REFLECTOR:High Taxi And Hold Temps.
Chuck Jensen
reflector@tvbf.org
Mon, 12 Jan 2004 15:04:49 -0500
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As usual, Ronnie's right. My XLRG (Prudhomme) has real tight baffles that
go all the way to the underside of the fins on the heads. There's precious
little escape route for the air from the top NACAs except through the fins.
On the right side of the lower cowl, mine is set up with a small NACA on the
cowl which must be intended to introduce some air into the lower engine
compartment to help "flush" the hot air out of the compartment. Have no
idea if it helps (and will not help on the ground) but I get numbers similar
to Ronnie's. It seems the common denominator for cooler running unit is a
good plenum with great baffling.
Chuck Jensen
-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On Behalf Of
Ronnie Brown
Sent: Monday, January 12, 2004 1:47 PM
To: reflector@tvbf.org
Subject: Re: REFLECTOR:High Taxi And Hold Temps.
Like Scott mentioned yesterday, a key consideration for cooling this pusher
is to make sure the engine cylinder baffles are correctly installed - no
gaps at the crankcase. Also, make sure the wraps go around the bottom of
the cylinder and only leave about 1.5 to 2" gaps at the bottom of he
cylinders and heads for the air to exit from the cylinders. This sounds
restrictive, but IT WORKS. It keeps the air flowing THROUGH the fins with
good velocity. Also make certain that there is a wrap on the back of #4
(right, forward cylinder), because the Velocity supplied plenum leaves this
area very open.
My NACA top inlets on my 173 Elite RG with Lycoming IO360 C1C (angle valve
engine), will stay under 320-330 CHT's while taxiing, holding, etc.
On climb out, the hottest I have ever seen is 370-380 CHT and all I have to
do is add airspeed, i.e., instead of 100 knot climb, reduce climb to 120-130
knots, and the temps go back down. I did not have to seal my plenums with
RTV but I did lay up 2 BID from the plenum onto duct taped cylinder block to
close up the gaps.
My cruise CHT's are 320 - 360 degrees depending on RPM's and leaning. My
oil temps stay under 210 on hot days, and runs 180-190 on cool days. I have
good heat coming from my oil cooler too. I haven't flown below 40 degrees,
but I have to just about close off the heater to keep from getting too warm
in the cabin. I have taken care to close up the gaps around the elevator
torque tubes and closing up the space between the top of the canard and the
canard cover.
I am very pleased with my Velocity engine cooling. I expected troubles from
talking to other Velocity builders, but I have really been very pleasantly
surprised with how well it works. Mark Machado had similar success with his
173 (now the standard factory trainer) when he changed from arm pit to top
NACA scoops. I also noted that Mark had built BID wraps for the bottom of
his plenums. Mine are Stainless Steel, but it doesn't matter what they are
made of (aluminum will work too), make sure you have wraps on the bottom of
the cylinders.
Incidentally, I have noticed that my front cylinders (3&4) run warm at
higher speeds and the rear ones (1&2) run warmer at lower speeds. So I have
not done anything to balance flows. Works good like it is.
Ronnie Brown
N713MR 110 hours
http://home.sprintmail.com/~rolandbrown/page10.html
<http://home.sprintmail.com/~rolandbrown/page10.html>
----- Original Message -----
From: MikeWatsonSpg@cs.com <mailto:MikeWatsonSpg@cs.com>
To: reflector@tvbf.org <mailto:reflector@tvbf.org>
Sent: Monday, January 12, 2004 1:04 PM
Subject: REFLECTOR:High Taxi And Hold Temps.
Does anyone else have any theories to alleviate the long taxi and hold heat
situation?
Mike
Hi Mike
I confess to having those chimney hopes as well. I expanded the oil door
opening to about a 1 foot by 1.5 foot opening, so I could do a better
pre-flight check and occasionally wonder about running a cable back there to
pop it open while I'm sitting on the ground as the cowling sure traps in the
heat. I am pulling some ideas together to put in two small scoops on the
belly to run air directly at the fins of cylinders 5 &6. as they just get
too hot in climbing out, but I don't think that will do anything much to aid
cooling when I'm sitting on the ground... but who knows.
Rodney Brim, Ph.D.
