REFLECTOR:Oil temps and heating
Dave Nelson
reflector@tvbf.org
Thu, 23 Oct 2003 21:23:47 -0500
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I'm fairly new to the reflector, so I apologise if this subject has =
been covered before. I guess I'd be a bit surprised if it hadn't...
I've just passed 600 hours on my STD-RG, which I built. I live in =
Minnesota, and winters are long up here, so I always search for good =
projects to upgrade my aircraft over those long winter months. Last =
winter I decided to clean up the lower cowl in order to improve speed & =
performance.... you see, my hangar mate is a beautiful Cozy 3 place. =
With his 150 horses, he's close (way too close) to keeping up with me in =
my IO-360 powered, 200 HP velocity RG. It's always a race when we go =
flying...
My plan was to do drag reduction to the lower cowl by reworking the =
armpit scoops I use for cooling air and eliminating the induction air =
scoop. My airplane's been flying for quite awhile now, so I'm sure you =
guys and the factory have come up with 50 better solutions than what use =
to have... which was the factory standard scoops mounted on the cowl, =
and separate "inner" scoops that were mounted to the sides of the =
fuselage and ducted cooling air to the plenum. I orignally made the =
inner/outer scoop combination to make it easy to remove the lower cowl =
without having to muck with anything. It worked well, but there was =
quite a gap required between the inner fuselage mounted scoops and the =
cowling. =20
I figured I could reduce the total scoop size by about 25% and improve =
cooling in the process by getting rid of the gap. Cooling would be =
improved given that high pressure air was leaking into the lower engine =
area through the gap... by tightening up the outer scoop I would =
actually increase the differential pressure between the plenum and the =
lower engine area, and also reduce overall drag. At least that was the =
theory. So, I reworked the whole system - I made smaller armpit scoops =
that are mounted to the fuselage, and reformed the cowl to fit tight =
against the new scoops. I faired the new scoops into the cowl so that =
the airflow stays attached as long as possible. Additionally, I made a =
small plenum that provides both engine induction air and cooling air =
from the right hand armpit scoop, thereby eliminating the drag from the =
separate induction air scoop. =20
Results from all this work are very mixed... my speed didn't increase at =
all despite the drag reductions. You may laugh at my stupidity on this, =
but I neglected the fact that by not separating the air in the new small =
cooling/induction air plenum, I lost the ram air effect on the induction =
air side. I lost about 1.5 inches of maximum manifold pressure because =
I didn't separate the induction air from the cooling air on the right =
scoop. Alas, a project for this winter. The real problem, though, has =
been that with this new setup, my oil temps have become very difficult =
to manage. =20
>From a cooling perspective, I've got the standard nose mounted oil =
cooler and cabin heat system. Before the modification, my oil temps =
rarely got up to 100 C (212 F), and my CHTs were all around 350 F +/- 25 =
degrees. Now, in a climb I can easily heat the oil to redline (242 F) if =
I'm not careful. After much thought and work, it appears that the =
leakage air that was slipping between the inner and outer armpit scoops =
and pressurizing the lower cowl also had a cooling effect on the =
accessory case, oil sump, and the oil temperature transducer. =
Tightening up the cowl, eliminating the "blow by". Reducing the size of =
the armpit scoops did not change the CHTs, but because I lost the =
airflow over the bottom engine and accessory case, my oil temps are now =
a problem. =20
So, here are two questions for the reflector crowd:
1) How much, if any, cooling air is required for the accessory case and =
oil sump? It's logical that you'd want some, but, OTOH any air down =
there reduces the differential pressure from the plenum / top of the =
engine to the bottom... thereby potentially increasing CHTs. Thoughts? =
BTW, just to get the discussion going, I discussed this extensively with =
the Lycoming rep at OSH, who told me that he didn't think I needed any =
airflow over the sump/accessory case...
2) My cabin heat box is the original, and I've always been unhappy with =
the push/pull cable for the babin heat flapper valve. Anyone put in a =
electrically actuated flapper valve?
To anyone who's acutally read this far... THANKS!
Dave
600+ hours STD-RG N22DN
----- Original Message -----=20
From: Ronnie Brown=20
To: reflector@tvbf.org=20
Sent: Thursday, October 23, 2003 2:02 PM
Subject: Re: REFLECTOR:Heating
I was considering installing electric seat heaters but I decided to =
try a google search for 12vdc electric blankets and look what I found! =
http://www.baproducts.com/rphb1101.htm
Ronnie
----- Original Message -----=20
From: Craig and/or Denise Woolston=20
To: reflector@tvbf.org=20
Sent: Wednesday, October 22, 2003 1:20 AM
Subject: RE: REFLECTOR:Heating
Well I went way overboard but it was one of those great ideas that =
quickly multipled in to lots of hours and it's still not done...
