X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-iw0-f180.google.com ([209.85.214.180] verified) by logan.com (CommuniGate Pro SMTP 5.4c2) with ESMTPS id 4923045 for flyrotary@lancaironline.net; Sat, 26 Mar 2011 01:12:46 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.214.180; envelope-from=wdleonard@gmail.com Received: by iwn6 with SMTP id 6so3091318iwn.25 for ; Fri, 25 Mar 2011 22:12:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=F1U2NGfzZXrcxt29rrUJdmj+QwUkmuDhBLd0Qq29KIU=; b=rvHZlGeAs2apAQTZmObYvLWAuBP4oeFlyh1QGZlqWLKvIC3qucZGtf8LmWQMJuHFZ3 wrTenlf0O1pHG1Sz0AJOqfTxc7YkqeZm7fTex7Nz7QWyuYHJuAtHXz14K4F6V13W8/yY RSZs/8lR7E/tsMyxy0FEmkPiwOoadPJgqTpLo= 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=ghsuChBlaJe3yzYD525KJe6WIL3pojRyov6bEDHlu/rnBxVatQgJ06+Dp3rxJkSQ50 p5O4Uh6ILFbsTx2g9ZH7RPZwqSIeOww8rU+d6JTfZVnyZiFH4Gf5t35/Xr836DFsIShW 3nsfNqp4hFQaVLmoEASwQ3MfMV9Eecl8YqL04= MIME-Version: 1.0 Received: by 10.43.53.133 with SMTP id vq5mr2273597icb.527.1301116331447; Fri, 25 Mar 2011 22:12:11 -0700 (PDT) Received: by 10.42.217.197 with HTTP; Fri, 25 Mar 2011 22:12:11 -0700 (PDT) In-Reply-To: References: Date: Fri, 25 Mar 2011 22:12:11 -0700 Message-ID: Subject: Re: [FlyRotary] Re: Radiator Caps [FlyRotary] Re: On the subject of installations...Coolant Pressure From: David Leonard To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=bcaec51a8a34bf5606049f5bc0ba --bcaec51a8a34bf5606049f5bc0ba Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Unfortunately, I dont konw. My engine monitor ran out of pressure compatable reading, but had some on/off alarms left. So I installed a 4 ps= i pressure switch in the secondary canister. Lets me know if the pressure ever drops away but I don't know the actual value. --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net On Fri, Mar 25, 2011 at 11:51 AM, Bill Bradburry wrote: > Dave, > > > > What does your water pressure run in normal operation? > > > > Bill B > > > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *David Leonard > *Sent:* Friday, March 25, 2011 1:32 PM > > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Radiator Caps [FlyRotary] Re: On the subject o= f > installations...Coolant Pressure > > > > I wonder how much pressure it would really take to blow out the seals on > the pump. My primary cap is 20# and the cap on the seconday tank is 12#. > So my Max pressure is 32# relative to ambient. I only keep a small amoun= t > of coolant in that tank. The air spring takes up all the expansion on mo= st > flights so I usually don't reach full pressure. But a few times I have > overheated the system (Al can attest) and blown out coolant without any > apparent damage to the water pump. > > > > -- > David Leonard > > Turbo Rotary RV-6 N4VY > http://N4VY.RotaryRoster.net > http://RotaryRoster.net > > On Fri, Mar 25, 2011 at 6:10 AM, Ed Anderson > wrote: > > In reading back over my message, I realized that I could mislead some int= o > thinking that the higher cap radiator capacity - but, there is a limit. = At > some point, if the cap did not release pressure, the coolant pressure cou= ld > get high enough to start forcing coolant past seals such as the water pum= p > shaft seal. So don't over do it. > > > > Unless you are going to be flying higher than 18,000MSL, 24 psi is probab= ly > the highest capacity perhaps even 21 psi. You may get away with a 14.7 p= si > cap provided the absolute coolant pressure does not rise above the absolu= te > cap pressure at any given altitude. Cooler ambient air at altitude and l= ess > power could permit a 14.7 psi cap to work, but I personally would hesitat= e > to use less than a 21 psi cap. > > > > Ed > > > > > > > > *From:* Ed Anderson > > *Sent:* Friday, March 25, 2011 8:27 AM > > *To:* Rotary motors in aircraft > > *Subject:* [FlyRotary] Radiator Caps [FlyRotary] Re: On the subject of > installations...Coolant Pressure > > > > One thing to keep in mind about the pressure rating of the radiator cap y= ou > are using. All are rated relative to a standard sea level ambinent > pressure. This means that he air pressure itself is contributing 14.7 ps= i > at sea level. > > > > So at sea level when your differential pressure coolant gauge is reading = 10 > psi - the absolute pressure in your coolant system is then 14.7 + 10 =3D= 24.7 > psi. Now if you are flying at 8000 MSL your ambient pressure is approx 1= /2 > at sea level. So your 14.7 psi CAP now has the lesser capacity of 7.3 + = 10 > =3D 17.3 psi absolute pressure capacity - somewhat less than the 24.7 psi > absolute it had at sea level. > > > > When you increase in altitude this component naturally decreases. So whi= le > a 14.7 psi CAP may work fine at sea level, more than one person found tha= t > at altitude that rating was insufficient and some coolant was lost. > > > > I personally would not fly with less than a 21 psi cap and currently fly > with a 24 psi radiator cap. > > > > There is another factor that occurred to me. Once a hot coolant system > blows the relief valve on the cap, that lowers the pressure inside the > system, superheated (>212F) coolant can quickly flash to steam and furthe= r > cause lost of coolant. So a Higher PSI cap can lessen the chance of that > happening. > > > > FWIW > > > > Ed > > > > *From:* Bill Bradburry > > *Sent:* Thursday, March 24, 2011 5:30 PM > > *To:* Rotary motors in aircraft > > *Subject:* [FlyRotary] Re: On the subject of installations...Coolant > Pressure > > > > Lynn, > > > > You have hit my quandary squarely on the head. Assuming that the pressur= e > was zero at room temp and rose to say 6-7 pounds at 200 degrees, and assu= me > that the flow restriction in the system caused a pressure rise of about 2 > pounds at 2000 rpm and a pressure rise of, say, 6-7 pounds at 6000 rpm. > Under that scenario, you would have a pressure that ran at between 7-9 > pounds at 2000 and rose to 12-14 pounds at 6000. Those pressures would b= e > easily contained with the stock cap of 14 pounds. And the pressure would= be > constantly changing with rpm and possibly temp of the system as you were > under power or not. > > > > I have a 21 pound cap. My system climbs smartly to the top and stays > there. No fluctuation with rpm, no real fluctuation at temp because it h= as > already hit the 21 pounds before the engine is actually hot. (around 190= ) > > > > Something is wrong and I don=92t understand what it is. > > > > Bobby > > > > I am going to insert answers to your questions in your msg below. > > > > Bill B > > > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *Bobby J. Hughes > *Sent:* Thursday, March 24, 2011 1:57 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: On the subject of installations...Coolant > Pressure > > > > Bill, > > > > This is all I can think of at the moment. > > > > Are you running a thermostat or did you plug the hole between the inlets > and outlets of the water pump? > > > > No thermostat. The Renesis has a thermostat tower which is too tall to f= it > under my cowl, so I removed it and fabricated a flat plate with two 1.25 > aluminum tubes for the inlet and outlet of the water pump. That hole you > are referencing exists in the tower, but not in my plate. > > > > If plugged did you drill a small hole in the plug to allow air a place to > escape? I used a #30 drill. > > > > Any air in my system would have to be carried to the highest point, > (radiator cap) then be forced by pressure to the bottom of the swirl tank > where it would be trapped. This seems to be working because I have found > that after I open the system for some reason, the level in the swirl tank > will go down and there is never any air at the top of the radiator. > > > > After an engine run is the radiator the same temperature at the inlet / > outlet / bottom and top? If I have trapped air only part of my radiator g= ets > hot to the touch. Dual pass barrier leaking? > > > > Seems to be. I have mistakenly laid my arm on the top of the radiator > after a run=85usually I manage to get off pretty fast! :>) I can not se= e > into the radiator tank on the barrier side. It is possible it could be > leaking. I suppose if there was a rag in the thing it could be trapped h= ere > also. I have no way to see in there even if the hose was removed. I wou= ld > need some kind of flexible camera or something like that. > > > > Use an extra CHT channel and clamp it to the inlet of your radiator to > measure Delta T. > > > > Good idea. I will have to rig one up. I don=92t have an extra now. > > > > My water pressure does not vary that much in operation. But it does hold = a > little pressure for a few days after shutdown. 1-2 psi. > > > > What is your pressure during operation? What is the pressure cap rating? > Does it vary at all with temp and/or rpm? Mine is maxed out..always! > > > > What size hoses? I=92m running 1in. > > > > The RX-8 uses 1.25 hoses. I stuck with that size as well. > > > > Where are you measuring water pressure? > > > > The hose that comes off the top of the rear iron goes to the top of the > radiator, just below the cap. A tee in this line has the water pressure > sender in it. The radiator cap is just a cap, not a pressure cap. The > outlet in the radiator neck goes to the bottom of the swirl tank. > > > > Is your pressure cap on the bleed / swirl tank? > > > > Yes. > > > > Any pictures of the plumbing? > > > > Not of the current setup. > > > > Bobby > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *Bill Bradburry > *Sent:* Thursday, March 24, 2011 10:23 AM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] On the subject of installations...Coolant Pressure > > > > I need some help with figuring out my cooling problems. > > > > Just so it doesn=92t get lost in the following BS, I need to state that I > think the problem is related to the coolant pressure. It seems to me to = be > way too high. I am beginning to think that the coolant is somehow partia= lly > blocked. > > > > Now the rest of the story=85. > > > > After