X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 12 Mar 2009 10:30:48 -0400 Message-ID: X-Original-Return-Path: Received: from web111410.mail.gq1.yahoo.com ([67.195.15.186] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with SMTP id 3544816 for lml@lancaironline.net; Thu, 12 Mar 2009 01:08:03 -0400 Received-SPF: none receiver=logan.com; client-ip=67.195.15.186; envelope-from=randylsnarr@yahoo.com Received: (qmail 70190 invoked by uid 60001); 12 Mar 2009 05:07:28 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:MIME-Version:Content-Type; b=498GAc+rG37si/tcStLHHrbtPAw3/unGOQIHe1ADyEztlXV/EIgY1FZRqgR/LJx8nvHAEGCkiwRzj4HFZU0ovi6b/w/GfPBMfq4oBRkF0cA7UFEqNyhkw00ICBMubWm2I9Yg2jXy/UUap/SfnYl9bNmjH46k8PaWrU1iQrkWlE0=; X-Original-Message-ID: <431146.69016.qm@web111410.mail.gq1.yahoo.com> X-YMail-OSG: pDfsziwVM1kTQ0FD8ifaVE2ERxRtGoPtC2qQOEPkG1eercp_roxMX_BWPL0JZIPWbrgh6M0m3pGOph3uumL.zp89nupakh.cV5dDerC1TQqoS7y1iY7ctdwQNTatayBDCdr1yhqDLVSKz3kCCtHBAYTfGftLp0lXVg3om2fBimMGEJXGPZvDhFa7lTCk_rgr71dKcYt.k7dvu83Cx_cko.5Ik8DTANbD7.QT_Yf00Kxsqd2UmlbQUiV2DFabgP3ucSa2JzX3aUXeaHnkiy6J_ngCOqWpPO0guQ02Sl1cVLEWB8Twr9Y- Received: from [76.8.220.18] by web111410.mail.gq1.yahoo.com via HTTP; Wed, 11 Mar 2009 22:07:28 PDT X-Mailer: YahooMailClassic/5.1.19 YahooMailWebService/0.7.289.1 X-Original-Date: Wed, 11 Mar 2009 22:07:28 -0700 (PDT) From: randy snarr Subject: Re: [LML] Re: oil cooling/ head temps X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-365401065-1236834448=:69016" --0-365401065-1236834448=:69016 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Gary, I have changed how my exhaust is supported to stop the cracking. Originally= I had no supports. I only had the pipes connected to each other at the tai= ls.=A0 I have had one crack where the #4 tube is welded to the wrap around = pipe early in my flying about 75 hours if memory serves. I did what the RV = guys do and made a support that connects the pipe to the engine just behind= the sump using 2 supports. As for inspection, I just put the wrap on last = year. I removed it when I did some major work on the engine and there were = no cracks. This time, I was so impressed with how well the material perform= ed when I did my experiment, I decided to add several layres on the entire = exhaust. I will just unwrap it once each year at annual. If it goes 2 or 3 = years with no cracking I may go every other year on the inspection. I would= also not make the wrap super tight. When it is a little loose, it holds th= e heat in better and it has a natural dampening affect on the pipes. Try to make a pitch fork ring with a sock over it.... What are your head temps running at?=20 I think there is a flaw in the lower cowl design of the 235/320/360 series = Lancairs. If you look on any production airplane. The openings on the botto= m of the cowls all have an angled piece or lip angled away from the opening= to create a low pressure area. I think that ours should have that as well.= I also think we are getting airflow into the slot in the bottom of the cow= l where the nose gear travels. My friend had major head cooling issue on his Zenith 801 and tried everythi= ng to get them to cool down to no avail.=A0 When he added a lip on the bott= tom opening of his cowl, shazam! head temps waaay down. I have been trying to think of a way to test that on my airplane without bu= ggering up my paint as that may be the answer to my oil cooling issue. I did a little better job of sealing around the engine baffeling with RTV t= o get the best affect from the plennum cooler. I also did the exhaust wrap,= opened up the exits under each cylinder. I also radiused those exits. All = of that changed my head temps from running in the upper 300's and 25 degree= s apart to 360 F average with all the heads running within 5 or 10 Degrees = of each other. Not sure what did what but I like where I am on that front. Randy Snarr --- On Tue, 3/10/09, Gary Edwards wrote: From: Gary Edwards Subject: [LML] Re: oil cooling/ head temps To: lml@lancaironline.net Date: Tuesday, March 10, 2009, 8:37 PM =0A=0A =0A=0AGood information Randy.=A0=A0=0A=A0=0AOn this bird, the cylind= er with the highest CHT=A0(#3) has the least =0Aamount of exhaust piping in= its vicinity.=A0 As you know the exhaust pipes =0Aare routed around the le= ft side.=A0 Those side cylinders (#2, #4) have CHT's =0Alower than=A0#3.=A0= =A0Also, the headers are heat coated on =0Athe=A0inside.=A0 The engine has= been sealed up with RTV=A0at every =0Aopening.=A0 That was the first thing= I did 10 years ago.=A0 The bottom =0Awrap-under baffling on #3 was=A0opene= d up then also.=A0 I have modified =0Athe rear baffling on #3 head so as to= create an air space where there was none =0Abefore (the rear of #3 has no = cooling fins so the baffling is typically tight =0Aagainst the head).=A0 Re= moving the=A04" exit scat tubing from the oil =0Acoolers did nothing to low= er the CHT's or RAISE the oil temps.=A0 Bottom cowl =0Arear exit area (sq. = in.) was calculated and is equal to or more than standard =0A320 and RV cow= ls.