Matronics Email Lists :: View topic - Cooling issues XS 914 on the ground

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Cooling issues XS 914 on the ground
Goto page 1, 2 Next

Matronics Email Lists Forum Index -> Europa-List

View previous topic :: View next topic

Author Message

Remi Guerner

Joined: 14 Dec 2010
Posts: 284

Posted: Sat Aug 20, 2016 1:22 am Post subject: Cooling issues XS 914 on the ground

Roland,

I am surprised to learn that you have a 7 row oil cooler as I thought the standard XS installation was with a 13 row.  At least this is what I have on my XS and I had to mask the major part of it to get the proper oil temp, even in summer.  I am planning to install a smaller one, either the 10 or 7 row, but was afraid of the increased pressure drop caused by the reduced oil section of the smaller one. 

Could other XS drivers tell me what size oil cooler they are using? 13,10 or 7 rows?

 Regards

Remi

F-PGKL



<<<<<<<below the radiator for the 7-row-oilcooler mounted behind the radiator,

4 rows overlapping with it. >>>>>>>>

h&jeuropa

Joined: 07 Nov 2006
Posts: 645

Posted: Sat Aug 20, 2016 5:57 am Post subject: Re: Cooling issues XS 914 on the ground

Remi,



Our oil cooler has 10 rows and that works fine in summer.  In the winter we sometimes mask off (cover) 3 or 4 rows.  First time we did this, we flew in Spring and the oil temp was getting way too hot (in Michigan). Ours is an XS.



Jim & Heather

h&jeuropa

Joined: 07 Nov 2006
Posts: 645

Posted: Sat Aug 20, 2016 10:12 am Post subject: Re: Cooling issues XS 914 on the ground

CORRECTION!  Ours is also a 13 row oil cooler.  I based the previous answer on a photo where part of the cooler was actually hidden from view.  We were just at the airport and verified.  When we mask off, there are 6-7 rows showing.  



Sorry for any confusion.  Heather

Fred Klein

Joined: 26 Mar 2012
Posts: 503

Posted: Sat Aug 20, 2016 12:13 pm Post subject: Cooling issues XS 914 on the ground

As an aside to this conversation…can anyone tell me the ratio of the area of the inlet to the area of the face of the radiator? 



This would be of interest as I grapple w/ cooling issues related to my non-standard engine install (a MPEFI, liquid cooled, 1.8L RAM Sube.



thanks in advance,



Fred



 	  Quote: 	
		   On Aug 20, 2016, at 11:12 AM, h&amp;jeuropa <butcher43(at)att.net> wrote:

 

 

 

 CORRECTION!  Ours is also a 13 row oil cooler.  I based the previous answer on a photo where part of the cooler was actually hidden from view.  We were just at the airport and verified.  When we mask off, there are 6-7 rows showing.  

 

 Sorry for any confusion.  Heather

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=459689#459689

Roland

Joined: 30 Nov 2009
Posts: 334
Location: EDLE

Posted: Sun Aug 21, 2016 9:28 pm Post subject: Re: Cooling issues XS 914 on the ground

Remi,



I can tell you, that the 7-row oil cooler in my setup is sufficient under ALL conditions. That also (like many other things I've learned about cooling) is far from logical, since I always had the oil too hot in summer even in cruise climb 90KIAS with the 13-row cooler (which I donated to the Europa Club  ) when it was installed in tandem with the radiator previously.



Now I only left a gap of just 1 cm below the radiator with an aluminum sheet installed in the tunnel, so that I have in sum the radiator surface and this 1 cm gap below, where all air has to pass through in the tunnel. The oil cooler has now 4 rows overlapping behind the radiator and only 3 rows get cool air from this 1 cm gap. 



In addition the aluminum sheet in the tunnel, which guides the air through the radiator extends behind the oil cooler, so that no cool air is lost below the oil cooler.



Regards

Roland

PH-ZTI

XS TG 914

nigel_graham(at)m-tecque.
Guest

Posted: Mon Aug 22, 2016 5:10 am Post subject: Cooling issues XS 914 on the ground

Hi Fred,

I waited for more informed respondents but it's all gone eerily quiet. 

As you are aware, I have developed my own cowling and cooling ducting - 

so have spent a lot of time researching this problem.

