X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-bw0-f226.google.com ([209.85.218.226] verified) by logan.com (CommuniGate Pro SMTP 5.3c4) with ESMTP id 4032628 for flyrotary@lancaironline.net; Sun, 20 Dec 2009 19:40:42 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.218.226; envelope-from=msteitle@gmail.com Received: by bwz26 with SMTP id 26so3410146bwz.27 for ; Sun, 20 Dec 2009 16:40:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=qOQ/kBcCKh0LqFokRzOZj/UWqaHIkJ1GPVvFduY/xTA=; b=Z4Cs0XvkCkaHbGuc0RGr0qxmF1BY/Cei5rT/+dBiaX8Haw1jDCL6DlO0AtxVq416ZI HJ0d0zMzjyCajIZ8/sSmp/AuWGJhUIaJsVKG5DD5A0s43lvvN/jjK9ef59KnmyMWX0Xo ZBb06+OynAVB8xMSSjJUwjB+ZSr6M2EI8i7xc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=omoqbVnOUQFm0S1bKgjVNMr77KZzScrjvfn/v+MnvqzYw0UUoDIr2P1KeqIKAgipqs RPGtzVK99xfWCEUCiLkM6k1q00FIECyuQZUZ9Cv6YZMVvongqjJZfLurvRPz66nDxJqz MNR/p0xKGGIt1QPrNuGcl1mHfMne5ydY+1UDg= MIME-Version: 1.0 Received: by 10.204.10.136 with SMTP id p8mr4289080bkp.56.1261356006398; Sun, 20 Dec 2009 16:40:06 -0800 (PST) In-Reply-To: References: Date: Sun, 20 Dec 2009 18:40:06 -0600 Message-ID: <5cf132c0912201640g96740d1nd4c910d06b1ab69f@mail.gmail.com> Subject: Re: [FlyRotary] Re: Oil Cooling From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=000325559a7eb25a60047b32543d --000325559a7eb25a60047b32543d Content-Type: text/plain; charset=ISO-8859-1 "You are an inspiration for me. Now I'll go check my oil lines...!!!" This should be an inspiration to everyone!!! Mark S. On Sun, Dec 20, 2009 at 6:07 PM, wrote: > WoW Tracy! > How much excitement does it take to keep you happy? > While you were doing that "Sky Writting" I was enjoying a nice mundane > second 20 minute ground run. This time I upped the RPM to 2850, which was > about 17.1 "Hg. The water temp stabilized about 158F and the oil about 179F. > I'm getting a bit better at scrolling thru the EM2 for data, but I need to > write it down while it's happening. The memory fades fast. I seem to recal > 22% power. EGT 1450F > I'm just at 1 running hour. I'm using 10/30 oil for break-in. 60 PSI @ > 2850 RPM 179F. I suppose I'll dump it soon. Can synthetic oil be used for > break-in? > You are an inspiration for me. Now I'll go check my oil lines...!!! > > -----Original Message----- > From: Tracy Crook > To: Rotary motors in aircraft > Sent: Sun, Dec 20, 2009 2:57 pm > Subject: [FlyRotary] Re: Oil Cooling > > I was ready to flight test the new oil cooler installation this morning (or > thought I was). OAT was only 41 deg and it took a long idle time to warm > up so used that time to check for oil leaks and saw no signs. The pattern > of oil and water temps looked good so I had high hopes. Watched temps > during takeoff run and continued to see good numbers. Climbed out to 500 ft > and turned left to downwind and thought I smelled a slight whiff of hot > oil. Looked over my shoulder and saw that I was sky-writing with a dense > smoke trail so throttled back to high idle and did a hard 360 to the right > to setup for a downwind landing (almost no wind). The only thing new was > the oil cooler so I was scolding myself for installing this cheap POS and > monitoring the oil pressure to see if this was going to cost me an engine > overhaul. Pressure stayed at 55 - 60 PSI all through the landing so its > OK. The oil cooking off the exhaust system did not ignite. Wonder if the > poor burning qualities of synthetic oil is another good reason to use it? > > On the ground it looked like there was a couple of quarts of Mobile 1 > dripping off the bottom of fuselage and left wing trailing edge. Popped > the cowl top and the entire engine compartment is drenched in oil EXCEPT for > the oil cooler core itself which is dry. The cooler turned out to be OK. > The leak was from the bottom fitting on the cooler. It came equipped with > -10 male fittings so I had installed -10 to -8 adapters to match the -8 > hoses in the plane. The tightening procedure needed on these adapters had > some pitfalls. I am always careful to use two wrenches on these fittings so > as not to put torque on the cooler and damage it. These adapters require > that the adapter be put on first using the two wrench method followed by the > hose fitting to the adapter. BUT, one wrench needs to remain on the oil > cooler fitting and the other on the hose fitting. I mistakenly put one on > the adapter and one on the hose fitting. This results in loosening the > adapter to cooler mating thread as you tighten the hose fitting. That's > where the oil was coming from. > > Although this was a very brief flight on a cool day, I could tell from the > trend on the oil & water temps that this cooler was going to work much > better than the old one even though it is about 25% smaller in volume. Size > really isn't everything. > > I properly installed the adapters and hose fittings and tested for leaks > (none found) but didn't have enough daylight left for another flight test. > Will try again tomorrow. > > Noticed one other oddity during this test. As soon as the O2 sensor got > covered in oil, it quit working. These sensors actually have to 'see' the > outside air at the cold end of the sensor. They compare the O2 in the air > to the O2 in the exhaust and stop working when they can't. > > Tracy > > > On Sun, Dec 20, 2009 at 4:58 PM, wrote: > >> I've been reading everything I could on cooling after my first attempt >> flopped. Today I got my new cooling set up complete enough to ground test. I >> copied (my version) from several of you, notably Dave Leonard's radiator and >> Tracy's RV-4 oil cooler. Hat's off to Ed Anderson for all the under cowl >> duct work on his website too. >> I did achieve the stable temps at low power that Dave L told me are >> critical. I just now got done running my RV-8 13B turbo for over 20 minutes >> and got stabilized temps of 140F water and 170F oil. Once the oil cooler >> thermostat opened, the temps dropped a few degrees. >> Outside air temp 53F, 81% RH. Perhaps I should have