I did the flight described in the attached email, I installed an > opening in the bottom of the cowl that would work something like a cowl f= lap > that is permanently open. The new opening is 9 inches by 5 inches or 54 = sq > in.. There is a flare in front of the opening that is at an angle of 45 > degrees and extends down into the airstream about 4 inches. (it is 6 inc= hes > long.) This opening is in addition to two 6 X 6 openings, one of which h= as > a 3 inch diameter exhaust pipe in it. > > > > This helped a little, but nothing like I expected it would. The pressure > inside the radiator inlet dropped from 10 inches of water to 8 inches of > water. (by the way, Steve was right about it being inches of water and n= ot > inches of Hg.) > > The pressure after the radiator and inside the cowl dropped to 8 inches a= s > well. The temperature of the water dropped to 208 and the oil a couple o= f > degrees. Neither of these had the result that I expected. > > > > My water pressure cap is rated at 21 lbs. I have not calibrated the send= er > that came with my EM-2 and it shows 3 lbs when the engine is cold. I ass= ume > that this is zero. When in flight the pressure climbs to 24 lbs and stay= s > there. I assume that at this point, the cap is at 21 lbs and is bleeding > off air. There is about a pint to a quart of air above the coolant in th= e > bleed tank. > > > > This morning I ran the engine on the ground for about 10-15 minutes at an > rpm of 3000 to 3200. The OAT was 75 degrees. > > > > I read the temps and pressures every minute or two during the run. I hop= e > this doesn=92t get jumbled during transmission. > > > > Oil temp =96 80 103 130 > 139 144 155 162 165 > > Air temp after cooler - 97 > 109 122 129 133 > 134 > > > > Water temp - 86 126 161 > 173 178 190 198 199 > > Air temp after rad - 109 > 133 157 169 179 > 183 > > > > Water pressure - 2 11 17 > 20 21 24 > > > > I noticed that the water pressure could be brought from 2 lbs to 9 lbs by > changing the rpm while the engine was still relatively cool > > > > What should I expect for water pressure at lower temps and how could I go > about making a determination that the water passages are clear? > > > > I am beginning to think that a rag has been left either in the engine or > the radiator. I have never torn the engine down and I sent the radiator = out > to have a leak repair a couple of years ago. It is a double pass radiato= r. > I can look into the end that has both sides connected thru the radiator c= ap > neck, but not into the inlet and outlet end. > > > > Suggestions??? > > > > Thanks, > > > > Bill B > > > ------------------------------ > > *From:* Bill Bradburry [mailto:bbradburry@bellsouth.net] > *Sent:* Sunday, March 20, 2011 5:29 PM > *To:* 'Rotary motors in aircraft' > *Subject:* On the subject of installations... > > > > My water temp has been running between 199 and 217, depending on the OAT. > The oil is pretty steady at around 175. Today I finally got to fly with > pressure probes inside the cowling. I was all set to try and enlarge the > inlet to the radiator to solve the problem. It turns out that =93in=94 i= s not > the problem, it is =93out=94 that is the problem! > > > > I have 10 inches of Hg pressure in the radiator inlet and 10 inches of Hg > on the outlet side as well as the same pressure everywhere I measured ins= ide > the cowl. I need to open up the cowl some so more air can get out. I ha= d > considered a cowl flap but that would not work in this instance because t= he > problem is at cruise. I need a permanent opening. I am considering louv= ers > and I am looking for a source. I know some of you are using them. Where > did you get them and how are they installed so that they look ok? > > > > I am also considering some kind of flare around the exit area to create a > low pressure area to help suck air out. Do any of you have those and do > they seem to work? > > > > While I look into this, I also need to do something about my muffler=85Th= ank > you, Bobby! > > > > I wonder about that spiral muffler some of you are trying?? > > > > Bill B 9 hours and counting=85 > > > > By the way, I was considering putting a 1 or 2 inch wide piece of cardboa= rd > across the bottom of the oil cooler to partially block it in the hopes th= at > more air would then flow through the radiator. Sort of like truckers do > with the radiator in cold weather. What opinions do you have about that > idea? I realize it would make more sense if the oil was really cool, but= I > think the oil might not get much hotter if an inch or so was blocked. Wh= at > do you think??? > > > > --bcaec51a8a34bf5606049f5bc0ba Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Unfortunately, I dont konw.=A0=A0 My engine monitor ran out of pressur= e compatable reading, but had some on/off alarms left.=A0 So I installed a = 4 psi pressure switch in the secondary canister.=A0 Lets me know if the pre= ssure ever drops away but I don't know the actual value.