CEO, Performance Solutions Technology, LLC
Delivering goal+plan based technology/processes for highly coordinated and
accountable management teams
www.performancesolutionstech.com <http://www.performancesolutionstech.com/>
or www.managepro.com <http://www.managepro.com/>
Ph. (562) 799-1267
-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On Behalf Of
MikeWatsonSpg@cs.com
Sent: Sunday, January 11, 2004 3:48 PM
To: reflector@tvbf.org
Subject: Re: REFLECTOR: Frankliln/IVO High Temps
Thanks Rodney,
I also have 10.5:1 ratio. If I have to hold for more than 15 minutes on a 85
degree
day, my CHT's approach 385 F. Usually I have to pull off at the run up area,
shut
down for at lease 15 minutes.
I thought the heat would escape up through the ducks and out the nacca while
idling, like a chimney draft. I guess I was wrong.
Mike Watson
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<DIV><SPAN class=375165519-12012004><FONT face=Arial color=#0000ff size=2>As
usual, Ronnie's right. My XLRG (Prudhomme) has real tight baffles that go
all the way to the underside of the fins on the heads. There's precious
little escape route for the air from the top NACAs except through the
fins. On the right side of the lower cowl, mine is set up with a small
NACA on the cowl which must be intended to introduce some air into the lower
engine compartment to help "flush" the hot air out of the compartment.
Have no idea if it helps (and will not help on the ground) but I get numbers
similar to Ronnie's. It seems the common denominator for cooler running
unit is a good plenum with great baffling.</FONT></SPAN></DIV>
<P><FONT face=Arial size=2>Ch</FONT><FONT face=Arial size=2>uck</FONT><FONT
face=Arial size=2> Jensen</FONT> </P>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> reflector-admin@tvbf.org
[mailto:reflector-admin@tvbf.org]<B>On Behalf Of </B>Ronnie
Brown<BR><B>Sent:</B> Monday, January 12, 2004 1:47 PM<BR><B>To:</B>
reflector@tvbf.org<BR><B>Subject:</B> Re: REFLECTOR:High Taxi And Hold
Temps.<BR><BR></FONT></DIV>
<DIV><FONT size=2>Like Scott mentioned yesterday, a key consideration for
cooling this pusher is to make sure the engine cylinder baffles are correctly
installed - no gaps at the crankcase. Also, make sure the wraps go
around the bottom of the cylinder and only leave about 1.5 to 2" gaps at the
bottom of he cylinders and heads for the air to exit from the cylinders.
This sounds restrictive, but IT WORKS. It keeps the air flowing THROUGH
the fins with good velocity. Also make certain that there is a wrap on
the back of #4 (right, forward cylinder), because the Velocity supplied plenum
leaves this area very open.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>My NACA top inlets on my 173 Elite RG with Lycoming IO360
C1C (angle valve engine), will stay under 320-330 CHT's while taxiing,
holding, etc. </FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>On climb out, the hottest I have ever seen is 370-380 CHT
and all I have to do is add airspeed, i.e., instead of 100 knot climb, reduce
climb to 120-130 knots, and the temps go back down. I did not have to
seal my plenums with RTV but I did lay up 2 BID from the plenum onto duct
taped cylinder block to close up the gaps.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>My cruise CHT's are 320 - 360 degrees depending on RPM's and
leaning. My oil temps stay under 210 on hot days, and runs 180-190 on
cool days. I have good heat coming from my oil cooler too. I
haven't flown below 40 degrees, but I have to just about close off the heater
to keep from getting too warm in the cabin. I have taken care to close
up the gaps around the elevator torque tubes and closing up the
space between the top of the canard and the canard cover. </FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I am very pleased with my Velocity engine cooling. I
expected troubles from talking to other Velocity builders, but I have really
been very pleasantly surprised with how well it works. Mark Machado had
similar success with his 173 (now the standard factory trainer) when he
changed from arm pit to top NACA scoops. I also noted that Mark had
built BID wraps for the bottom of his plenums. Mine are Stainless Steel,
but it doesn't matter what they are made of (aluminum will work too), make
sure you have wraps on the bottom of the cylinders.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Incidentally, I have noticed that my front cylinders
(3&4) run warm at higher speeds and the rear ones
(1&2) run warmer at lower speeds. So I have not done
anything to balance flows. Works good like it is.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Ronnie Brown</FONT></DIV>
<DIV><FONT size=2>N713MR 110 hours</FONT></DIV>
<DIV><FONT size=2><A