There is no prescribed ratio as such. The dimensions will be defined by 

the aircraft speed at which the cooling should be most efficient 

(climbing, full power - probably around 80kts (41 m/s) and the speed at 

which you can get air through the radiator (a lot less than 41 m/s - 

your radiator manufacturer should be able to supply this data). In the 

cruise of around 120 kts, the air will be whistling by at about 62m/s.

The surface area of the radiator is dictated by the amount of heat you 

need to dump (you'll get this from your engine supplier), though I guess 

you've already sourced a rad.

The purpose of the divergent duct (a diffuser) is to slow the air down 

and raise it's pressure, before presenting it to the radiator at a speed 

that can be passed through the radiator matrix that is fast enough to 

absorb the heat, but not so fast that the airflow stalls and causes drag 

(like the standard Europa). So the eventual size of the duct opening 

will be arrived at using a ratio of flying speed to 

best-airflow-through-rad speed.

The next bit sounds simple - just make up a divergent duct to join the 

opening to the radiator ........ but as in all things aviation, there's 

a "gotcha". The diffuser walls cannot diverge more than 7.0 degrees from 

the free airstream (deduced buy experiment and verified by subsequent 

CFD analysis), or the boundary layer breaks away and goes turbulent - 

causing huge cooling drag. Once the air has cleared the radiator, it 

needs to be speeded up again and it's pressure reduced to rejoin the 

outside air at as near as possible, the same pressure (pressure 

recovery) any miss-match here will cause drag This is done by passing it 

through a convergent duct (a nozzle). Since the air is being forced into 

a reducing cross section, it can withstand a far sharper convergent 

angle before the boundary layer goes turbulent - typically around 15 to 

25 degrees. (have you ever noticed the different inlet/outlet cone 

angles of a vintage aircraft venturi?)

How much you need to slow your air down dictates how long your 

narrow-angle duct should be. In my case it was about 2.5m - putting the 

radiator just in front of the tailplane, clearly not a viable option. I 

had to get the air into my cowl, slow it down, pass it through the 

radiator, speed it up and exhaust it in just under 600mm. in the space 

in the centre tunnel. I think I have devised a way of meeting all of 

these requirements within the challenging space constraints, though as I 

haven't been able to test it out yet, will keep it under my hat for the 

time being!

Hope this is of some help.

Nigel

On 20/08/2016 20:49, Fred Klein wrote:

 	  Quote: 	

 As an aside to this conversation…can anyone tell me the ratio of the area of the inlet to the area of the face of the radiator?

 This would be of interest as I grapple w/ cooling issues related to my non-standard engine install (a MPEFI, liquid cooled, 1.8L RAM Sube.

 thanks in advance,

 Fred

> On Aug 20, 2016, at 11:12 AM, h&amp;jeuropa <butcher43(at)att.net> wrote:

>

> 

>

> CORRECTION!  Ours is also a 13 row oil cooler.  I based the previous answer on a photo where part of the cooler was actually hidden from view.  We were just at the airport and verified.  When we mask off, there are 6-7 rows showing.

>

> Sorry for any confusion.  Heather

>

>

> Read this topic online here:

>

> http://forums.matronics.com/viewtopic.php?p=459689#459689

>

>

Fred Klein

Joined: 26 Mar 2012
Posts: 503

Posted: Mon Aug 22, 2016 10:44 am Post subject: Cooling issues XS 914 on the ground

 	  Quote: 	
		  On Aug 22, 2016, at 5:52 AM, nigel_graham(at)m-tecque.co.uk (nigel_graham(at)m-tecque.co.uk) wrote:

I waited for more informed respondents but it's all gone eerily quiet. As you are aware, I have developed my own cowling and cooling ducting - so have spent a lot of time researching this problem.

	


Nigel…thank you for your thoughtful (and informed) reply…I’m aware of the “7% solution” to the flow in the inlet duct and issues related to the desire for non-turbulent flow. I will respond to your message w/ photos and comment, perhaps best handled w/ a personal email since out discussion will focus on non-standard engine/cowl combinations.



Fred

frans(at)privatepilots.nl
Guest

Posted: Mon Aug 22, 2016 6:43 pm Post subject: Cooling issues XS 914 on the ground

-----BEGIN PGP SIGNED MESSAGE-----

Hash: SHA1



Hi Nigel,



 	  Quote: 	
		   The purpose of the divergent duct (a diffuser) is to slow the air

 down and raise it's pressure, before presenting it to the radiator

 at a speed that can be passed through the radiator matrix that is

 fast enough to absorb the heat, but not so fast that the airflow

 stalls and causes drag (like the standard Europa).