run it longer, but >> worries about leaks, fires etc. always make inspections prudent. >> I suppose I have overcooled my plane, and added a big drag bucket on the >> chin, but hopefully it will be safe to fly, and I can work back from 'too >> cool' for more speed later. >> After reading Tracy's post about adding the oil cooler exit duct, and >> different flow resistance of the two coolers, I am glad I devided the two. >> What I think lead to any success I might be having, is that I devided the >> air suppies and outlets. The oil cooler gets 100% of the right cowl cheek >> air, and the heated air exits the right side of the cowl. The radiator gets >> air from the highest pressure point on the airframe: under the prop spinner. >> I left out the upper lip because I believe this area has attached laminar >> flow. The radiator exit air passes out the cowl bottom in the usual way. >> The left cowl cheek is for Engine intake, plus surface cooling air on the >> engine, turbo, & fuel system. It shares the bottom outlet with the radiator >> air. I'm still working out the this duct. >> . >> >> -----Original Message----- >> From: Tracy Crook >> To: Rotary motors in aircraft >> Sent: Sat, Dec 19, 2009 5:46 pm >> Subject: [FlyRotary] Re: Oil Cooling >> >> In retrospect it does seem obvious but I had never thought about matching >> the airflow characteristics of the water and oil heat exchangers before. I >> should know by tomorrow if this is just wishful thinking. >> >> Those heat exchanger volume figures you mentioned are at best just a rule >> of thumb but still useful. Other details can make a world of difference. >> For example, my RV-4 has had the same cooling components since day one but >> cooling on that first flight looked hopeless. Now it is fine on even the >> hottest days. Heat exchanger size isn't everything. >> >> My 20B has significantly less than 1.5 times the core volume of my 13B >> installation. I'm hoping that better diffusers and other details will make >> up for the relatively smaller heat exchangers. >> >> I can't think of any reason why the 20B would need more than 1.5 times the >> 13Bs cooling requirement if all other factors are the same. That's a big if >> of course. >> >> Tracy >> >> >> On Sat, Dec 19, 2009 at 7:15 PM, George Lendich wrote: >> >>> Tracy, >>> All that makes perfect sense and leads me to a question which has more >>> curiosity value than anything else. What actual size did you settle on for >>> the 20B. I'm curious to know if the 20B requires more cooling than 1.5 times >>> a 13B. >>> >>> Calculating the ( rule of thumb) radiator size of approx 600 cu" for >>> 200hp, giving 3 cu" per HP, the size of the Mazda oil cooler then gives a .8 >>> per cu" per hp. I wondering if this holds true for the 20B and indeed the >>> single rotor. >>> George ( down under) >>> >>> Just an update on my RV-8 / 20B oil cooling experiments. >>> >>> On the theory that airflow patterns inside the cowl were blocking airflow >>> through oil cooler, I installed a partial exit duct behind the radiator >>> directing the airflow downward toward the cowl outlet. It looked very >>> restrictive but flight tests showed almost no affect on water cooling (which >>> is OK) but a significant improvement in oil cooling. I further restricted >>> the airflow through the rad by putting some roof ridge vent material inside >>> the inlet diffuser. This gave a tiny increase in water temp but a further >>> improvement in oil cooling. Long story short, after several more tests it >>> became apparent that back pressure under the cowl was having a major effect >>> on the oil cooling. I have no idea why my instrument did not read the >>> pressure correctly. It works fine on the bench and is properly referenced >>> to the static system in the plane. The temptation is to keep changing the >>> cooling outlet scheme until the internal cowl back pressure is low enough to >>> get the cooling good enough. My belief is that this would lead to a very >>> high drag solution. You may remember the experiment I did by flying with >>> the cowl removed. The cooling was never a problem then (except perhaps too >>> much cooling) but the drag was enormous. The fuel burn was 60% higher at >>> the test airspeed of 130 mph. >>> >>> The conclusion I eventually came to was that the rad (because of it's >>> relatively low air flow resistance) is hogging the airflow capability of the >>> cowl cooling outlet. (cowl flap did not have enough effect to fix the >>> problem). Keep in mind that the oil cooler is a thick AC evaporator core >>> that is very restrictive. The current experiment is to replace it with a >>> much less restrictive (to airflow) oil cooler. I found the largest cooler >>> that would fit in the same location as the AC core and I'm using the same >>> diffuser as before (slightly modified to fit the larger face of the new >>> cooler). This cooler is only 2" thick and core volume is 30% less than the >>> AC core. It is slightly larger in volume than an RX-7 cooler. Without any >>> back pressure (flying with cowl off), the AC core had way more than enough >>> cooling capacity (146 F oil temp on a 93 degree day) so I'm hoping that this >>> smaller cooler will be enough. Should be ready to flight test it this week. >>> >>> I should point out another symptom. Power setting (and therefore >>> airspeed) had very little effect on the cooling (i.e., it didn't get much >>> hotter at high power as long as airspeed went up as well. Things got hot >>> fast in climb however. This also indicated to me that cooling was limited >>> by airflow through the system rather than by the oil cooler's ability to >>> transfer the heat to the air. If the cooler is simply too small, more >>> airflow will not help much. >>> >>> Tracy >>> >> >> > --000325559a7eb25a60047b32543d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
"You are an inspiration for me. Now I'= ;ll go check my oil lines...!!!"
=A0
This should be an inspiration to everyone!!!
=A0
Mark S.


