 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
Rick S.
Joined: 12 Feb 2006
Posts: 347
Location: Las Vegas
|
 Posted: Tue May 01, 2007 8:51 am Post subject: High Oil Temps |
 |
|
Heres a mod I saw at Sun N fun to redirect the oil cooler air towards the aft opening in the cowl, if you look at the front of the oil cooler you will see a sheet metal curved part that takes the hot air off the cooler air and redirects it to the bottom of the cowl and out the opening...not sure if it helped, the builder seemed to think so. He indicated
that the ideal position for the cooler would be 90 degrees from the firewall, not just tilted down like the stock cooler box.
Rick S.
40185
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
| Description: |
|
| Filesize: |
261.72 KB |
| Viewed: |
185 Time(s) |
|
_________________
Rick S.
RV-10
40185 |
|
| Back to top |
|
 |
KiloPapa
Joined: 24 May 2006
Posts: 142
Location: Pearblossom, CA
|
| Posted: Tue May 01, 2007 9:31 am Post subject: High Oil Temps |
|
|
I appreciate the open discussion and brain-storming regarding the oil temps, oil cooler location, etc.
Keep it going!
Kevin
40494
tail/empennage
do not archive
[quote][b]
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
_________________
Kevin
40494
do not archive |
|
| Back to top |
|
|
Deems Davis
Joined: 09 Jan 2006
Posts: 925
|
| Posted: Tue May 01, 2007 10:17 am Post subject: High Oil Temps |
|
|
Ditto That!
and Thanks Scott for the post regarding the Airflow Performance
conversations and findings, particularly since they appear to be
supported with some data and testing. Rick, the pic of the diverter
duct/shield was intriguing, I wonder if it really helps w/ cooling. I'm
not sure what the velocity of the air is exiting the oil cooler, but as
it hits the duct/shield I would expect some backpressure to be created
which might have an adverse effect on 'pulling' cooling air from the
oil cooler. It seems to me that the most optimum location for the oil
cooler would be 'in-line' with the intake and exit air, with some sort
of a 'venturi' downstream of the oil cooler to compensate for any
airflow loss that occurs through the oil cooler itself. Seems that the
more bends that are put into the path of the airflow, the more the
airflow is restricted and the less efficient it becomes. Fluid dynamics
is magic to me so any insight into this topic is educational.
Regarding the 'louvers' in the bottom of the cowl. They appear to help
with the oil cooling, but I wonder what they are doing to the overall
engine cooling/drag equation? this is another area of 'black magic' and
what I've learned so for is that it's not at all intuitive. there is a
post on VAF from the Lancair list of some in-depth looks into this whole
topic of cooling and airflow.
http://www.vansairforce.com/community/showthread.php?t=17398
Deems Davis # 406
Finishing - ( A Misnomer ! )
http://deemsrv10.com/
KiloPapa wrote:
| Quote: | I appreciate the open discussion and brain-storming regarding the oil
temps, oil cooler location, etc.
Keep it going!
*
*
|
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
|
mritter509(at)msn.com
Guest
|
| Posted: Tue May 01, 2007 3:38 pm Post subject: High Oil Temps |
|
|
Alex does a lot of touch and goes doing transition training in hot Texas
weather. He also has an A/C that probably has some effect on high oil temp.
Mark
N410MR
[quote]From: Scott Schmidt <scottmschmidt(at)yahoo.com>
Reply-To: rv10-list(at)matronics.com
To: rv10-list(at)matronics.com
Subject: Re: High Oil Temps
Date: Tue, 1 May 2007 09:16:37 -0700 (PDT)
I had quite a long conversation with a gentlemen from Airflow Systems
yesterday (I feel bad because I can't remember his name now). They have
developed a new oil cooler that is apparently more efficient than the one
Van's supplies. It is the same dimensions and should bolt directly to the
mount supplied by Van's. From their findings they have seen a decrease in
oil temp of 8-15 degrees.
He is also doing work with an RV-10 out there putting thermal couples all
around the engine and measuring the efficiency of the cooling. He has come
to many of the same conclusions you all have. 1. - Tunnel heat is caused
by the exhaust and not the heating system, and 2. - There needs to be more
outlets on the bottom or side of the cowling. He feels the best location
for more louvers would be on the side of the cowl but the bottom would work
as well. He also feels there is a turbulent area behind the cowl on the
bottom on the plane that is causing some cooling inefficiencies and drag.