	


You describe a divergent diffuser. Later it was discovered that you

can also make a wedge diffuser, by placing the radiator at a steep

angle, and a horizontal sheet of metal meeting the end of the

radiator. This accomplishes the same effect, slowing the air down and

increasing the pressure. The air goes indeed into turbulent flow, but

this is just what you want inside the radiator; turbulent air carries

heat more easily away. One of my experiments was to use the original

radiators but in a wedge setup and it gave a huge improvement, while

the required radiator opening was much less.

A later discovery (not by me but in general) was that you can also

create a natural wedge diffuser by placing the radiator at an angle...

and leaving the horizontal separator away. This simply means you can

mount the radiator inline with the angled shape of the lower cowling.

It sounds a bit strange at first sight, but once you realize that the

function of a diffuser is to convert a small opening with high speed

air to a large opening with low speed and higher pressure, you will

see that the same happens with a very steeply angled radiator in free

air. The frontal surface is much smaller than the surface of the radiator.

Thinking like air molecules: hitting the radiator they are scooped up,

to pass through them, but when there is no more room for air molecules

the remaining air molecules just see a solid angled "plate" and just

follow the shape of the lower cowling as if there is no radiator at

all, so it causes no drag.



Anyway, it works perfectly well. And it is done this way in many

modern aircraft.



Hope this gives further insight.



Greetings,

Frans



-----BEGIN PGP SIGNATURE-----

Version: GnuPG v2.0.22 (GNU/Linux)



iQIcBAEBAgAGBQJXu7eAAAoJEC+zXxqs0ZzV7g4P/A+I/DD1uHqugMzrBJ6loFbw

NC2ohqjMV9CkUBZf+/2Nk+By8bIIu+NY/swwYImr6TDly6obF3XrrTUWoZg2ukZ9

E2y1+F3YZFoC82mZkCBq9seuyrpz1U3kdoZI3D/J2oBC3GVEqzmNTr17Rim4H2zT

oIl01tjRD8GUh2dii7HEzHqShUV/sYJoq9Z6sBN1CAOR26rEfga2iwtMZrE81ziV

9PIIPFEXc/P9dXSd3sRetEbtdx0XQpWOYP3CTXROQGNzta+SteiiqSOI+wOFz5m3

tg6lwX66RraqNmM23DsrvgTUFQRPNeaaSeIbOrmdXM5p5hZwkKCPlwUJsOaVFMDn

iyOC4ShP1wObEq+GT2m1FfdGxJRrXzLZy2l5sJkgd2azsNAIm9KQqqr+5oaLBjsq

UKT/LnRHPgnfsSI9Ui4Cohhi+kpyR3EQbkP0+q2wmRSGlW8F2XlIC1+oMELarYxt

nuP8q6m7XMY1iYWaNzF8Mtmuyh4z6CgP01rCqRk2XmSLE2o9LFwsDMM6lq/RT5h1

WfCEiIA4Jq6//sL6B/qPmxBmXWNRXXHi2E/+jKxWRVlWtLt4ksaxkKdTqyHoQPRT

iSLxrO1e0aKNTzOdbWetcc9bhC8K9GFUWAa48x6i33QsLdtenLz+gFP/+nwbj2xZ

8u9wkPetJcXOQZjGXmm1

=tc31

-----END PGP SIGNATURE-----

Remi Guerner

Joined: 14 Dec 2010
Posts: 284

Posted: Tue Aug 23, 2016 11:16 am Post subject: Re: Cooling issues XS 914 on the ground

The dimensions will be defined by 

the aircraft speed at which the cooling should be most efficient 

(climbing, full power - probably around 80kts (41 m/s) 

Hi Nigel,

One common issue with the Europa is overheating on the ground, not in flight. It is very tempting to optimize a cowling design for low drag as you did but are you sure that such a design will allow the engine to be run indefinitely at idle on the ground in the summer heat ?

Remi

nigel_graham(at)m-tecque.
Guest

Posted: Tue Aug 23, 2016 11:40 pm Post subject: Cooling issues XS 914 on the ground

Hi Remi,     

The honest answer is of course "no". Until I can test fly it I       won't know for sure. 

