---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Wed 01/28/09: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:37 PM - 914 w/intercooler induction air heating (pasj66) 2. 02:06 PM - Re: 914 w/intercooler induction air heating (Gilles Thesee) 3. 03:17 PM - rotax 912 over-run experience (ndibiase) 4. 03:30 PM - Re: 914 w/intercooler induction air heating (rparigor@suffolk.lib.ny.us) 5. 08:42 PM - Re: 914 w/intercooler induction air heating (Evan Gardiner) 6. 11:27 PM - Re: 914 w/intercooler induction air heating (pasj66) ________________________________ Message 1 _____________________________________ Time: 12:37:11 PM PST US Subject: RotaxEngines-List: 914 w/intercooler induction air heating From: "pasj66" Hi all, I am searching for some info on the temperature difference between airbox temperature and ambient during flight. JAR 23.1093 states if the temperature rise is more than 56 deg C when ambient temperature is -1 deg C at 60 % power there is no need for carb heating. In JAR-VLA 1093 the temperature rise should be 38 deg C with the same conditions. Has anyone with a 914 w/intercooler done some flight tests? Installing carb heating is a bit of a hassle so I hope anyone have done these tests to find out whether it is necessary. If anyone can share their findings that would be most helpful. Best regards Patrik (MCR R100 914 w/intercooler 85 % finished) -------- MCR R100, R914UL3 W/IC Read this topic online here: http://forums.matronics.com/viewtopic.php?p=227384#227384 ________________________________ Message 2 _____________________________________ Time: 02:06:43 PM PST US From: Gilles Thesee Subject: Re: RotaxEngines-List: 914 w/intercooler induction air heating Patrick and all, > I am searching for some info on the temperature difference between airbox temperature and ambient during flight. JAR 23.1093 states if the temperature rise is more than 56 deg C when ambient temperature is -1 deg C at 60 % power there is no need for carb heating. In JAR-VLA 1093 the temperature rise should be 38 deg C with the same conditions. Has anyone with a 914 w/intercooler done some flight tests? Installing carb heating is a bit of a hassle so Remember those rules have been written by people used to Lyco/Conti aircooled engines, with hot air as the sole means of avoiding carb ice. We are flying an MCR 4s with an intercooled 914. Due to our engine installation peculiarities, our carb temperatures are within the 40-50C range in flight. Whatever the air temperature, remember ice cannot build up on warm metal. But it all depends on your particular engine installation. With a proper airbox around the air filter, it is no big deal to devise a warm air door into the engine compartment. FWIW, Best regards, -- Gilles http://contrails.free.fr ________________________________ Message 3 _____________________________________ Time: 03:17:54 PM PST US Subject: RotaxEngines-List: rotax 912 over-run experience From: "ndibiase" Someone as experience with over run 912 ULS engine and (bad) consequence ? In fact after renting to a friend of mine my loved airplane (with a variable pitch propeller with stops too light loaded - so possible over run ) i experience a power loss. Spinning by hand my prop seems that one cylinder has less compression than the other (I'll ask my local rotax representative do a compression check and i suspect something happened in valves seats or timing rods ). But in my experience it is almost impossible to damage a rotax 912 with overrun. Rotax officials said me that they have seen 6800 rpm for tens of seconds with no damage... I know that rotax says that over 6100 rpm for ......you must check all the engine but often reality is less tragic! any stories or knowledge ? thanks Nicola di Biase Read this topic online here: http://forums.matronics.com/viewtopic.php?p=227408#227408 ________________________________ Message 4 _____________________________________ Time: 03:30:35 PM PST US Subject: Re: RotaxEngines-List: 914 w/intercooler induction air heating From: rparigor@suffolk.lib.ny.us Hi Gilles "our carb temperatures are within the 40-50C range in flight. Whatever the air temperature, remember ice cannot build up on warm metal." Curiosity question, what is your carb temperature when you pull power to a low power settingor idle and you let the wind turn propellor (turbo not doing much in the way of rammin and jammin / hence warming and the intercooler is bringing down any rise in temp caused by turbo closer to ambient)? Have you ever gotten carb ice? If yes did making some BTUs cure it? Thx. Ron Parigoris ________________________________ Message 5 _____________________________________ Time: 08:42:33 PM PST US From: "Evan Gardiner" Subject: RotaxEngines-List: Re: 914 w/intercooler induction air heating Hi guys, Apparently a 914 powered MCR generates more ambient heat in the engine cowl ing than the 912 S powered MCR ULC that I have. I have attached a temp. pro be to a carburator body and it never rises above 25 degrees C during what a ppears to be carb ice conditions. If the temp. ever starts to fall below 19 degrees, (displayed on the panel) I know it is time to activate carb heat. I leave it on until the temp. rises above 23 degrees again. As you note, i ce will not stick on warm metal. Here in New Zealand we sometimes have quite pronounced carb ice conditions. After 3 such forced landing events without a carb heat facility I fitted a flap to close off the outside ram air just to have some control over the s ituation. It is now quite interesting watching the correlation between the rising temp in the airbox, which I also moniter, and the temp of the carb b ody. Takes a few minutes sometimes - but it is less stressful than looking for somewhere to land with no noise up front! Regards, Evan Gardiner -- We are a community of 5.9 million users fighting spam. The Professional version does not have this message ________________________________ Message 6 _____________________________________ Time: 11:27:53 PM PST US Subject: RotaxEngines-List: Re: 914 w/intercooler induction air heating From: "pasj66" Hi Gilles, I have visited your web site quite often the last year during the assembly of our MCR. Very helpful and informative. Regarding carb heat the JAR specification has to be met somehow in order to get a type certificate, and the fact that Dynaero does not offer a carb heat option to their factory built 914 installations the pre certification flight tests must have shown that it was not needed. I am waiting for a mail from dynaero in this matter. In addition it is interesting to hear other peoples experiences. Best regards Patrik -------- MCR R100, R914UL3 W/IC Read this topic online here: http://forums.matronics.com/viewtopic.php?p=227456#227456 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rotaxengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RotaxEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rotaxengines-list Browse Digests http://www.matronics.com/digest/rotaxengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.