--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net


On Fri, Mar 25, 2011 at 11:51 AM, Bill Bradburry= <bbradbur= ry@bellsouth.net> wrote:

Dave,

=A0

What does your = water pressure run in normal operation?

=A0

Bill B

=A0

From:= Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of David Leonard Sent: Friday, March 25, 201= 1 1:32 PM=20


To: R= otary motors in aircraft
Subj= ect: [FlyRotary] Re: Radiator Caps [FlyRotary] Re: On the subjec= t of installations...Coolant Pressure=20

=A0

I wonder how much pressure it would really take to bl= ow out the seals on the pump.=A0 My primary cap is 20# and the cap on the s= econday tank is 12#.=A0 So my Max pressure is 32# relative to ambient.=A0= =A0I only keep a small amount of coolant in that tank.=A0 The air spring ta= kes up all the expansion on most flights so I usually don't reach full = pressure. But a few times I have overheated=A0the system (Al can attest)=A0= and blown out coolant without any apparent damage to the water pump.=

=A0

--
David Leonard
Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.= net

On Fri, Mar 25, 2011 at 6:10 AM, Ed Anderson <eanderson@caroli= na.rr.com> wrote:

In reading back over my message, I realized= that I could mislead some into thinking that the higher cap radiator capac= ity - but, there is a limit.=A0 At some point, if the cap did not release p= ressure, the coolant pressure could get high enough to start forcing coolan= t past seals such as the water pump shaft seal.=A0 So don't over do it.= =A0

=A0

Unless you are going to be flying higher th= an 18,000MSL, 24 psi is probably the highest capacity perhaps even 21 psi.= =A0 You may get away with a 14.7 psi cap provided the absolute coolant pres= sure does not rise above the absolute cap pressure at any given altitude.= =A0 Cooler ambient air at altitude and less power could permit a 14.7 psi c= ap to work, but I personally would hesitate to use less than a 21 psi cap.<= /span>