          

There are some historical reasons why the standard XS cowl       arrangement performs badly on the ground. When the XS was       developed from the Classic, the factory moved the engine up to       give them better prop clearance. This had the unintended       consequence of forcing them to use a smaller diameter spinner,       which exposed the propeller cuffs and roots. These cuffs thrash       around during ground running producing no thrust and a large       amount of turbulent air. 

          

The designers threw every known orifice at the new cowl; two       Lo-Presti's (popular at the time), two NACA vents (because all real       aeroplanes have to have NACA vents), two louvres to complete the       set and a shoe-box underneath to keep the radiator out of the cold       (I think someone added that for a bet). 

          

The problem when ground running is that all this swirling airmass       is largely passing across the mouths of these vents - not into       them. The Lo-Presti's are positioned adjacent to the blade roots       and the radiator, positioned way back in its duct, is sitting in       stagnant air. It's not until the aircraft reaches flying speed       that the apparent wind comes more from the front that air begins       to enter the vents/ducts and the cooling improves. This is one       reason why Frans Veldman's front mounted radiator arrangement is       so much more effective. High twist blades such as the Woodcomp       have been shown to give better ground-running temperatures because       they produce a much better airflow at the blade roots than many of       the flatter blade options.     

I started with the prop/spinner and worked back. I lowered the       engine to the original Classic position - but maintained the XS       forward position. This allowed me to design a much larger spinner       to completely shroud the blade cuffs and most of the blade root.       This fairs seamlessly into a new cowl that has only one duct       opening. This F16 style scoop is positioned as far down and as far       back as I can practically get to collect useful propwash and feed       the radiator and engine bay duct. For the air cooled cylinders, I       have chosen not to use conventional "high drag" vent and baffles       but have shrouded the cylinders and ducted the cooling air (like a       VW Beetle). I have managed to save so much weight by eliminating       the original landing gear and engine mounting frames that I have       enough weight budget to allow for a cooling fan within this       ducting - should one prove necessary. Only time and testing will       tell - but I've had a great time doing it!

          

Nigel

          

     On 23/08/2016 20:16, Remi Guerner       wrote:

     

      	  Quote: 	
		          	  Quote: 	
		  --> Europa-List message posted by: "Remi Guerner" <air.guerner(at)orange.fr> (air.guerner(at)orange.fr)



The dimensions will be defined by 

the aircraft speed at which the cooling should be most efficient 

(climbing, full power - probably around 80kts (41 m/s) 

Hi Nigel,

One common issue with the Europa is overheating on the ground, not in flight. It is very tempting to optimize a cowling design for low drag as you did but are you sure that such a design will allow the engine to be run indefinitely at idle on the ground in the summer heat ?

Remi





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=459805#459805

grahamsingleton(at)btinte
Guest

Posted: Wed Aug 24, 2016 12:35 am Post subject: Cooling issues XS 914 on the ground

Remi

cooling on the ground is best addressed by using exhaust extraction, this is how 



the old steam locomotives drew the air through the firebox. It's usually done on Long EZs this way, the exhaust stacks are cut off inside the cowling and draw cooling air through the fins on the cylinder head very effectively. I could run the 



160 HP Lycoming on my Long full throttle for ten minutes on a warm day before reaching CHT limits.

Graham

 

    On Wednesday, 24 August 2016, 8:41, "nigel_graham(at)m-tecque.co.uk" <nigel_graham(at)m-tecque.co.uk> wrote:



  



                     Hi Remi,

     The honest answer is of course "no". Until I can test fly it I       won't know for sure. 

     

     There are some historical reasons why the standard XS cowl       arrangement performs badly on the ground. When the XS was       developed from the Classic, the factory moved the engine up to       give them better prop clearance. This had the unintended       consequence of forcing them to use a smaller diameter spinner,       which exposed the propeller cuffs and roots. These cuffs thrash       around during ground running producing no thrust and a large       amount of turbulent air. 

     

     The designers threw every known orifice at the new cowl; two       Lo-Presti's (popular at the time), two NACA vents (because all real       aeroplanes have to have NACA vents), two louvres to complete the       set and a shoe-box underneath to keep the radiator out of the cold       (I think someone added that for a bet). 

