---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Mon 06/04/07: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:04 AM - Re: Re: 582 cooling circuit pressure valve (Noel Loveys) 2. 07:35 AM - Re: 582 cooling circuit pressure valve (Roger Lee) 3. 07:36 AM - Re: 912UL not Starting (Roger Lee) 4. 10:52 AM - Re: Re: 582 cooling circuit pressure valve () 5. 02:06 PM - Re: 582 cooling circuit pressure valve (Roger Lee) ________________________________ Message 1 _____________________________________ Time: 05:04:56 AM PST US From: "Noel Loveys" Subject: Re: RotaxEngines-List: Re: 582 cooling circuit pressure valve Don't forget the higher up you go the lower the boiling point of water, or any liquid for that matter. That is why you can't get a boiled egg in the highest mountains...Don't even think of making a "good" cup of tea!! Without the pressure cap you will find the same thing that happens without it in a car. The engine will work pretty well until enough of the fluid boils off then the temperature will sky rocket! When I first got my 'Fox with the 582 the builder had plumbed it with the surge tank Teed into the return line to the engine. This of course vented the the cooling system to ambient pressure. Needless to say flights were very short before the coolant needed replenishment and you don't do that on a warm engine. The cooling system was re-plumbed with the surge tank on the low pressure side of the filler cap and now it works real well! Noel Loveys, RPP, AME intern Campbellton, Newfoundland, Canada Kitfox Mod III-A, 582, B box, Ivo IFA Aerocet 1100s noelloveys@yahoo.ca Do not archive > -----Original Message----- > From: owner-rotaxengines-list-server@matronics.com > [mailto:owner-rotaxengines-list-server@matronics.com] On > Behalf Of RotaxEngines-List Digest Server > Sent: Friday, June 01, 2007 4:27 AM > To: RotaxEngines-List Digest List > Subject: RotaxEngines-List Digest: 3 Msgs - 05/31/07 > > > * > > ================================================= > Online Versions of Today's List Digest Archive > ================================================= > > Today's complete RotaxEngines-List Digest can also be found > in either of the > two Web Links listed below. The .html file includes the > Digest formatted > in HTML for viewing with a web browser and features > Hyperlinked Indexes > and Message Navigation. The .txt file includes the plain > ASCII version > of the RotaxEngines-List Digest and can be viewed with a > generic text editor > such as Notepad or with a web browser. > > HTML Version: > > > http://www.matronics.com/digest/digestview.php?Style=82701 &Vie > w=html&Chapter 07-05-31&Archive=RotaxEngines > > Text Version: > > > http://www.matronics.com/digest/digestview.php?Style=82701 &Vie > w=txt&Chapter 07-05-31&Archive=RotaxEngines > > > =============================================== > EMail Version of Today's List Digest Archive > =============================================== > > > ---------------------------------------------------------- > RotaxEngines-List Digest Archive > --- > Total Messages Posted Thu 05/31/07: 3 > ---------------------------------------------------------- > > > Today's Message Index: > ---------------------- > > 1. 08:01 AM - Re: 582 cooling circuit pressure valve > (Guy Buchanan) > 2. 01:48 PM - Re: 582 cooling circuit pressure valve (Renaud) > 3. 09:31 PM - Re: Re: 582 cooling circuit pressure valve > (Guy Buchanan) > > > > ________________________________ Message 1 > _____________________________________ > > > Time: 08:01:22 AM PST US > From: Guy Buchanan > Subject: Re: RotaxEngines-List: 582 cooling circuit pressure valve > > > At 11:29 PM 5/30/2007, you wrote: > >Does one of you know the reason for pressurizing the cooling > >circuit: avoiding cavitation in the pump, increasing the boiling > >temperature of water, etc? Is there any risk of damaging the water > >pump when running unpressurized? > > Renaud, > You've got it right on both counts, though I seriously doubt > you can damage the water pump running unpressurized. The reason the > temperature usually drops below 140F is that the thermostat opens. I > usually see a 5-10F drop when that happens during warm-up. Be > careful, if your temperature is dropping rapidly from high to low due > to the thermostat opening you could experience "cold seizure", or > otherwise damage your pistons. If you're see a noticeable drop it may > mean your thermostat is not opening until a higher temperature and > then you're "quenching" the engine; not good. > I would look for the drop at 140 every time you warm up. If > you get a consistent rise past 150 I'd say your thermostat never > opened and should be replaced. > > > Guy Buchanan > San Diego, CA > K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar. > > > ________________________________ Message 2 > _____________________________________ > > > Time: 01:48:05 PM PST US > Subject: RotaxEngines-List: Re: 582 cooling circuit pressure valve > From: "Renaud" > > > Guy, > Thanks for your quick reply! I have no thermostat! > I tried it today after manoeuvering the cabin radiator > insulating valve and everything > is fine now. No way to reproduce the problem... Maybe this > valve was just > stightly open and some cold water from the cabin radiator was > pumped only > with full RPM?! > > However, I still don't understand the reason for having (or > not having) a pressure > valve at the expansion tank plug. > > Based on all I read about "cold seizing", I will definitely > install a thermostat. > > Anyway, thanks again for your reply. Happy flying with Kitfox! > > -------- > Renaud > > KitFox IV - 1200. Rotax 582. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=115823#115823 > > > ________________________________ Message 3 > _____________________________________ > > > Time: 09:31:31 PM PST US > From: Guy Buchanan > Subject: Re: RotaxEngines-List: Re: 582 cooling circuit pressure valve > > > At 01:47 PM 5/31/2007, you wrote: > >Maybe this valve was just stightly open and some cold water from the > >cabin radiator was pumped only with full RPM?! > > Glad to hear it worked out. > > >However, I still don't understand the reason for having (or not > >having) a pressure valve at the expansion tank plug. > > I guess you're talking about a pressure cap on the expansion tank. > The boiling point of the fluid increases with pressure. With a 15 psi > cap, (standard,) the boiling point of pure water increases 120F. I > don't know what the glycol mixture increases, but it might be the > same. The increased vapor pressure will also inhibit cavitation. Now > you might think that since we never go over 180F, who needs the > pressure? The answer is that you can get local hot spots in the water > jacket. If these boil the local heat transfer coefficient drops > dramatically, (vapor has a much lower heat transfer coefficient than > fluid,) and the hot spot can turn into a hole. (This was supposedly a > problem with the 912 and the reason they went to the Evans coolant.) > > >Based on all I read about "cold seizing", I will definitely install > >a thermostat. > No, No! You've got it backwards! Cold seizure generally happens with > a thermostat! If you don't have a thermostat it's harder to get "cold > seizure" but you can run the engine too cold, with the concomitant > poor performance. > > > Guy Buchanan > San Diego, CA > K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar. > > > > > > > > > > ________________________________ Message 2 _____________________________________ Time: 07:35:56 AM PST US Subject: RotaxEngines-List: Re: 582 cooling circuit pressure valve From: "Roger Lee" Hi Renaud, If you want a little higher temp and a more stable temp. Replace your coolant with some Evans NPG+. They claim you can run a no pressure cap, but Rotax recomends you still use the pressure cap. Evans is a waterless coolant that a lot of Rotax 912 owners use. Evans is used in lots of other applications like other planes, cars, motorcycles, ect... I have used it for 5 years and I'm happy with it. No water, no corrosion. It will raise the boiling point of your coolant from approx. 275F to 375F before it boils. It won't hurt anything. Try it and if you don't like it then go back to the 50/50 coolant. It's just something different. Some people like it and others have mixed opinions. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=116358#116358 ________________________________ Message 3 _____________________________________ Time: 07:36:04 AM PST US Subject: RotaxEngines-List: Re: 912UL not Starting From: "Roger Lee" Did you find your problem? -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=116359#116359 ________________________________ Message 4 _____________________________________ Time: 10:52:39 AM PST US Subject: Re: RotaxEngines-List: Re: 582 cooling circuit pressure valve From: "Evans NPG+. They claim you can run a no pressure cap" This may be stated by Evans, but they expect you have the pressure cap on the suction side of pump. I am not familiar with 582 system, but a 914 has cap on high pressure side. On 914 will be running .9bar Ron P. ________________________________ Message 5 _____________________________________ Time: 02:06:38 PM PST US Subject: RotaxEngines-List: Re: 582 cooling circuit pressure valve From: "Roger Lee" Rotax still wants a pressure cap. 13 psi or .9 bar works well. -------- Roger Lee Tucson, Az. 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