href="http://home.sprintmail.com/~rolandbrown/page10.html">http://home.sprintmail.com/~rolandbrown/page10.html</A></FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=MikeWatsonSpg@cs.com
href="mailto:MikeWatsonSpg@cs.com">MikeWatsonSpg@cs.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=reflector@tvbf.org
href="mailto:reflector@tvbf.org">reflector@tvbf.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, January 12, 2004 1:04
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> REFLECTOR:High Taxi And Hold
Temps.</DIV>
<DIV><BR></DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial size=2
PTSIZE="10" FAMILY="SANSSERIF">Does anyone else have any theories to
alleviate the long taxi and hold heat
situation?<BR><BR>Mike<BR><BR><BR><BR>Hi Mike</FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 size=3
PTSIZE="12" FAMILY="SANSSERIF" BACK="#ffffff"><BR></FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 size=2
PTSIZE="10" FAMILY="SANSSERIF" BACK="#ffffff">I confess to having those
chimney hopes as well. I expanded the oil door opening to about a 1 foot by
1.5 foot opening, so I could do a better pre-flight check and occasionally
wonder about running a cable back there to pop it open while I'm sitting on
the ground as the cowling sure traps in the heat. I am pulling some ideas
together to put in two small scoops on the belly to run air directly at the
fins of cylinders 5 &6. as they just get too hot in climbing out, but I
don't think that will do anything much to aid cooling when I'm sitting on
the ground... but who knows.</FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 size=3
PTSIZE="12" FAMILY="SANSSERIF" BACK="#ffffff"><BR><BR></FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000080 size=4
PTSIZE="14" FAMILY="SANSSERIF" BACK="#ffffff"><B>Rodney Brim,
Ph.D.</FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial
color=#000000 size=3 PTSIZE="12" FAMILY="SANSSERIF"
BACK="#ffffff"></B><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff"
face=Tahoma color=#000000 size=2 PTSIZE="10" FAMILY="SANSSERIF"
BACK="#ffffff">CEO, Performance Solutions Technology, LLC</FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Tahoma color=#000000 size=3
PTSIZE="12" FAMILY="SANSSERIF" BACK="#ffffff"><BR></FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Tahoma color=#000000 size=1
PTSIZE="8" FAMILY="SANSSERIF" BACK="#ffffff">Delivering goal+plan based
technology/processes for highly coordinated and accountable management
teams</FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Tahoma
color=#000000 size=3 PTSIZE="12" FAMILY="SANSSERIF"
BACK="#ffffff"><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff"
face=Tahoma color=#0000ff size=1 PTSIZE="8" FAMILY="SANSSERIF"
BACK="#ffffff"><A
href="http://www.performancesolutionstech.com/">www.performancesolutionstech.com</A>
or <A href="http://www.managepro.com/">www.managepro.com</A></FONT><FONT
lang=0 style="BACKGROUND-COLOR: #ffffff" face=Tahoma color=#000000 size=3
PTSIZE="12" FAMILY="SANSSERIF" BACK="#ffffff"><BR></FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Tahoma color=#000000 size=1
PTSIZE="8" FAMILY="SANSSERIF" BACK="#ffffff">Ph. (562) 799-1267</FONT><FONT
lang=0 style="BACKGROUND-COLOR: #ffffff" face=Tahoma color=#000000 size=3
PTSIZE="12" FAMILY="SANSSERIF" BACK="#ffffff"><BR></FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 size=2
PTSIZE="10" FAMILY="SANSSERIF" BACK="#ffffff"><BR></FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Tahoma color=#000000 size=2
PTSIZE="10" FAMILY="SANSSERIF" BACK="#ffffff">
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px solid; MARGIN-RIGHT: 0px"
TYPE="CITE">-----Original Message-----<BR><B>From:</B>
reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]<B>On Behalf Of
</B>MikeWatsonSpg@cs.com<BR><B>Sent:</B> Sunday, January 11, 2004 3:48
PM<BR><B>To:</B> reflector@tvbf.org<BR><B>Subject:</B> Re: REFLECTOR:
Frankliln/IVO High Temps<BR><BR></FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Tahoma color=#000000 size=3
PTSIZE="12" FAMILY="SANSSERIF" BACK="#ffffff"><BR></FONT><FONT lang=0
style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 size=2
PTSIZE="10" FAMILY="SANSSERIF" BACK="#ffffff">Thanks Rodney,<BR><BR>I also
have 10.5:1 ratio. If I have to hold for more than 15 minutes on a 85
degree<BR>day, my CHT's approach 385 F. Usually I have to pull off at the
run up area, shut<BR>down for at lease 15 minutes.<BR><BR>I thought the
heat would escape up through the ducks and out the nacca while<BR>idling,
like a chimney draft. I guess I was wrong.<BR><BR>Mike Watson
</BLOCKQUOTE><BR></BLOCKQUOTE></BLOCKQUOTE></FONT></FONT></BODY></HTML>
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