---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Thu 11/15/12: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:15 AM - Re: Rotax 912 Preheating (FLYaDIVE) 2. 05:14 AM - Re: Rotax 912 Preheating (dashwood) 3. 05:47 AM - Re: Re: Rotax 912 Preheating (FLYaDIVE) 4. 08:43 AM - Re: Re: Rotax 912 Preheating (Gerry Visel) 5. 10:06 AM - Re: Re: Rotax 912 Preheating (FLYaDIVE) 6. 10:34 AM - Re: Re: Rotax 912 Preheating (Gerry Visel) 7. 04:01 PM - Re: Re: Rotax 912 Preheating (rayj) ________________________________ Message 1 _____________________________________ Time: 04:15:33 AM PST US Subject: Re: RotaxEngines-List: Rotax 912 Preheating From: FLYaDIVE Hi Raymond: The theory is this: There is water in the oil. There is water condensed on the metal parts of the engine. When the water freezes it creates ice crystals - Some of these ice crystals are between parts such as connecting rods and journals of the crank shaft. When water freezes it expands - This puts uneven pressure on the connected parts. Journals, guides and bearings. Squeezing out the oil. If there is Water in those areas there is NO oil in those areas - So there is the possibility of metal to metal ware. This is the THEORY - It has some merit. But, Adam Ant has not gotten inside the engine and taken pictures so I don't know 1,000%. I do KNOW this: A pre-heated engine starts easier than a non-pre-heated engine. A plane that I fly, an RV6, won't even think of starting at temps near freezing. Which brings up a second theory: Most aircraft engines have very sloppy tolerances between mating parts. If you have a better than average engine with close tolerances and there are dissimilar metals in contact (Steel and Aluminum) each metal has a different coefficient of expansion. Aluminum expands more than steel. You could put higher pressures and uneven pressure on mating parts. Chose which ever theory you like - But, Pre-Heat. Your engine will like you for it. And may even last longer. Barry On Wed, Nov 14, 2012 at 11:29 PM, rayj wrote: > Please explain what the freezing point of water has to do with when to > preheat an engine that is cooled with a combination of antifreeze and air. > > Raymond Julian > Kettle River, MN. > > "And you know that I could have me a million more friends, > and all I'd have to lose is my point of view." - John Prine > > On 11/14/2012 09:58 PM, FLYaDIVE wrote: > > Damien: > > Pre-heating is a function of FREEZING which starts at either 0 C or 32 > F. It is NOT a function of Manufacture. So unless ROTAX uses a different > freezing point - - - Kelvin maybe - - - Start Pre-heating at the freezing > point. > Pre-heating is also helpful when it comes to PLASTICS. Many a knob and > gear have become loose or broken when the temps drop. Personally - I begin > to function slower as the temps get lower, so it is just as important to me > to be Pre-Heated. > > Barry > > On Wed, Nov 14, 2012 at 10:57 AM, Damien wrote: > >> Hello Group. >> There is an article in this month's EAA Bits and Pieces for Canada about >> preheating engines. It mentions the temps that trigger preheating for >> Continentals and Lycomings. I have not been able to find sugesstions for >> the Rotax 912. Does anyone know what the temperature would have to dip to >> require a preheat for the Rotax 912 ? Thanks. >> Regards, >> Damien Graham >> N48TK >> >> * >> >> _blank">www.aeroelectric.com >> .com" target="_blank">www.buildersbooks.com >> ="_blank">www.homebuilthelp.com >> _blank">http://www.matronics.com/contribution >> ist" target="_blank">http://www.matronics.com/Navigator?RotaxEngines-List >> tp://forums.matronics.com >> * >> >> > * > > * > > > * > > * > > ________________________________ Message 2 _____________________________________ Time: 05:14:34 AM PST US Subject: RotaxEngines-List: Re: Rotax 912 Preheating From: "dashwood" some are getting close "dissimilar metals in contact (Steel and Aluminum) each metal has a differentcoefficientofexpansion. Aluminumexpandsmore than steel. You could put higher pressures and uneven pressure on mating parts. " this is one of the main reasons but another is the oil... oil only.... there is no water in an engine that runs often. one that