=A0

Ed

=A0

=A0

=A0

From: Ed= Anderson

Sent: Friday, March 25, 2011 8:2= 7 AM

Subject: [FlyRotary] Radiator Ca= ps [FlyRotary] Re: On the subject of installations...Coolant Pressure

=A0

One thing to keep in mind about the pressur= e rating of the radiator cap you are using.=A0 All are rated relative to a = standard sea level ambinent pressure.=A0 This means that he air pressure it= self is contributing 14.7 psi at sea level.=A0

=A0

So at sea level when your differential pres= sure coolant gauge is reading 10 psi - the absolute pressure in your coolan= t system is then =A014.7 + 10 =3D 24.7 psi.=A0 Now if you are flying at 800= 0 MSL your ambient pressure is approx 1/2 at sea level.=A0 So your 14.7 psi= CAP now has the lesser capacity of 7.3 + 10 =3D 17.3 psi absolute pressure= capacity - somewhat less than the 24.7 psi absolute it had at sea level.

=A0

When you increase in altitude this componen= t naturally decreases.=A0 So while a 14.7 psi CAP may work fine at sea leve= l, more than one person found that at=A0altitude=A0 that rating was=A0 insu= fficient and some coolant was lost.

=A0

I personally would not fly with less than a= 21 psi cap and currently fly with a 24 psi radiator cap.

=

=A0

There is another factor that occurred to me= .=A0 Once a=A0hot coolant system blows the relief valve on the cap, that lo= wers the pressure inside the system, superheated (>212F) coolant can qui= ckly flash to steam and further cause lost of coolant.=A0 So a Higher PSI c= ap can lessen the chance of that happening.=A0

=A0

FWIW

=A0

Ed

=A0

Sent: Thursday, March 24, 2011 5= :30 PM

Subject: [FlyRotary] Re: On the = subject of installations...Coolant Pressure

=A0

Lynn,

=A0

You have hit my= quandary squarely on the head.=A0 Assuming that the pressure was zero at r= oom temp and rose to say 6-7 pounds at 200 degrees, and assume that the flo= w restriction in the system caused a pressure rise of about 2 pounds at 200= 0 rpm and a pressure rise of, say, 6-7 pounds at 6000 rpm.=A0 Under that sc= enario, you would have a pressure that ran at between 7-9 pounds at 2000 an= d rose to 12-14 pounds at 6000.=A0 Those pressures would be easily containe= d with the stock cap of 14 pounds.=A0 And the pressure would be constantly = changing with rpm and possibly temp of the system as you were under power o= r not.

=A0

I have a 21 pou= nd cap.=A0 My system climbs smartly to the top and stays there.=A0 No fluct= uation with rpm, no real fluctuation at temp because it has already hit the= 21 pounds before the engine is actually hot.=A0 (around 190)=

=A0

Something is wr= ong and I don=92t understand what it is.

=A0

Bobby

=A0

I am going to i= nsert answers to your questions in your msg below.

=A0

Bill B

=A0

From:= Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes<= br> Sent: Thursday, March 24, 2= 011 1:57 PM
To: Rotary m= otors in aircraft
Subject: [FlyRotary] Re: On the subject of installations...Coolant Pressure

=A0

Bill,

=A0

This is all I c= an think of at the moment.

=A0

Are you running= a thermostat or did you plug the hole between the inlets and outlets of th= e water pump?

=A0

No thermostat.=A0= The Renesis has a thermostat tower which is too tall to fit under my cowl,= so I removed it and fabricated a flat plate with two 1.25 aluminum tubes f= or the inlet and outlet of the water pump.=A0 That hole you are referencing= exists in the tower, but not in my plate.

=A0

If plugged did = you drill a small hole in the plug to allow air a place to escape? I used a= #30 drill.

=A0

Any air in my sys= tem would have to be carried to the highest point, (radiator cap) then be f= orced by pressure to the bottom of the swirl tank where it would be trapped= .=A0 This seems to be working because I have found that after I open the sy= stem for some reason, the level in the swirl tank will go down and there is= never any air at the top of the radiator.