=A0
On Sun, Dec 20, 2009 at 6:07 PM, <shipchief@aol.com> wrote:
WoW Tracy!
How much excitement does it take to keep you happy?
While you were doing that "Sky Writting" I was enjoying a ni= ce mundane second 20 minute ground run. This time I upped the RPM to 2850, = which was about 17.1 "Hg. The water temp stabilized about 158F and the= oil about 179F. I'm getting a bit better at scrolling thru the EM2 for= data, but I need to write it down while it's happening. The memory fad= es fast. I seem to recal 22% power. EGT 1450F
=A0I'm=A0just at 1 running hour. I'm using 10/30 oil for break= -in. 60 PSI @ 2850 RPM 179F. I suppose I'll dump it soon. Can synthetic= oil be used for break-in?
You are an inspiration for me. Now I'll g= o check my oil lines...!!!
=A0
= -----Original Message-----
From: Tracy Crook <tracy@rotaryaviation.com>
= To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sun, Dec 20, 2009 2:57 pm
Subject: [FlyRotary] Re: Oil Cooling
=
I was ready to flight test the new oil cooler installation this mornin= g (or thought I was).=A0=A0 OAT was only 41 deg and it took a long idle tim= e to warm up so used that time to check for oil leaks and saw no signs.=A0 = The pattern of oil and water temps looked good so I had high hopes.=A0 Watc= hed temps during takeoff run and continued to see good numbers. Climbed out= to 500 ft and turned left to downwind and thought I smelled a slight whiff= of hot oil.=A0 Looked over my shoulder and saw that I was sky-writing with= a dense smoke trail so throttled back to high idle and did a hard 360 to t= he right to setup for a downwind landing (almost no wind).=A0=A0 The only t= hing new was the oil cooler so I was scolding myself for installing this ch= eap POS and monitoring the oil pressure to see if this was going to cost me= an engine overhaul.=A0 Pressure stayed at 55 - 60 PSI all through the land= ing so its OK.=A0=A0 The oil cooking off the exhaust system did not ignite.= =A0 Wonder if the poor burning qualities of synthetic oil is another good r= eason to use it?