=A0=A0=0A=A0=0AHow do you do visual condition inspections on the headers= with the pipe =0Awrap on them?=A0 Of all the=A0repairs I have had to do in= the engine =0Acompartment, the most have been to=A0the headers.=A0 Multipl= e cracks to =0Aweld - stainless headers.=0A=A0=0AGary=A0=A0=A0=A0=A0=0A=0A = ----- Original Message ----- =0A From: randy =0A snarr =0A To: lml@lanc= aironline.net =0A Sent: Monday, March 09, 2009 10:41 =0A AM=0A Subject: = [LML] Re: oil cooling/ head =0A temps=0A =20 =0A =0A =0A =0A Gary, One side note on the head temps. I made m= y plennum =0A similar to yours. My head temps run within 6 deg of each other =0A usually 310-360 F d= epending on power and temps. One thing that I =0A did was to shine a light up through the bottom = of engine with the hangar =0A lights out and found and sealed EVERY = gap in the baffeling except where =0A cooling air needs to go with h= igh temp RTV. I also opened up the gap =0A on the bottom of each cyl to 2.6" times= the dept of the cooling fins as =0A I read somewhere NASA had done = some testing and determined that was the =0A optimum opening. I also= radiused the baffeling exits inder the cylingers =0A rather than 90= deg bends on the exits. I understand that helps flow as =0A well. I have also come to the conclusion that there is airflow =0A coming = into the cowl through the nose gear slot and bottom exit cowl =0A ar= ea. I see this when I get an oil leak. the oil runs down and then =0A = blows forward. Weird. Ayway, you may need a small 45 deg lip on the =0A = bottom of your cowl exit like I probably do. One last thing of =0A note, in my pictures you will see the exhaust = wrap, that did make a =0A difference on head temps and it also evene= d them up. My exhaust wraps =0A around the engine like yours does an= d runs close under the cyinders. I =0A wrapped those areas with 4 la= yers of exhaust wrap and 2 or 3 layres =0A everywhere else and have = had good results lowering engine compartment =0A temps-unmeasured bu= t it appears to be so. I tested the heat wrap on my =0A heat gun. Wi= th 4 loose layres I could hold my hand on a heat gun nozzle =0A on t= he high heat setting. That sold me on that =0A stuff. FWIW... Randy Snarr N694RS --- On Sat, =0A 3/7/09, Gary Edwards wrote: =0A =20 From: =0A Gary Edwards Subject: [LML] Re: oil =0A cooling To: lml@lancaironline.net Date: Saturday, March 7, 2009, =0A 6:33 PM =0A =0A =0A=0A =0A It seems that most t= emp issues are with oil.=A0 Mine are not =0A with oil, but with CH= T's.=0A =A0=0A As you know (you have seen pictures), I ha= ve 2 smaller (6" round) =0A oil coolers, one on each side (mounted= to the engine mount) with naca =0A ducts and short 4" to 6" long = straight 2" inch scat duct to =0A them.=A0 The scat duct is connec= ted=A0via glass enlargers.=A0 =0A On the outlet side, there are gl= ass reducers down to 4" scat duct, =0A with the duct routed down t= o near the nose gear front cover on the =0A firewall.=A0 It as clo= se to the=A0lower cowl outlet area that I =0A could get.=0A = =A0=0A The oil temps. are too low, especially in winter.=A0 It = is =0A difficult to get the temp to 180.=A0 In summer, the oil tem= p is =0A about 190 to 200 climb and cruise.=A0 I tried (for winter= ) closing =0A off one cooler with duct tape over the cowl inlet to= raise the temp =0A and it didn't make any difference.=A0 Tried it= on both sides.=A0 =0A I also removed the 4" outlet duct (reducers= left on), to let the =0A outlet flow directly into the rear cowl = area, with no change =0A noticed.=A0 In only one case, have I had = a high oil temp; in Bend, =0A Or.,=A0giving a friend a ride after = a previous flight.=A0 =0A Outside temp=A0in the '70's.=A0 Never ha= s happened again.=0A =A0=0A Now, if I could just get my C= HT's down.=A0 I have to step =0A climb with that issue when=A0at g= ross weight.=0A =A0=0A Gary Edwards=0A LNC2 =0A2= 35/320 =0A=0A=0A --0-365401065-1236834448=:69016 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Gary,
I have changed how my exhaust is sup= ported to stop the cracking. Originally I had no supports. I only had the p= ipes connected to each other at the tails.  I have had one crack where= the #4 tube is welded to the wrap around pipe early in my flying about 75 = hours if memory serves. I did what the RV guys do and made a support that c= onnects the pipe to the engine just behind the sump using 2 supports. As fo= r inspection, I just put the wrap on last year. I removed it when I did som= e major work on the engine and there were no cracks. This time, I was so im= pressed with how well the material performed when I did my experiment, I de= cided to add several layres on the entire exhaust. I will just unwrap it on= ce each year at annual. If it goes 2 or 3 years with no cracking I may go e= very other year on the inspection. I would also not make the wrap super tig= ht. When it is a little loose, it holds the heat in better and it has a natura= l dampening affect on the pipes. Try to make a pitch fork ring with a sock = over it....