(Van would be rolling his eyes if he heard that one. hahaha. He would say
yup, who cares)
Like I mentioned yesterday, I also feel the cooling is decreases due to the
increase of angle of attack caused by 4 people in the aircraft. If I climb
at 105 knots with 2 and 4 people with the exact same power settings but the
oil temp is higher with 4 people there has to be an effect on cooling.
This makes perfect sense. With a higher angle of attack (I will have to
record AOA with 2 and 4 people) there is a slightly higher pressure on the
bottom of the aircraft which will reduce the airflow through the cowl. He
agreed this occurs on all of Van's aircraft. The more weight you have in
the aircraft, the faster IAS you have to fly while climbing to maintain the
same oil temps.
I agree with Tim's statement as well concerning being too cool in the
winter. My temps in the winter are very close to the 165 range so
increasing cooling too much will be bad during those cold months. Seems
like the best scenario is to add louvers to the bottom, possibly add the
more efficient oil cooler and in the winter I will have to add the oil
cooler shutter from Vans.
http://www.vansaircraft.com/cgi-bin/catalog.cgi?ident=1178035620-106-414&browse=engines&product=oil_shutter
The more I talk with people though, the more I am finding lots of people
are dealing this issue. Alex in Texas has 2 oil coolers on his RV-10 and
is now switching to the new oil cooler from Airflow Systems.
Scott Schmidt
scottmschmidt(at)yahoo.com
---
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
|
AV8ORJWC
Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"
|
| Posted: Tue May 01, 2007 7:06 pm Post subject: High Oil Temps |
|
|
The archives are full of the posted problem causes and correction possibilities to this dilemma. I forwarded to Tim a great On Demand Video series from Lycoming on the importance of oil and its handling to be placed at RV University. It is worth your time to review. Keep your oil level UP.
1. There was, is and will remain to be several factors affecting unusual operating temperatures. The first point is that aluminum engine components do not like high temperatures. I have a lower threshold for acceptable operating temperature than several readers so I will not expound or rehash.
2. The aircraft in a “High Alpha” or High angle of attack configuration changes the flow (negatively) into the forward cooling openings and changes the relative airflow over and extraction of discharged heat in the lower cowl (out the bottom). Draw yourself an airflow diagram and you will see how bends and contortions make little sense.
3. The material used in transporting High Pressure /Lower temperature ambient airflow to the oil heat exchanger is of importance. I was hopeful that a few HVAC specialist would pipe up on the obvious area for improvement in the VAN designed Scat system.
4. Dan Checkoway has posted the value in improved flow heat exchangers and the inherent cracking of exchanger mounts as designed and plans built – the baffle material takes a tremendous shock – so DSS balance your engine (and your avionics will love you too). Learn from Dan’s posts too.
Answer to #1. Reduce the number of constricting 90 degree duct bends by creating your own – improved airflow duct system. Consider leaving the cheap, available and easy to buy Scat tubing and consider a two BID composite smooth wall distribution plenum. To keep your temperatures lower, move to a more temperate locale like one that rains frequently and has little sunlight. I am a strong proponent of Forsling Exhaust and ceramic coating them ( ie. Scott Schmidt).
Answer to #2, choose to keep guys like me out of the back seat and keep your nose low in a low and passive state of climb - under 115 knots. (that is NOT why I bought the RV-10). I want to climb like a bandit and get out of Dodge in a hurry. You can design that feature back into your cowl and your airflow distribution system – Simply.
Answer #3 Insulate your composite duct To and From the heat exchanger.
Answer #4 Get a more efficient exchanger while you are doing mods as Dan did.
Now back to the diatribe. Three 90 degree elbows (that equals 270 degrees of contortion) and trying to force the Heat Exchanger duct forward into a direct opposition of high pressure 115 mph air /heated flow downward and aft from over the cylinder fins is not “brilliant aerodynamic design”. Think about trying to blow into a 2.5” scat tube sticking out the window of your car at 100 mph. Take it upon yourself to create a mount bracket and exchanger orientation which works at the most important time – Climb configuration. Consider studying why the James High Pressure Induction Plenum can be of value over a plans built variant. Again, my past posts stated that cooling is enhanced by Delta P and Delta T. Pressure Differential and Temperature Differential between the upper and lower decks. I am not a proponent of solely the louvers but they are a half hearted attempt at a correction for a known problem. Design the direction and capture of ambient airflow for the ‘High Alpha’ configuration. Draw a simple cartoon of the airflow path into and out of your aircraft while in High Alpha – again think about blowing out the window of your cabin. Cruise configuration will take care of itself. Assist the flow with logical and smooth curves into and out of the exchanger. If doing louvers, then make them so they are designed for High Alpha orientation. Yes, the positive pressure increases on the bottom (the more reduced pressure of the lower cowl negates) against the change over the top (when in High Alpha). This reduces, negates or defeats the affective extraction of convective airflow in comparison to cruise. Hence – augmenters.