=A0

After an engine= run is the radiator the same temperature at the inlet / outlet / bottom an= d top? If I have trapped air only part of my radiator gets hot to the touch= . Dual pass barrier leaking?

=A0

Seems to be.=A0 I= have mistakenly laid my arm on the top of the radiator after a run=85usual= ly I manage to get off pretty fast!=A0 :>)=A0 I can not see into the rad= iator tank on the barrier side.=A0 It is possible it could be leaking.=A0 I= suppose if there was a rag in the thing it could be trapped here also.=A0 = I have no way to see in there even if the hose was removed.=A0 I would need= some kind of flexible camera or something like that.

=A0

Use an extra CH= T channel and clamp it to the inlet of your radiator to measure Delta T.

=A0

Good idea.=A0 I w= ill have to rig one up.=A0 I don=92t have an extra now.

=A0

My water pressu= re does not vary that much in operation. But it does hold a little pressure= for a few days after shutdown. =A01-2 psi.

=A0

What is your pres= sure during operation?=A0 What is the pressure cap rating?=A0 Does it vary = at all with temp and/or rpm?=A0 Mine is maxed out..always!

=A0

What size hoses= ? I=92m running 1in.

=A0

The RX-8 uses 1.2= 5 hoses.=A0 I stuck with that size as well.

=A0

Where are you m= easuring water pressure? =A0

=A0

The hose that com= es off the top of the rear iron goes to the top of the radiator, just below= the cap. A tee in this line has the water pressure sender in it.=A0 The ra= diator cap is just a cap, not a pressure cap.=A0 The outlet in the radiator= neck goes to the bottom of the swirl tank.

=A0

Is your pressur= e cap on the bleed / swirl tank?

=A0

Yes.

=A0

Any pictures of= the plumbing?

=A0

Not of the curren= t setup.

=A0

Bobby

From:= Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry Sent: Thursday, March 24, 2= 011 10:23 AM
To: Rotary = motors in aircraft
Subject:<= /b> [FlyRotary] On the subject of installations...Coolant Pressure

=A0

I need some hel= p with figuring out my cooling problems.

=A0

Just so it does= n=92t get lost in the following BS, I need to state that I think the proble= m is related to the coolant pressure.=A0 It seems to me to be way too high.= =A0 I am beginning to think that the coolant is somehow partially blocked.<= /span>

=A0

Now the rest of= the story=85.

=A0

After I did the= flight described in the attached email, I installed an opening in the bott= om of the cowl that would work something like a cowl flap that is permanent= ly open.=A0 The new opening is 9 inches by 5 inches or 54 sq in..=A0 There = is a flare in front of the opening that is at an angle of 45 degrees and ex= tends down into the airstream about 4 inches.=A0 (it is 6 inches long.)=A0 = This opening is in addition to two 6 X 6 openings, one of which has a 3 inc= h diameter exhaust pipe in it.

=A0

This helped a l= ittle, but nothing like I expected it would.=A0 The pressure inside the rad= iator inlet dropped from 10 inches of water to 8 inches of water.=A0 (by th= e way, Steve was right about it being inches of water and not inches of Hg.= )

The pressure af= ter the radiator and inside the cowl dropped to 8 inches as well.=A0 The te= mperature of the water dropped to 208 and the oil a couple of degrees.=A0 N= either of these had the result that I expected.

=A0

My water pressu= re cap is rated at 21 lbs.=A0 I have not calibrated the sender that came wi= th my EM-2 and it shows 3 lbs when the engine is cold.=A0 I assume that thi= s is zero.=A0 When in flight the pressure climbs to 24 lbs and stays there.= =A0 I assume that at this point, the cap is at 21 lbs and is bleeding off a= ir.=A0 There is about a pint to a quart of air above the coolant in the ble= ed tank.

=A0

This morning I = ran the engine on the ground for about 10-15 minutes at an rpm of 3000 to 3= 200.=A0 The OAT was 75 degrees.