What are your head temps running at?

I think the= re is a flaw in the lower cowl design of the 235/320/360 series Lancairs. I= f you look on any production airplane. The openings on the bottom of the co= wls all have an angled piece or lip angled away from the opening to create = a low pressure area. I think that ours should have that as well. I also thi= nk we are getting airflow into the slot in the bottom of the cowl where the= nose gear travels.
My friend had major head cooling issue on his Zenith= 801 and tried everything to get them to cool down to no avail.  When = he added a lip on the botttom opening of his cowl, shazam! head temps waaay= down.
I have been trying to think of a way to test that on my airplane = without buggering up my paint as that may be the answer to my oil cooling issue.
I did a little better job of sealing around the engine b= affeling with RTV to get the best affect from the plennum cooler. I also di= d the exhaust wrap, opened up the exits under each cylinder. I also radiuse= d those exits. All of that changed my head temps from running in the upper = 300's and 25 degrees apart to 360 F average with all the heads running with= in 5 or 10 Degrees of each other. Not sure what did what but I like where I= am on that front.

Randy Snarr


--- On Tue, 3/10/09, Ga= ry Edwards <gary21sn@hotmail.com> wrote:

From: Gary Edwards <gary21sn@hotmail.com>
Subject: = [LML] Re: oil cooling/ head temps
To: lml@lancaironline.net
Date: Tue= sday, March 10, 2009, 8:37 PM

=0A=0A =0A=0A
Good information Randy.  
=0A
 
=0A=
On this bird, the cylinder with the highest CHT (#3) has the leas= t =0Aamount of exhaust piping in its vicinity.  As you know the exhaus= t pipes =0Aare routed around the left side.  Those side cylinders (#2,= #4) have CHT's =0Alower than #3.   Also, the headers are he= at coated on =0Athe inside.  The engine has been sealed up with R= TV at every =0Aopening.  That was the first thing I did 10 years = ago.  The bottom =0Awrap-under baffling on #3 was opened up then = also.  I have modified =0Athe rear baffling on #3 head so as to create= an air space where there was none =0Abefore (the rear of #3 has no cooling= fins so the baffling is typically tight =0Aagainst the head).  Removi= ng the 4" exit scat tubing from the oil =0Acoolers did nothing to lowe= r the CHT's or RAISE the oil temps.  Bottom cowl =0Arear exit area (sq= . in.) was calculated and is equal to or more than standard =0A320 and RV c= owls.  
=0A
 