sits for long perionds may... may have some condensation filter in..... but its the oil... shelll sport 4 is like cement , or molassis , or thick glue.. at lower temps....it cant be pumped or moved through a cold engine... try it ... a lot of metal clankin goin on till the oil is warmed and if you dont pre warm it ... its the friction from metal on metal that has to do the warmin up... . i have 100wat bulb on under the engine cowl from now till spring... and a bear blanket wrapped on the outside... live near detoit / toronto. any time the temp is below35/37 degrees i change oil to 0w40amsoil syn. and use the light....at temps below 20deg F i also us a propane heater for 30min . no one has to pre heat... but everyone should..alway... these engines are a big investment... try leaving $16000.00 at the curb and see if it needs warming in at night... it will just leave mysteriously... your engine is the same .. it will just leave you... one little part at a time... . all / any oil is the same to varying degrees... some are using 50w .. put that in the fridge over night and do a fluid test... it no longer is fluid...its rock hard.. 0wXX will be better but still is not great.. -------- Ross Aalexander: CH701 driver 912ul 589tt It only takes two things to fly, airspeed and money Read this topic online here: http://forums.matronics.com/viewtopic.php?p=387950#387950 ________________________________ Message 3 _____________________________________ Time: 05:47:24 AM PST US Subject: Re: RotaxEngines-List: Re: Rotax 912 Preheating From: FLYaDIVE Hi Ross: There is always water in oil. Of course you reduce the quantity by flying often. An easy way to prove this to yourself is: After a flight - Open up your Oil Cap. What do you see coming out? A white vapor. That white vapor is water. Now, take a smooth sheet of aluminum and hold it in the vapor. What do you see? Water condensing on the aluminum. Part of the normal COMBUSTION process is water - http://en.wikipedia.org/wiki/Combustion And as combustion gases get past the rings of the pistons they get into the crank area of the engine. OIL is in the crank area of the engine and the oil absorbs the water. Another way of proving this is: Do this out side. Take a quart of NEW oil. Put it in a glass jar. Weigh the oil & jar - ACCURATELY - Gram Scale Put another Larger Glass jar over the first. Set up the second glass jar so it is raised an inch with 5 blocks around the edge. It has to breathe - Just like an engine. Let it sit OUTSIDE for a couple of months - [Requirement - You can't live in the Sara Desert] Weigh the oil & glass jar... Guess what? It became heaver - WATER was absorbed into the oil. Another proof: In the cold weather - DURING PRE-FLIGHT - Slowly and carefully pull out your dipstick (NO! Not that one!!!) - Look at the clear droplets that are on it. That is water. If it is on your dipstick, it is in your engine. If it is in your engine, it is in your oil. YES running an engine does reduce the amount of water but not totally. Hope this explains things. Barry On Thu, Nov 15, 2012 at 8:14 AM, dashwood wrote: > dashwoodlock@hotmail.com> > > some are getting close "dissimilar metals in contact (Steel and > Aluminum) each metal has a different=EF=BDcoefficient=EF=BDof=EF =BDexpansion.=EF=BD > Aluminum=EF=BDexpands=EF=BDmore than steel. =EF=BDYou could put higher pressures and > uneven pressure on mating parts. " > this is one of the main reasons but another is the oil... oil only.... > there is no water in an engine that runs often. one that sits for long > perionds may... may have some condensation filter in..... but its the > oil... shelll sport 4 is like cement , or molassis , or thick glue.. a t > lower temps....it cant be pumped or moved through a cold engine... try it > ... a lot of metal clankin goin on till the oil is warmed and if you don t > pre warm it ... its the friction from metal on metal that has to do the > warmin up... . i have 100wat bulb on under the engine cowl from now till > spring... and a bear blanket wrapped on the outside... live near detoit / > toronto. any time the temp is below35/37 degrees i change oil to > 0w40amsoil syn. and use the light....at temps