=A0

I read the temp= s and pressures every minute or two during the run.=A0 I hope this doesn=92= t get jumbled during transmission.

=A0

Oil temp =96 = =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A080 =A0=A0=A0= =A0=A0103=A0=A0=A0=A0=A0 130=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 139=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 144=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 155=A0= =A0=A0=A0=A0=A0=A0=A0=A0 162=A0=A0=A0=A0=A0=A0=A0=A0 165

Air temp after = cooler - =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A097=A0=A0=A0=A0=A0=A0 109= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0 122=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 129=A0=A0=A0=A0=A0= =A0=A0=A0=A0 133=A0=A0=A0=A0=A0=A0=A0=A0 134

=A0

Water temp -=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 86=A0=A0=A0=A0=A0=A0 126= =A0=A0=A0=A0=A0 161=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 173=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0 178=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 190=A0=A0=A0=A0= =A0=A0=A0=A0=A0 198=A0=A0=A0=A0=A0=A0=A0=A0=A0 199

Air temp after = rad -=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 109=A0=A0=A0= =A0=A0 133=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 157=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 169=A0=A0= =A0=A0=A0=A0=A0=A0=A0 179=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 183

=A0

Water pressure = -=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 2=A0=A0=A0=A0=A0=A0=A0=A0=A0 11=A0=A0= =A0=A0=A0=A0=A0 17=A0=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A020=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 21=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 24=A0=A0=A0=A0=A0

=A0

I noticed that = the water pressure could be brought from 2 lbs to 9 lbs by changing the rpm= while the engine was still relatively cool

=A0

What should I e= xpect for water pressure at lower temps and how could I go about making a d= etermination that the water passages are clear?

=A0

I am beginning = to think that a rag has been left either in the engine or the radiator.=A0 = I have never torn the engine down and I sent the radiator out to have a lea= k repair a couple of years ago.=A0 It is a double pass radiator.=A0 I can l= ook into the end that has both sides connected thru the radiator cap neck, = but not into the inlet and outlet end.

=A0

Suggestions???<= /span>

=A0

Thanks,<= /font>

=A0

Bill B

=A0

From:= Bill Bradburry [mailto:bbradburry@bellsouth.net]
Sent: Sunday, March 20, 201= 1 5:29 PM
To: 'Rotar= y motors in aircraft'
Subject:<= /span> On the subject of installations...

=A0

My water temp h= as been running between 199 and 217, depending on the OAT.=A0 The oil is pr= etty steady at around 175.=A0 Today I finally got to fly with pressure prob= es inside the cowling.=A0 I was all set to try and enlarge the inlet to the= radiator to solve the problem.=A0 It turns out that =93in=94 is not the pr= oblem, it is =93out=94 that is the problem!

=A0

I have 10 inche= s of Hg pressure in the radiator inlet and 10 inches of Hg on the outlet si= de as well as the same pressure everywhere I measured inside the cowl.=A0 I= need to open up the cowl some so more air can get out.=A0 I had considered= a cowl flap but that would not work in this instance because the problem i= s at cruise.=A0 I need a permanent opening.=A0 I am considering louvers and= I am looking for a source.=A0 I know some of you are using them.=A0 Where = did you get them and how are they installed so that they look ok?

=A0

I am also consi= dering some kind of flare around the exit area to create a low pressure are= a to help suck air out.=A0 Do any of you have those and do they seem to wor= k?

=A0

While I look in= to this, I also need to do something about my muffler=85Thank you, Bobby!

=A0

I wonder about = that spiral muffler some of you are trying??

=A0

Bill B=A0 9 hou= rs and counting=85

=A0

By the way, I w= as considering putting a 1 or 2 inch wide piece of cardboard across the bot= tom of the oil cooler to partially block it in the hopes that more air woul= d then flow through the radiator.=A0 Sort of like truckers do with the radi= ator in cold weather.=A0 What opinions do you have about that idea?=A0 I re= alize it would make more sense if the oil was really cool, but I think the = oil might not get much hotter if an inch or so was blocked.=A0 What do you = think???



<= /div>


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