Matronics Email Lists :: View topic - Coolant flammability tests

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

Coolant flammability tests

Matronics Email Lists Forum Index -> RotaxEngines-List

View previous topic :: View next topic

Author Message

Gilles.Thesee(at)ac-greno
Guest

Posted: Sat May 05, 2007 12:06 pm Post subject: Coolant flammability tests

Hi all,



Rotax drivers may be interested in the flammability tests conducted by 

Europa builders Ron Parigoris and Wayne Gutschow on engine coolants and 

fluids.



http://contrails.free.fr/engine_burn_baby_burn_en.php



Regards,

Gilles Thesee

Grenoble, France

http://contrails.free.fr

- The Matronics RotaxEngines-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?RotaxEngines-List

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Sat May 05, 2007 2:23 pm Post subject: Re: Coolant flammability tests

Hi Gilles,



How are you?

If I remember right the big issue was Evans coolant? 

We discussed this a while back. Bottom line is how high the temps have to get to cause it to burn and if it is in any type of fire it is a very limited quanity. Why worry if there is a fire as you have fuel and oil, all the rubber and plastic in the engine that is far worse and burns at lower temps. When you really compare Evans to the other things in the engine compartment that burn it's just at the bottom of the list and you have much bigger problems to worry about if there is a fire. Some things look good by themselves or on paper, but when you include the whole picture it's not worth worrying about. I'm a Fireman and HazMat Tech. by trade for the last 28 years. I have been to, God only knows how many car fires and I have been to aircraft fires. Knowing what is in the general area to burn and at what temps. puts Evans Coolant at the bottom of my list. The only thing hot enoug in our engine is the exhaust manifold. They are worried about Evans, I think they should be more worried about fuel. It will lite off at a much lower temp. and it will burn up to 2000F. All the rubber parts and some plastic will lite off if it falls against the exhaust manifold. There is a lot more of this stuff to start a fire. There is very little coolant in your engine. Tell them to test all the other components in the engine compartment. You may not want to fly then. Human nature usually only carries things out to a certain point and then we quit looking past that point. Follow it past the Evans to everything else and then this single point they make isn't as big. The bottom line is any engine fire reguardless of the cause can be deadly. Good maint. scheduling and checking your equipment can go a long way to saving your hide. Don't be cheap is what I tell people when it coes to parts and maint. . The part may look good on the outside, but it's waiting to bite you on the backside if you neglect it or don't replace it.



I don't mean to upset anyone in any way, sound like a broken record or a lecturer, but if all I had to worry about was Evans then my life is simple. I have used Evans now for 4 years and have been happy with its performance.

- The Matronics RotaxEngines-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?RotaxEngines-List

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

rampil

Joined: 04 May 2007
Posts: 870

Posted: Sat May 05, 2007 5:13 pm Post subject: Re: Coolant flammability tests

Hi Roger



Are you using Evans out there in Tucson because the ambient temp

on the tarmac is already above the boiling point of water-based coolant?



(



At least it seemed that way to me the last time I spent a day at Davis-

Motham and at Pima

- The Matronics RotaxEngines-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?RotaxEngines-List

_________________
Ira N224XS

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Sat May 05, 2007 5:50 pm Post subject: Re: Coolant flammability tests

Hi Rampil,



No actually I use it because the regualr 50/50 can get into hot spots or poor circulation areas within the heads and get too hot and vaporize. This causes a vapor space and causes overheating in or around the head. This softens the metal and causes leaks and warpping. Regular 50/50 boils around 275F or so, and Evans boils at 375F. This also helps the engine from puking coolant all over the ground when you are stuck on the tarmac for a while idling or long taxi's and poor air movement for cooling. The articles written by several authors say you should use Evans unless you are having an engine over heating problem. Evans can make you run about 30F warmer, but if it doesn't over heat, so what. If I was constantly over heating I might drop back to 50/50. Evans will not leave deposits in the system or corrode parts because it doesn't have any water. You should use it unless you are always over heating to drop the temps. 30F, but you are a head of the game if you do not over heat and you use Evans.

- The Matronics RotaxEngines-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?RotaxEngines-List

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

Gilles.Thesee(at)ac-greno
Guest

Posted: Sat May 05, 2007 11:50 pm Post subject: Coolant flammability tests

Roger Lee a écrit :

 	  Quote: 	
		   



 Hi Rampil,



 No actually I use it because the regualr 50/50 can get into hot spots or poor circulation areas within the heads and get too hot and vaporize. This causes a vapor space and causes overheating in or around the head. This softens the metal and causes leaks and warpping. Regular 50/50 boils around 275F or so, and Evans boils at 375F. This also helps the engine from puking coolant all over the ground when you are stuck on the tarmac for a while idling or long taxi's and poor air movement for cooling. The articles written by several authors say you should use Evans unless you are having an engine over heating problem. Evans can make you run about 30F warmer, but if it doesn't over heat, so what. If I was constantly over heating I might drop back to 50/50. Evans will not leave deposits in the system or corrode parts because it doesn't have any water. You should use it unless you are always over heating to drop the temps. 30F, but you are a head of the game if you do not over heat !

  and you use Evans.



   


	


Roger and all,



You are right, as long as your are not overheating, using pure propylene 

glycol like Evan's NPG+  won't harm your engine.

What is surprisingly not well known by magazine editors, is that 

nucleate boiling is a normal phenomenon in any liquid cooled piston 

engine. It helps reject tremendous amounts of heat from  the engine.

Phase change from liquid to vapor absorbs many times more heat than just 

raising the coolant temperature another degree, and helps convection.

