests.
 
Tracy (delayed 20B test schedule due to motorcycle distraction)
 
On 9/27/07, = Mark Steitle <msteitle@gmail.c= om > wrote:=20
Tracy,
 
So, what do you call a "hot" day?  In Austin, it is nor= mal during the summer for temps to be in the upper 90's and even above = 100 on occasion.  I don't want to be grounded waiting for the Texa= s heat to subside.  I guess I could install a spray bar for summer fly= ing.  Right now I can keep temps in the green up into the low 90's= .  Living in Texas, I would like a little more margin than that.&= nbsp; Not everyone can swing a summer home in Colorado. = ;  ;-)=20
 
Mark S.
(Just happy to be flying again.)
 


 
On 9/26/07, = Tracy Crook <tracy@rotar= yaviation.com=20 > wrote:=20
Engine will cool at any throttle setting that enables the plane to fly= .  The coolant & oil temp curve looks about like the power require= d curve of the airframe, minumum at around 95 mph and rises on either side = of that speed.  Only exception is WOT at Vx on hot day.  Engine w= ill exceed redline temps if this is maintained more than a minute= or so.   Fortunately there is never any real need to do tha= t. =20
 
Tracy

 
On 9/26/07, = Mark Steitle <msteitle@gmail.c= om > wrote:=20
Tracy,
 
Is there a particular speed that you must reach before your system coo= ls? 
 
Mark


 
On 9/26/07, = Tracy Crook <tracy@rotar= yaviation.com=20 > wrote:=20
For another data point, the delta T on oil cooler depends on power set= ting on my installation (no big surprise).  It is around 40 degrees F = at higher power settings.
 
Tracy

 
On 9/18/07, = Mark Steitle <msteitle@gmail.c= om > wrote:=20
For those that are flying (rotaries), I'm curious as to what delta= -T you're seeing across the oil cooler.  And at what speed you&nbs= p;attain adequate cooling.
 
Mark S.








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