     

     The problem when ground running is that all this swirling airmass       is largely passing across the mouths of these vents - not into       them. The Lo-Presti's are positioned adjacent to the blade roots       and the radiator, positioned way back in its duct, is sitting in       stagnant air. It's not until the aircraft reaches flying speed       that the apparent wind comes more from the front that air begins       to enter the vents/ducts and the cooling improves. This is one       reason why Frans Veldman's front mounted radiator arrangement is       so much more effective. High twist blades such as the Woodcomp       have been shown to give better ground-running temperatures because       they produce a much better airflow at the blade roots than many of       the flatter blade options.

     I started with the prop/spinner and worked back. I lowered the       engine to the original Classic position - but maintained the XS       forward position. This allowed me to design a much larger spinner       to completely shroud the blade cuffs and most of the blade root.       This fairs seamlessly into a new cowl that has only one duct       opening. This F16 style scoop is positioned as far down and as far       back as I can practically get to collect useful propwash and feed       the radiator and engine bay duct. For the air cooled cylinders, I       have chosen not to use conventional "high drag" vent and baffles       but have shrouded the cylinders and ducted the cooling air (like a       VW Beetle). I have managed to save so much weight by eliminating       the original landing gear and engine mounting frames that I have       enough weight budget to allow for a cooling fan within this       ducting - should one prove necessary. Only time and testing will       tell - but I've had a great time doing it!

     

     Nigel

     

     

     On 23/08/2016 20:16, Remi Guerner       wrote:

     

      	  Quote: 	
		          	  Quote: 	
		  --> Europa-List message posted by: "Remi Guerner" <air.guerner(at)orange.fr> (air.guerner(at)orange.fr)



The dimensions will be defined by 

the aircraft speed at which the cooling should be most efficient 

(climbing, full power - probably around 80kts (41 m/s) 

Hi Nigel,

One common issue with the Europa is overheating on the ground, not in flight. It is very tempting to optimize a cowling design for low drag as you did but are you sure that such a design will allow the engine to be run indefinitely at idle on the ground in the summer heat ?

Remi





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=459805#459805

carlp101

Joined: 07 Mar 2016
Posts: 120

Posted: Thu Aug 25, 2016 1:24 am Post subject: Re: Cooling issues XS 914 on the ground

This is all sounding very complicated.



I was having cooling issues on the ground and on extended cruise climbs. I have the 13 row oil cooler too, but the builder had it mounted with a 30 mm gap between its base and the inside cowl face. So, a lot of air was just exiting the cowl without being forced through it or the water radiator. 



I've just moved it down 30 mm so there is no gap between it and the inside of the cowl. I also made two plates that extend the sides of the aluminium cowl duct (that it's mounted to) down to the base of the oil cooler face and infront of the mounting points on either side to block off those gaps. Now, all the air that comes in through the stock rectangular cowl opening has to pass either through the water radiator or the oil radiator. There's no where else for it to go.



Testing suggests all cooling issues have been solved. On the ground I was still within temperature limits after 15+ minutes at approx 2300 rpm. In an extended cruise climb to 5400 three days ago (23+ degrees at ground level) the oil temp remained at 96 degrees C and coolent (Evans) at 75 degrees C (see attached image). During the long low-power decent back to the airfield the oil temp remained between 90 and 96, but the coolent temp went down as low as 56.



I've also fitted a thermostatic radiator valve fitted that only routes oil through the radiator when it reaches approx 83 degrees C. I'll take some pictures of the finished job and add them to this post.



It will be interesting to see how it copes this winter and if I have to partially cover either radiator. I don't think this will be necessary, but we'll see. 



All the best.

Carl

G-URMS

carlp101

Joined: 07 Mar 2016
Posts: 120

Posted: Thu Aug 25, 2016 1:31 am Post subject: Re: Cooling issues XS 914 on the ground

Hmm. I can't add a screenshot of the Skyview screen (189Kb). 



You'll have to take my word for it about the temps.

rowlandcarson(at)gmail.co
Guest

Posted: Thu Aug 25, 2016 1:45 am Post subject: Cooling issues XS 914 on the ground

On 2016-08-25, at 10:31, carlp101 <cparkinson(at)cisc-uk.com> wrote:



 	  Quote: 	
		   Hmm. I can't add a screenshot of the Skyview screen (189Kb).