This was clearly established by NACA researchers on liquid cooling 

during the '40s.



See Contrails

http://contrails.free.fr/engine_liquide_refroid.php (only in French at 

the moment)

Scroll down to the NACA reports.



Also some gneral info at :

http://www.tpub.com/content/doe/h1012v2/css/h1012v2_62.htm



Please note that we are speaking of nucleate boiling, and not of  the 

"boiling crisis", which is the transition from nucleate to "film 

boiling". It is film boiling which tends to isolate the hot walls from 

the coolant. It can happen

So the "no boil" argument put forth by propylene glycol sellers is not 

so valid.

Also it is not water that leaves deposits, but wrongly formulated 

coolants with no inhibitors.

Even the Evans (no water) contains a corrosion inhibitor.



Best regards,

Gilles

http://contrails.free.fr

- The Matronics RotaxEngines-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?RotaxEngines-List

Gilles.Thesee(at)ac-greno
Guest

Posted: Sat May 05, 2007 11:55 pm Post subject: Coolant flammability tests

Roger Lee a écrit :

 	  Quote: 	
		   How are you?

 If I remember right the big issue was Evans coolant? 

 We discussed this a while back. Bottom line is how high the temps have to get to cause it to burn and if it is in any type of fire it is a very limited quanity. Why worry if there is a fire as you have fuel and oil, all the rubber and plastic in the engine that is far worse and burns at lower temps. When you really compare Evans to the other things in the engine compartment that burn it's just at the bottom of the list and you have much bigger problems to worry about if there is a fire. Some things look good by themselves or on paper, but when you include the whole picture it's not worth worrying about. I'm a Fireman and HazMat Tech. by trade for the last 28 years. I have been to, God only knows how many car fires and I have been to aircraft fires. Knowing what is in the general area to burn and at what temps. puts Evans Coolant at the bottom of my list. The only thing hot enoug in our engine is the exhaust manifold. They are worried about Evans, I think they should be more !

  worried about fuel. It will lite off at a much lower temp. and it will burn up to 2000F. All the rubber parts and some plastic will lite off if it falls against the exhaust manifold. There is a lot more of this stuff to start a fire. There is very little coolant in your engine. Tell them to test all the other components in the engine compartment. You may not want to fly then. Human nature usually only carries things out to a certain point and then we quit looking past that point. Follow it past the Evans to everything else and then this single point they make isn't as big. The bottom line is any engine fire reguardless of the cause can be deadly. Good maint. scheduling and checking your equipment can go a long way to saving your hide. Don't be cheap is what I tell people when it coes to parts and maint. . The part may look good on the outside, but it's waiting to bite you on the backside if you neglect it or don't replace it.

   


	


Hi Roger,



What is interesting in Ron's report is, he made experiments.

Of course many engine fluids burn, especially oil and fuel. But Ron and 

Wayne's findings help us sorting out the coolant flammability issue by 

providing hard facts.



Best regards,

Gilles

http://contrails.free.fr

- The Matronics RotaxEngines-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?RotaxEngines-List

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Sun May 06, 2007 6:13 am Post subject: Re: Coolant flammability tests

Hi Gilles,



I agree that when a liquid changes phase from the let's say water or coolant to vapor it has absorbed more heat, momentarily. The problem with that is we can't circulate vapor and it can and does leave dead spots in the head. Now we loose the cooling in that spot. Rotax heads are cooled by the coolant and the cylinders are air cooled. Get a dead vapor spot in the head and the temp. probe may or may not pick up the heat problem because the spot is isolated and we don't usually monitor all 4 head temps. Rotax has pictures to demonstrate this problem. Engine MFG's. try real hard not to have vapor areas in their engines.

- The Matronics RotaxEngines-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?RotaxEngines-List

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

Gilles.Thesee(at)ac-greno
Guest

Posted: Sun May 06, 2007 11:32 am Post subject: Coolant flammability tests

Hi Roger,



Thank you for responding.

 	  Quote: 	
		   The problem with that is we can't circulate vapor and it can and does leave dead spots in the head.


	


Nucleate ebullition does help liquid cooling and is present in the 

majority of internal combustion engines when at working temperatures.

It is this phenomenon which provides the near constant temps.

Tiny bubbles are created at every hot spot in the engine, cool the area, 

then are entrained in the general coolant flow. As soon as they leave 

the hot wall, they collapse, due to the coolant temp being lower than 

the overheating spots.

When the coolant flow slows, the proportion of nucleate ebullition 

rises, helping cooling in adverse conditions.

 	  Quote: 	
		    Now we loose the cooling in that spot.


	


If and when the heat flow through the engine wall exceeds the cooling 

capacity of nucleate ebullition, then yes "film cooling" develops and 

the heat transfer is impaired.



 	  Quote: 	
		    Engine MFG's. try real hard not to have vapor areas in their engines.

   

Of course I'm not talking of boiling off the coolant, but things are 
	


more subtle than commonly perceived at first glance. A certain amount of 

ebullition really helps keeping temperatures under control.

The provided links to the NACA studies on engine liquid cooling, and on 

thermal dissipation will shed some light on the phenomenon (and in much 

better English 

Evans also gives a clear explanation on nucleate ebullition.



Best regards,

Gilles

http://contrails.free.fr

- The Matronics RotaxEngines-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?RotaxEngines-List

Display posts from previous:

	Matronics Email Lists Forum Index -> RotaxEngines-List	All times are GMT - 8 Hours
Page 1 of 1

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