Keep your oil clean and up to the right level. Keep building.
John Cox #600 in 2015 or about. (Oh and I do have a CHT number for “Houston we have a problem” ) Kelly this is your cue to pipe in here!
PS – the aluminum can talk back and top ends are expensive but that is what maintenance is for… right? I also like the ability to run LOP so I can save the fuel for ROP in High Alpha.
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of KiloPapa
Sent: Tuesday, May 01, 2007 10:30 AM
To: rv10-list(at)matronics.com
Subject: Re: High Oil Temps
I appreciate the open discussion and brain-storming regarding the oil temps, oil cooler location, etc.
Keep it going!
Kevin
40494
tail/empennage
do not archive
[quote] [b]
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
|
scottmschmidt(at)yahoo.co
Guest
|
| Posted: Tue May 01, 2007 7:52 pm Post subject: High Oil Temps |
|
|
I have also been meaning to ask about synthetic oil. I have read posts on advrider.com about people switching to synthetic oil and seeing lower oil temperatures on their air-cooled BMW bikes.
Has anyone had a similar experience? I now have 160 hours on my engine and I am planning on switching to synthetic on my next change.
Scott Schmidt
scottmschmidt(at)yahoo.com
---
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
|
Tim Olson
Joined: 25 Jan 2007
Posts: 2882
|
| Posted: Tue May 01, 2007 8:28 pm Post subject: High Oil Temps |
|
|
I did see a slight drop at 100 hours when I went to Exxon Elite from
Philips. I don't think anyone recommends a full synthetic for the
aircraft engines as far as I know, but the synthetic blends have a
good reputation.
Tim Olson - RV-10 N104CD - Flying
do not archive
Scott Schmidt wrote:
[quote] I have also been meaning to ask about synthetic oil. I have read posts
on advrider.com about people switching to synthetic oil and seeing lower
oil temperatures on their air-cooled BMW bikes.
Has anyone had a similar experience? I now have 160 hours on my engine
and I am planning on switching to synthetic on my next change.
Scott Schmidt
scottmschmidt(at)yahoo.com
---
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
|
speckter(at)comcast.net
Guest
|
| Posted: Wed May 02, 2007 5:29 am Post subject: High Oil Temps |
|
|
This thought occurred to me also. I have a genset on my motor home that runs hot. I changed to synthetic oil and it runs cooler. Should work on Lycs too.
Gary
40274
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Scott Schmidt
Sent: Tuesday, May 01, 2007 10:52 PM
To: rv10-list(at)matronics.com
Subject: Re: High Oil Temps
I have also been meaning to ask about synthetic oil. I have read posts on advrider.com about people switching to synthetic oil and seeing lower oil temperatures on their air-cooled BMW bikes.
Has anyone had a similar experience? I now have 160 hours on my engine and I am planning on switching to synthetic on my next change.
Scott Schmidt
scottmschmidt(at)yahoo.com
----- Original Message ----
From: John W. Cox <johnwcox(at)pacificnw.com>
To: rv10-list(at)matronics.com
Sent: Tuesday, May 1, 2007 6:04:49 PM
Subject: RE: High Oil Temps
The archives are full of the posted problem causes and correction possibilities to this dilemma. I forwarded to Tim a great On Demand Video series from Lycoming on the importance of oil and its handling to be placed at RV University. It is worth your time to review. Keep your oil level UP.
1. There was, is and will remain to be several factors affecting unusual operating temperatures. The first point is that aluminum engine components do not like high temperatures. I have a lower threshold for acceptable operating temperature than several readers so I will not expound or rehash.
2. The aircraft in a “High Alpha” or High angle of attack configuration changes the flow (negatively) into the forward cooling openings and changes the relative airflow over and extraction of discharged heat in the lower cowl (out the bottom). Draw yourself an airflow diagram and you will see how bends and contortions make little sense.