I made two plenums that will mount on canard bulkhead. They each =
have a hot and a cold source coming from front oil cooler and fresh air =
NACA respectively. Since the wife and I are never the same temperature =
a small diverter flap inside each plenum allows for individual =
temperature control. I plan to drill two holes in canard bulkhead that =
each plenum sits over the top. One hole will just allow the output to =
blow down on feet and the other will be routed to the instrument panel =
eyeball vent. Time will only tell if it will work. As for the rear =
seats I'm thinking seriously about electric seat warmers and/or electric =
blanket outlet.=20
Craig
!----------------------------!
! Craig Woolston !
! XL-FG in Palmdale, CA !
! cdwoolston@earthlink.net !
!----------------------------!=20
-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On =
Behalf Of velocityxlfg
Sent: Monday, October 20, 2003 9:07 AM
To: reflector@tvbf.org
Subject: REFLECTOR:Heating
Can some one send me some pictures of what they did on there =
heating system. ducts, Heat exchanger routing of the
heat ducts. Ect.
Ron
velocityxl@fastmail.fm
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<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>I'm fairly new to the reflector, =
so I=20
apologise if this subject has been covered before. I guess I'd be =
a bit=20
surprised if it hadn't...</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I've just passed 600 hours on my =
STD-RG, which I=20
built. I live in Minnesota, and winters are long up here, so I =
always=20
search for good projects to upgrade my aircraft over those long winter=20
months. Last winter I decided to clean up the lower cowl in order =
to=20
improve speed & performance.... you see, my hangar mate is a =
beautiful Cozy=20
3 place. With his 150 horses, he's close (way too close) to =
keeping up=20
with me in my IO-360 powered, 200 HP velocity RG. It's always a =
race when=20
we go flying...</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>My plan was to do drag reduction to the =
lower cowl=20
by reworking the armpit scoops I use for cooling air and eliminating the =
induction air scoop. My airplane's been flying for quite awhile =
now, so=20
I'm sure you guys and the factory have come up with 50 better solutions =
than=20
what use to have... which was the factory standard scoops mounted on the =
cowl,=20
and separate "inner" scoops that were mounted to the sides of the =
fuselage and=20
ducted cooling air to the plenum. I orignally made the inner/outer =
scoop=20
combination to make it easy to remove the lower cowl without having to =
muck with=20
anything. It worked well, but there was quite a gap required =
between the=20
inner fuselage mounted scoops and the cowling. </FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I figured I could reduce the total =
scoop=20
size by about 25% and improve cooling in the process by getting rid =
of the=20
gap. Cooling would be improved given that high pressure air was =
leaking=20
into the lower engine area through the gap... by tightening up the =
outer=20
scoop I would actually increase the differential pressure between the =
plenum and=20
the lower engine area, and also reduce overall drag. At least that =
was the=20
theory. So, I reworked the whole system - I made smaller armpit =
scoops=20
that are mounted to the fuselage, and reformed the cowl to fit tight =
against the=20
new scoops. I faired the new scoops into the cowl so that the =
airflow=20
stays attached as long as possible. Additionally, I made a small =
plenum=20
that provides both engine induction air and cooling air from the right =
hand=20
armpit scoop, thereby eliminating the drag from the separate induction =
air=20
scoop. </FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Results from all this work are very =
mixed... my=20
speed didn't increase at all despite the drag reductions. You may =
laugh at=20
my stupidity on this, but I neglected the fact that by not separating =
the air in=20
the new small cooling/induction air plenum, I lost the ram air effect on =
the=20
induction air side. I lost about 1.5 inches of maximum =
manifold=20
pressure because I didn't separate the induction air from the cooling =
air on the=20
right scoop. Alas, a project for this winter. The real =
problem,=20
though, has been that with this new setup, my oil temps have become very =
difficult to manage. </FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>From a cooling perspective, I've got =
the standard=20
nose mounted oil cooler and cabin heat system. Before the =
modification, my=20
oil temps rarely got up to 100 C (212 F), and my CHTs were all around =
350 F +/-=20
25 degrees. Now, in a climb I can easily heat the oil to redline (242 F) =
if I'm=20
not careful. After much thought and work, it appears that the =
leakage air=20
that was slipping between the inner and outer armpit scoops and =
pressurizing the=20
lower cowl also had a cooling effect on the accessory case, oil sump, =
and the=20
oil temperature transducer. Tightening up the cowl, eliminating =
the "blow=20
by". Reducing the size of the armpit scoops did not change the =
CHTs, but=20