On the ground it looked like there was a couple of quarts of Mobile 1 d= ripping off the bottom of fuselage and left wing trailing edge. =A0 Popped = the cowl top and the entire engine compartment is drenched in oil EXCEPT fo= r the oil cooler core itself which is dry.=A0 The cooler turned out to be O= K.=A0 The leak was from the bottom fitting on the cooler.=A0 It came equipp= ed with -10 male fittings so I had installed -10 to -8 adapters to match th= e -8 hoses in the plane.=A0 The tightening procedure needed on these adapte= rs had some pitfalls.=A0 I am always careful to use two wrenches on these f= ittings so as not to put torque on the cooler and damage it.=A0 These adapt= ers require that the adapter be put on first using the two wrench method fo= llowed by the hose fitting to the adapter.=A0 BUT,=A0 one wrench needs to r= emain on the oil cooler fitting and the other on the hose fitting.=A0 I mis= takenly put one on the adapter and one on the hose fitting.=A0 This results= in loosening the adapter to cooler mating thread as you tighten the hose f= itting.=A0 That's where the oil was coming from.

Although this was a very brief flight on a cool day, I could tell from = the trend on the oil & water temps that this cooler was going to work m= uch better than the old one even though it is about 25% smaller in volume.= =A0 Size really isn't everything.

I properly installed the adapters and hose fittings and tested for leak= s (none found) but didn't have enough daylight left for another flight = test.=A0 Will try again tomorrow.=A0

Noticed one other oddity durin= g this test.=A0 As soon as the O2 sensor got covered in oil, it quit workin= g.=A0 These sensors actually have to 'see' the outside air at the c= old end of the sensor.=A0 They compare the O2 in the air to the O2 in the e= xhaust and stop working when they can't.=A0=A0

Tracy


On Sun, Dec 20, 2009 at 4:58 PM, <shipchief@aol= .com> wrote:
I've been reading everything I could on cooling after my first att= empt flopped. Today I got my new cooling set up complete enough to ground t= est. I copied (my version) from several of you, notably Dave Leonard's = radiator and Tracy's RV-4 oil cooler. Hat's off to Ed Anderson for = all the under cowl duct work on his website too.
I did achieve the stable temps at low power that Dave L told me are cr= itical. I just now got done running my RV-8 13B turbo for over 20 minutes a= nd got stabilized temps of 140F water and 170F oil. Once the oil cooler the= rmostat opened, the temps dropped a few degrees.
Outside air temp 53F, 81% RH. Perhaps I should have run it longer, but= worries about leaks, fires etc. always make inspections prudent.
I suppose I have overcooled my plane, and added a big drag bucket on t= he chin, but hopefully it will be safe to fly, and I can work back from = 9;too cool' for more speed later.
After reading Tracy's post about adding the oil cooler exit duct, = and different flow resistance of the two coolers, =A0I am glad I devided th= e two.
What I think lead to any success I might be having, is that I devided = the air suppies and outlets. The oil cooler gets 100% of the right cowl che= ek air, and the heated air exits the right side of the cowl. The radiator g= ets air from the highest pressure point on the airframe: under the prop spi= nner. I left out the upper lip because I believe this area has attached lam= inar flow. The radiator exit air passes out the cowl bottom in the usual wa= y.
The left cowl cheek is for Engine intake, plus surface cooling air on = the engine, turbo, &=A0fuel system. It shares the bottom outlet with th= e radiator air. I'm still working out the this duct.
.