	


Carl - there is a process for adding pictures but it requires human processing at the Matronics end so takes some time (and may not be available now anyway).



However, if you have a DropBox, OneDrive, BT Cloud or iCloud drive you can put stuff there and then share a link on the Matronics list.



in friendship



Rowland



| Rowland Carson          ... that's Rowland with a 'w' ...

| <rowlandcarson(at)gmail.com>            http://www.rowlandcarson.org.uk

| Skype, Twitter: rowland_carson      Facebook: Rowland Carson

cakeykev(at)gmail.com
Guest

Posted: Thu Aug 25, 2016 1:57 am Post subject: Cooling issues XS 914 on the ground

Carl



I have the same gap. Very Intrested to hear your results. Some photos would be very helpful. 



Thanks

Kevin

 	  Quote: 	
		   On 25 Aug 2016, at 10:24, carlp101 <cparkinson(at)cisc-uk.com> wrote:

 

 

 

 This is all sounding very complicated.

 

 I was having cooling issues on the ground and on extended cruise climbs. I have the 13 row oil cooler too, but the builder had it mounted with a 30 mm gap between its base and the inside cowl face. So, a lot of air was just exiting the cowl without being forced through it or the water radiator. 

 

 I've just moved it down 30 mm so there is no gap between it and the inside of the cowl. I also made two plates that extend the sides of the aluminium cowl duct (that it's mounted to) down to the base of the oil cooler face and infront of the mounting points on either side to block off those gaps. Now, all the air that comes in through the stock rectangular cowl opening has to pass either through the water radiator or the oil radiator. There's no where else for it to go.

 

 Testing suggests all cooling issues have been solved. On the ground I was still within temperature limits after 15+ minutes at approx 2300 rpm. In an extended cruise climb to 5400 three days ago (23+ degrees at ground level) the oil temp remained at 96 degrees C and coolent (Evans) at 75 degrees C (see attached image). During the long low-power decent back to the airfield the oil temp remained between 90 and 96, but the coolent temp went down as low as 56.

 

 I've also fitted a thermostatic radiator valve fitted that only routes oil through the radiator when it reaches approx 83 degrees C. I'll take some pictures of the finished job and add them to this post.

 

 It will be interesting to see how it copes this winter and if I have to partially cover either radiator. I don't think this will be necessary, but we'll see. 

 

 All the best.

 Carl

 G-URMS

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=459862#459862

JohnFrance

Joined: 17 Sep 2014
Posts: 79
Location: Grenoble France

Posted: Thu Aug 25, 2016 4:02 am Post subject: Re: Cooling issues XS 914 on the ground

Hi All,

This subject is really interesting and I imagine some of the refinements/improvements that have been found to increase cooling for 914's could be used on 912 powered aircraft without cooling problems to improve cooling efficiency and thereby reduce drag. I would very much like to see some diagrams, photos with explanatory notes when the experts reach some conclusions!

John

There are some historical reasons why the standard XS cowl       arrangement performs badly on the ground. When the XS was       developed from the Classic, the factory moved the engine up to       give them better prop clearance. This had the unintended       consequence of forcing them to use a smaller diameter spinner,       which exposed the propeller cuffs and roots. These cuffs thrash       around during ground running producing no thrust and a large       amount of turbulent air. 

          

The designers threw every known orifice at the new cowl; two       Lo-Presti's (popular at the time), two NACA vents (because all real       aeroplanes have to have NACA vents), two louvres to complete the       set and a shoe-box underneath to keep the radiator out of the cold       (I think someone added that for a bet). 

          

The problem when ground running is that all this swirling airmass       is largely passing across the mouths of these vents - not into       them. The Lo-Presti's are positioned adjacent to the blade roots       and the radiator, positioned way back in its duct, is sitting in       stagnant air. It's not until the aircraft reaches flying speed       that the apparent wind comes more from the front that air begins       to enter the vents/ducts and the cooling improves. This is one       reason why Frans Veldman's front mounted radiator arrangement is       so much more effective. High twist blades such as the Woodcomp       have been shown to give better ground-running temperatures because       they produce a much better airflow at the blade roots than many of       the flatter blade options.     

I started with the prop/spinner and worked back. I lowered the       engine to the original Classic position - but maintained the XS       forward position. This allowed me to design a much larger spinner       to completely shroud the blade cuffs and most of the blade root.