=0A
How do you do visual con= dition inspections on the headers with the pipe =0Awrap on them?  Of a= ll the repairs I have had to do in the engine =0Acompartment, the most= have been to the headers.  Multiple cracks to =0Aweld - stainles= s headers.
=0A
 
=0A
Gary    &nb= sp;
=0A
=0A=
----- Original Mess= age -----
=0A =0A =0A
Sent: Monday, March 09, 2009 10:41 =0A AM
=0A
Subject: [LML] Re: oi= l cooling/ head =0A temps
=0A

=0A =0A =0A =0A Gary, One side note on the head temps. I made my plennum = =0A similar to yours.
My head temps run within 6 deg of each othe= r =0A usually 310-360 F depending on power and temps.

One thi= ng that I =0A did was to shine a light up through the bottom of engi= ne with the hangar =0A lights out and found and sealed EVERY gap in = the baffeling except where =0A cooling air needs to go with high tem= p RTV.
I also opened up the gap =0A on the bottom of each cyl to = 2.6" times the dept of the cooling fins as =0A I read somewhere NASA= had done some testing and determined that was the =0A optimum openi= ng. I also radiused the baffeling exits inder the cylingers =0A rath= er than 90 deg bends on the exits. I understand that helps flow as =0A = well.

I have also come to the conclusion that there is airflow = =0A coming into the cowl through the nose gear slot and bottom exit = cowl =0A area. I see this when I get an oil leak. the oil runs down = and then =0A blows forward. Weird. Ayway, you may need a small 45 de= g lip on the =0A bottom of your cowl exit like I probably do.
One last thing of =0A note, in my pictures you will see the exhaust= wrap, that did make a =0A difference on head temps and it also even= ed them up. My exhaust wraps =0A around the engine like yours does a= nd runs close under the cyinders. I =0A wrapped those areas with 4 l= ayers of exhaust wrap and 2 or 3 layres =0A everywhere else and have= had good results lowering engine compartment =0A temps-unmeasured b= ut it appears to be so. I tested the heat wrap on my =0A heat gun. W= ith 4 loose layres I could hold my hand on a heat gun nozzle =0A on = the high heat setting. That sold me on that =0A stuff.

FWIW..= .
Randy Snarr
N694RS

--- On Sat, =0A 3/7/09, Gary Ed= wards <gary21sn@hotmail.com> wrote:
=0A
From: =0A Gary Edwards <gary21sn@hotmail.c= om>
Subject: [LML] Re: oil =0A cooling
To: lml@lancaironl= ine.net
Date: Saturday, March 7, 2009, =0A 6:33 PM

=0A =
=0A =0A=0A =
=0A
It seems that most temp issues are with oil. = ; Mine are not =0A with oil, but with CHT's.
=0A  
=0A
As you know (you have seen pictures), I hav= e 2 smaller (6" round) =0A oil coolers, one on each side (mounted = to the engine mount) with naca =0A ducts and short 4" to 6" long s= traight 2" inch scat duct to =0A them.  The scat duct is conn= ected via glass enlargers.  =0A On the outlet side, ther= e are glass reducers down to 4" scat duct, =0A with the duct route= d down to near the nose gear front cover on the =0A firewall. = ; It as close to the lower cowl outlet area that I =0A could = get.
=0A
 
=0A
The oil temps. ar= e too low, especially in winter.  It is =0A difficult to get = the temp to 180.  In summer, the oil temp is =0A about 190 to= 200 climb and cruise.  I tried (for winter) closing =0A off = one cooler with duct tape over the cowl inlet to raise the temp =0A = and it didn't make any difference.  Tried it on both sides.  = =0A I also removed the 4" outlet duct (reducers left on), to let t= he =0A outlet flow directly into the rear cowl area, with no chang= e =0A noticed.  In only one case, have I had a high oil temp;= in Bend, =0A Or., giving a friend a ride after a previous fl= ight.  =0A Outside temp in the '70's.  Never has ha= ppened again.
=0A
 
=0A
Now, if = I could just get my CHT's down.  I have to step =0A climb wit= h that issue when at gross weight.
=0A
 
= =0A
Gary Edwards
=0A
LNC2 =0A235/320
=

<= /div>

=0A=0A=0A=0A --0-365401065-1236834448=:69016--