= -----Original Message-----
From: Tracy Crook <tracy@rotaryaviation.com>
= To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sat, Dec 19, 2009 5:46 pm
Subject: [FlyRotary] Re: Oil Cooling
=
In retrospect it does seem obvious but I had never thought about match= ing the airflow characteristics of the water and oil heat exchangers before= .=A0 I should know by tomorrow if this is just wishful thinking.

Those heat exchanger volume figures you mentioned are at best just a rule o= f thumb but still useful.=A0 Other details can make a world of difference.= =A0 For example, my RV-4 has had the same cooling components since day one = but cooling on that first flight looked hopeless.=A0 Now it is fine on even= the hottest days.=A0 Heat exchanger size isn't everything.

My 20B has significantly less than 1.5 times the core volume of my 13B = installation.=A0 I'm hoping that better diffusers and other details wil= l make up for the relatively smaller heat exchangers.

I can't th= ink of any reason why the 20B would need more than 1.5 times the 13Bs cooli= ng requirement if all other factors are the same.=A0 That's a big if of= course.=A0

Tracy


On Sat, Dec 19, 2009 at 7:15 PM, George Lendich = <lendich@aanet.com.au> wrote:
Tracy,
All that makes perfect sense and leads= me to a question which has more curiosity value than anything else. What a= ctual size did you settle on for the 20B. I'm curious to know if the 20= B requires more cooling than=A01.5 times a 13B.
=A0
Calculating the ( rule of thumb) radia= tor size of approx=A0600 cu" fo= r 200hp, giving 3 cu" per HP,=A0the=A0size of the Mazda oil cooler the= n gives a .8 per cu" per hp. I wondering if this holds true for the 20= B and indeed the single rotor.
George ( down under)=A0

Just an update on my RV-8 /= 20B=A0 oil cooling experiments.=A0

On the theory that airflow patt= erns inside the cowl were blocking airflow through oil cooler, I installed = a partial exit duct behind the radiator directing the airflow downward towa= rd the cowl outlet.=A0 It looked very restrictive but flight tests showed a= lmost no affect on water cooling (which is OK)=A0 but a significant improve= ment in oil cooling.=A0=A0 I further restricted the airflow through the rad= by putting some roof ridge vent material inside the inlet diffuser.=A0 Thi= s gave a tiny increase in water temp but a further improvement in oil cooli= ng.=A0=A0 Long story short,=A0 after several more tests it became apparent = that back pressure under the cowl was having a major effect on the oil cool= ing.=A0=A0 I have no idea why my instrument did not read the pressure corre= ctly.=A0 It works fine on the bench and is properly referenced to the stati= c system in the plane.=A0=A0 The temptation is to keep changing the cooling= outlet scheme until the internal cowl back pressure is low enough to get t= he cooling good enough.=A0 My belief is that this would lead to a very high= drag solution.=A0 You may remember the experiment I did by flying with the= cowl removed.=A0 The cooling was never a problem then (except perhaps too = much cooling) but the drag was enormous.=A0 The fuel burn was 60% higher at= the test airspeed of 130 mph.

The conclusion I eventually came to was that the rad (because of it'= ;s relatively low air flow resistance) is hogging the airflow capability of= the cowl cooling outlet.=A0 (cowl flap did not have enough effect to fix t= he problem). =A0 Keep in mind that the oil cooler is a thick AC evaporator = core that is very restrictive.=A0=A0 The current experiment is to replace i= t with a much less restrictive (to airflow) oil cooler.=A0 I found the larg= est cooler that would fit in the same location as the AC core and I'm u= sing the same diffuser as before (slightly modified to fit the larger face = of the new cooler).=A0 This cooler is only 2" thick and core volume is= 30% less than the AC core.=A0 It is slightly larger in volume than an RX-7= cooler.=A0 Without any back pressure (flying with cowl off), the AC core h= ad way more than enough cooling capacity (146 F oil temp on a 93 degree day= ) so I'm hoping that this smaller cooler will be enough.=A0 Should be r= eady to flight test it this week.

I should point out another symptom. Power setting (and therefore airspe= ed) had very little effect on the cooling=A0 (i.e., it didn't get much = hotter at high power as long as airspeed went up as well.=A0=A0 Things got = hot fast in climb however.=A0 This also indicated to me that cooling was li= mited by airflow through the system rather than by the oil cooler's abi= lity to transfer the heat to the air.=A0 If the cooler is simply too small,= more airflow will not help much.=A0

Tracy



--000325559a7eb25a60047b32543d--