_________________
Europa mono Nr 192

dpark748(at)icloud.com
Guest

Posted: Thu Aug 25, 2016 4:15 am Post subject: Cooling issues XS 914 on the ground

Carl,

Likewise I have a 1cm gap between bottom of water radiator and bottom cowl.

I experienced heating problems on the ground in Spain on recent trip to Gibraltar.

I will be experimenting on my next trip to warmer places by closing this gap.

Have been thinking of Nev Eyres new cowl? But am put off by work involved at the moment.

Dave G-LDVO

Sent from my iPad



 	  Quote: 	
		   On 25 Aug 2016, at 10:56, Kevin Challis <cakeykev(at)gmail.com> wrote:

 

 

 

 

 Carl

 

 I have the same gap. Very Intrested to hear your results. Some photos would be very helpful. 

 

 Thanks

 Kevin

 

 

> On 25 Aug 2016, at 10:24, carlp101 <cparkinson(at)cisc-uk.com> wrote:

> 

> 

> 

> This is all sounding very complicated.

> 

> I was having cooling issues on the ground and on extended cruise climbs. I have the 13 row oil cooler too, but the builder had it mounted with a 30 mm gap between its base and the inside cowl face. So, a lot of air was just exiting the cowl without being forced through it or the water radiator. 

> 

> I've just moved it down 30 mm so there is no gap between it and the inside of the cowl. I also made two plates that extend the sides of the aluminium cowl duct (that it's mounted to) down to the base of the oil cooler face and infront of the mounting points on either side to block off those gaps. Now, all the air that comes in through the stock rectangular cowl opening has to pass either through the water radiator or the oil radiator. There's no where else for it to go.

> 

> Testing suggests all cooling issues have been solved. On the ground I was still within temperature limits after 15+ minutes at approx 2300 rpm. In an extended cruise climb to 5400 three days ago (23+ degrees at ground level) the oil temp remained at 96 degrees C and coolent (Evans) at 75 degrees C (see attached image). During the long low-power decent back to the airfield the oil temp remained between 90 and 96, but the coolent temp went down as low as 56.

> 

> I've also fitted a thermostatic radiator valve fitted that only routes oil through the radiator when it reaches approx 83 degrees C. I'll take some pictures of the finished job and add them to this post.

> 

> It will be interesting to see how it copes this winter and if I have to partially cover either radiator. I don't think this will be necessary, but we'll see. 

> 

> All the best.

> Carl

> G-URMS

> 

> 

> 

> 

> Read this topic online here:

> 

> http://forums.matronics.com/viewtopic.php?p=459862#459862

dpark748(at)icloud.com
Guest

Posted: Thu Aug 25, 2016 4:21 am Post subject: Cooling issues XS 914 on the ground

COOLING FAN FOR GROUND COOLING. Has any one experimented with a fan?



Dave Park

 	  Quote: 	
		   On 25 Aug 2016, at 13:14, david park <dpark748(at)icloud.com> wrote:

 

 

 

 Carl,

 Likewise I have a 1cm gap between bottom of water radiator and bottom cowl.

 I experienced heating problems on the ground in Spain on recent trip to Gibraltar.

 I will be experimenting on my next trip to warmer places by closing this gap.

 Have been thinking of Nev Eyres new cowl? But am put off by work involved at the moment.

 Dave G-LDVO

 

 

 Sent from my iPad

 

> On 25 Aug 2016, at 10:56, Kevin Challis <cakeykev(at)gmail.com> wrote:

> 

> 

> 

> 

> Carl

> 

> I have the same gap. Very Intrested to hear your results. Some photos would be very helpful. 

> 

> Thanks

> Kevin

> 

> 

>> On 25 Aug 2016, at 10:24, carlp101 <cparkinson(at)cisc-uk.com> wrote:

>> 

>> 

>> 

>> This is all sounding very complicated.

>> 

>> I was having cooling issues on the ground and on extended cruise climbs. I have the 13 row oil cooler too, but the builder had it mounted with a 30 mm gap between its base and the inside cowl face. So, a lot of air was just exiting the cowl without being forced through it or the water radiator. 