3. The material used in transporting High Pressure /Lower temperature ambient airflow to the oil heat exchanger is of importance. I was hopeful that a few HVAC specialist would pipe up on the obvious area for improvement in the VAN designed Scat system.
4. Dan Checkoway has posted the value in improved flow heat exchangers and the inherent cracking of exchanger mounts as designed and plans built – the baffle material takes a tremendous shock – so DSS balance your engine (and your avionics will love you too). Learn from Dan’s posts too.
Answer to #1. Reduce the number of constricting 90 degree duct bends by creating your own – improved airflow duct system. Consider leaving the cheap, available and easy to buy Scat tubing and consider a two BID composite smooth wall distribution plenum. To keep your temperatures lower, move to a more temperate locale like one that rains frequently and has little sunlight. I am a strong proponent of Forsling Exhaust and ceramic coating them ( ie. Scott Schmidt).
Answer to #2, choose to keep guys like me out of the back seat and keep your nose low in a low and passive state of climb - under 115 knots. (that is NOT why I bought the RV-10). I want to climb like a bandit and get out of Dodge in a hurry. You can design that feature back into your cowl and your airflow distribution system – Simply.
Answer #3 Insulate your composite duct To and From the heat exchanger.
Answer #4 Get a more efficient exchanger while you are doing mods as Dan did.
Now back to the diatribe. Three 90 degree elbows (that equals 270 degrees of contortion) and trying to force the Heat Exchanger duct forward into a direct opposition of high pressure 115 mph air /heated flow downward and aft from over the cylinder fins is not “brilliant aerodynamic design”. Think about trying to blow into a 2.5” scat tube sticking out the window of your car at 100 mph. Take it upon yourself to create a mount bracket and exchanger orientation which works at the most important time – Climb configuration. Consider studying why the James High Pressure Induction Plenum can be of value over a plans built variant. Again, my past posts stated that cooling is enhanced by Delta P and Delta T. Pressure Differential and Temperature Differential between the upper and lower decks. I am not a proponent of solely the louvers but they are a half hearted attempt at a correction for a known problem. Design the direction and capture of ambient airflow for the ‘High Alpha’ configuration. Draw a simple cartoon of the airflow path into and out of your aircraft while in High Alpha – again think about blowing out the window of your cabin. Cruise configuration will take care of itself. Assist the flow with logical and smooth curves into and out of the exchanger. If doing louvers, then make them so they are designed for High Alpha orientation. Yes, the positive pressure increases on the bottom (the more reduced pressure of the lower cowl negates) against the change over the top (when in High Alpha). This reduces, negates or defeats the affective extraction of convective airflow in comparison to cruise. Hence – augmenters.
Keep your oil clean and up to the right level. Keep building.
John Cox #600 in 2015 or about. (Oh and I do have a CHT number for “Houston we have a problem” ) Kelly this is your cue to pipe in here!
PS – the aluminum can talk back and top ends are expensive but that is what maintenance is for… right? I also like the ability to run LOP so I can save the fuel for ROP in High Alpha.
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of KiloPapa
Sent: Tuesday, May 01, 2007 10:30 AM
To: rv10-list(at)matronics.com
Subject: Re: High Oil Temps
I appreciate the open discussion and brain-storming regarding the oil temps, oil cooler location, etc.
Keep it going!
Kevin
40494
tail/empennage
do not archive
| Quote: | | http://www.matronics.com/Navigator?RV10-Listhttp://forums.matronics.com "http://forums.matronics.com/" target=_blank rel=nofollow>http://forums================== |
| Quote: | | "http://forums.matronics.com/" target=_blank rel=nofollow>http://forums================== |
0 | Quote: | | "http://forums.matronics.com/" target=_blank rel=nofollow>http://forums================== |
1 | Quote: | | "http://forums.matronics.com/" target=_blank rel=nofollow>http://forums================== |
2 | Quote: | | "http://forums.matronics.com/" target=_blank rel=nofollow>http://forums================== |
3 | Quote: | | "http://forums.matronics.com/" target=_blank rel=nofollow>http://forums================== |
4 | Quote: | | "http://forums.matronics.com/" target=_blank rel=nofollow>http://forums================== |
5 | Quote: | | "http://forums.matronics.com/" target=_blank rel=nofollow>http://forums================== |
6 | Quote: | | "http://forums.matronics.com/" target=_blank rel=nofollow>http://forums================== |
7
[quote][b]
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