because I lost the airflow over the bottom engine and accessory case, my =
oil=20
temps are now a problem. </FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>So, here are two questions for the =
reflector=20
crowd:</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>1) How much, if any, cooling air is =
required for=20
the accessory case and oil sump? It's logical that you'd want =
some, but,=20
OTOH any air down there reduces the differential pressure from the =
plenum / top=20
of the engine to the bottom... thereby potentially increasing =
CHTs. =20
Thoughts? BTW, just to get the discussion going, I discussed this=20
extensively with the Lycoming rep at OSH, who told me that he didn't =
think I=20
needed any airflow over the sump/accessory case...</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>2) My cabin heat box is the original, =
and I've=20
always been unhappy with the push/pull cable for the babin heat flapper=20
valve. Anyone put in a electrically actuated flapper =
valve?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>To anyone who's acutally read this =
far...=20
THANKS!</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Dave</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>600+ hours STD-RG N22DN</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Dromott@adelphia.net =
href=3D"mailto:romott@adelphia.net">Ronnie=20
Brown</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dreflector@tvbf.org=20
href=3D"mailto:reflector@tvbf.org">reflector@tvbf.org</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Thursday, October 23, =
2003 2:02=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: =
REFLECTOR:Heating</DIV>
<DIV><FONT face=3DArial size=3D2></FONT><BR></DIV>
<DIV><FONT size=3D2>I was considering installing electric seat heaters =
but I=20
decided to try a google search for 12vdc electric blankets and look =
what I=20
found! <A=20
=
href=3D"http://www.baproducts.com/rphb1101.htm">http://www.baproducts.com=
/rphb1101.htm</A></FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Ronnie</FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Dcdwoolston@earthlink.net=20
href=3D"mailto:cdwoolston@earthlink.net">Craig and/or Denise =
Woolston</A>=20
</DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dreflector@tvbf.org=20
href=3D"mailto:reflector@tvbf.org">reflector@tvbf.org</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Wednesday, October 22, =
2003 1:20=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> RE: =
REFLECTOR:Heating</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=3D890350805-22102003><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>Well I went way overboard but it was one of those great =
ideas that=20
quickly multipled in to lots of hours and it's still not=20
done...</FONT></SPAN></DIV>
<DIV><SPAN class=3D890350805-22102003><FONT face=3DArial =
color=3D#0000ff=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D890350805-22102003><FONT face=3DArial =
color=3D#0000ff size=3D2>I=20
made two plenums that will mount on canard bulkhead. They each =
have a=20
hot and a cold source coming from front oil cooler and fresh air =
NACA=20
respectively. Since the wife and I are never the same =
temperature=20
a small diverter flap inside each plenum allows for individual =
temperature=20
control. I plan to drill two holes in canard bulkhead that =
each plenum=20
sits over the top. One hole will just allow the output to blow =
down on=20
feet and the other will be routed to the instrument panel eyeball=20
vent. Time will only tell if it will work. As for the =
rear seats=20
I'm thinking seriously about electric seat warmers and/or electric =
blanket=20
outlet. </FONT></SPAN></DIV>
<DIV><SPAN class=3D890350805-22102003><FONT face=3DArial =
color=3D#0000ff=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D890350805-22102003><FONT face=3DArial =
color=3D#0000ff=20
size=3D2>Craig</FONT></SPAN></DIV>
<DIV><SPAN class=3D890350805-22102003>
<P><FONT size=3D2>!----------------------------!<BR>! Craig=20
=
Woolston  =
; =20
!<BR>! XL-FG in Palmdale, CA !<BR>!=20
cdwoolston@earthlink.net =20
!<BR>!----------------------------!</FONT> </P></SPAN></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff =
2px solid; MARGIN-RIGHT: 0px">
<DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT =
face=3DTahoma=20
size=3D2>-----Original Message-----<BR><B>From:</B> =
reflector-admin@tvbf.org=20
[mailto:reflector-admin@tvbf.org]<B>On Behalf Of=20
</B>velocityxlfg<BR><B>Sent:</B> Monday, October 20, 2003 9:07=20
AM<BR><B>To:</B> reflector@tvbf.org<BR><B>Subject:</B>=20
REFLECTOR:Heating<BR><BR></FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Can some one send me some =
pictures of=20
what they did on there heating system. ducts, Heat exchanger =
routing of=20
the</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>heat ducts. =
Ect.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Ron</FONT></DIV>
<DIV><FONT face=3DArial size=3D2><A=20
=
href=3D"mailto:velocityxl@fastmail.fm">velocityxl@fastmail.fm</A></FONT><=
/DIV></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>
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