>> 

>> I've just moved it down 30 mm so there is no gap between it and the inside of the cowl. I also made two plates that extend the sides of the aluminium cowl duct (that it's mounted to) down to the base of the oil cooler face and infront of the mounting points on either side to block off those gaps. Now, all the air that comes in through the stock rectangular cowl opening has to pass either through the water radiator or the oil radiator. There's no where else for it to go.

>> 

>> Testing suggests all cooling issues have been solved. On the ground I was still within temperature limits after 15+ minutes at approx 2300 rpm. In an extended cruise climb to 5400 three days ago (23+ degrees at ground level) the oil temp remained at 96 degrees C and coolent (Evans) at 75 degrees C (see attached image). During the long low-power decent back to the airfield the oil temp remained between 90 and 96, but the coolent temp went down as low as 56.

>> 

>> I've also fitted a thermostatic radiator valve fitted that only routes oil through the radiator when it reaches approx 83 degrees C. I'll take some pictures of the finished job and add them to this post.

>> 

>> It will be interesting to see how it copes this winter and if I have to partially cover either radiator. I don't think this will be necessary, but we'll see. 

>> 

>> All the best.

>> Carl

>> G-URMS

>> 

>> 

>> 

>> 

>> Read this topic online here:

>> 

>> http://forums.matronics.com/viewtopic.php?p=459862#459862

gregoryf.flyboy(at)comcas
Guest

Posted: Thu Aug 25, 2016 6:23 am Post subject: Cooling issues XS 914 on the ground

I am implementing a cooling fan for ground running. No temp specs, since the

plane is in build....however, a cooling fan in similar arrangement works

great on my motorcycle, so I figured it might work well here. Its an

electric radiator fan for a quad Kart of of some sort, and covers approx.

half of the oil cooler. The oil cooler, though offset from the water cooler

(914 engine), is sealed to it in the area where they over-lap in front of

the fan to promote airflow through both radiators (sucking air through the

oil radiator will also do the same with the water radiaor...lots of work

here to create tight-fitting air dams). Having the two radiators tight with

each other will hopefully cut down on warm-up time during the winter as

well. The fan is lightweight, cheap, and only requires a wire run and

switch. Once verified to work, it will be made to be automatic on/off. For

extreme cooling situations in flight with the airflow pushing and the fans

pulling, the extra leverage 'seems' a no-brainer. I figure it won't windmill

much if at all in the airflow while off, due to the resistance to the air by

the radiators mounted in front of it. This arrangement would be much easier

to implement with the radiators in-line with each other, but the offset is

known to work well, and the decision had already been made.  More data will

follow at some point..

Greg Fuchs 

914 TRI



--

dpark748(at)icloud.com
Guest

Posted: Thu Aug 25, 2016 6:56 am Post subject: Cooling issues XS 914 on the ground

Can you give fan specs and where available!



Dave Park

[quote] On 25 Aug 2016, at 15:22, Greg Fuchs <gregoryf.flyboy(at)comcast.net> wrote:

 

 

 

 I am implementing a cooling fan for ground running. No temp specs, since the

 plane is in build....however, a cooling fan in similar arrangement works

 great on my motorcycle, so I figured it might work well here. Its an

 electric radiator fan for a quad Kart of of some sort, and covers approx.

 half of the oil cooler. The oil cooler, though offset from the water cooler

 (914 engine), is sealed to it in the area where they over-lap in front of

 the fan to promote airflow through both radiators (sucking air through the

 oil radiator will also do the same with the water radiaor...lots of work

 here to create tight-fitting air dams). Having the two radiators tight with

 each other will hopefully cut down on warm-up time during the winter as

 well. The fan is lightweight, cheap, and only requires a wire run and

 switch. Once verified to work, it will be made to be automatic on/off. For

 extreme cooling situations in flight with the airflow pushing and the fans

 pulling, the extra leverage 'seems' a no-brainer. I figure it won't windmill

 much if at all in the airflow while off, due to the resistance to the air by

 the radiators mounted in front of it. This arrangement would be much easier

 to implement with the radiators in-line with each other, but the offset is

 known to work well, and the decision had already been made.  More data will

 follow at some point..

 Greg Fuchs 

 914 TRI

 

 --

Display posts from previous:

	Matronics Email Lists Forum Index -> Europa-List	All times are GMT - 8 Hours Goto page 1, 2 Next
Page 1 of 2

Jump to:

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