below 20deg F i also us a > propane heater for 30min . > no one has to pre heat... but everyone should..alway... these engines > are a big investment... try leaving $16000.00 at the curb and see if it > needs warming in at night... it will just leave mysteriously... your > engine is the same .. it will just leave you... one little part at a > time... . all / any oil is the same to varying degrees... some are using > 50w .. put that in the fridge over night and do a fluid test... it no > longer is fluid...its rock hard.. 0wXX will be better but still is not > great.. > > -------- > Ross Aalexander: CH701 driver 912ul 589tt > It only takes two things to fly, airspeed and money > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=387950#387950 > > =========== =========== =========== =========== > > ________________________________ Message 4 _____________________________________ Time: 08:43:11 AM PST US Subject: Re: RotaxEngines-List: Re: Rotax 912 Preheating From: Gerry Visel Barry, Do you preheat your car? With it's big oil sump, you'll see lots more water there. Somehow they last for many hundreds of thousands of miles without (most people) preheating. (If you drive a diesel, this does not apply due to the higher compression ratios. I preheated my old Benz, even with its glow plugs, to help it turn over easier.) However, water in engines all gets boiled off during operation, so the only water you will see is from what might have condensed inside since last shutdown. I think you are worried too much about its effects. If it was a serious issue, you sure would have at least seen a procedure for how to do it in the engine owner's manual. That said, I sure agree that it is sure a whole lot easier to start a pre-heated engine when it is really cold outside! Gerry On Thu, Nov 15, 2012 at 7:46 AM, FLYaDIVE wrote: > Hi Ross: > > There is always water in oil. Of course you reduce the quantity by > flying often. > An easy way to prove this to yourself is: > After a flight - Open up your Oil Cap. What do you see coming out? A > white vapor. That white vapor is water. Now, take a smooth sheet of > aluminum and hold it in the vapor. What do you see? Water condensing on > the aluminum. > > Part of the normal COMBUSTION process is water - > ________________________________ Message 5 _____________________________________ Time: 10:06:24 AM PST US Subject: Re: RotaxEngines-List: Re: Rotax 912 Preheating From: FLYaDIVE Gerry: You did not spend much time thinking through your email. 1 - You did not ask where I live -- - I could live in Florida and never require pre-heating. I could live in Alaska or North Dakota and have to pre-heat all winter long. Did you know that in extreme cold areas such as Alaska and North Dakota, if the plane is going to sit for a few days and then be flown, they remove the oil and bring it in a heated area. 2 - The size of the sump (not a sump but an oil pan) on a car is usually about 4 quarts. The size on Lycoming and Continental is 8 quarts so the CAR is a much smaller capacity. And capacity has nothing to do with it. It is the environment and the number of hours flown. 3 - Yes cars do go for hunderds of thousands of miles. The average car is used EVERYDAY do you fly your plane everyday? Not a good comparison. 4 - DIESEL - Diesel fuel is why diesel engines are pre-heated NOT the compression ratio. The GLOW PLUGS on a diesel are there to START COMBUSTION by pre-heating the inside of the cylinder. They are kept glowing by the combustion process. Diesel fuel GELS at low temperatures, a gelled fuel is extremely difficult to burn. Want to learn something - Take a small 3" diameter pan. Put in 1/8" of diesel fuel. Throw a match into it. What do you thinks will happen? NOTHING! NOTHING - The match will go out. That should show you how POOR diesel fuel is as an accelerant. My Diesel Rabbit had two pre heaters, one in the dipstick and one on the oil pan. Both raised the temp under the hood enough to heat a Metal Cased Cartage Oil Filter enough to prevent gelling. Oh, I live in NJ so I get both hot and cold temps. 5 - You did not comprehend my last post. WATER is also added to the oil through COMBUSTION. ALL the water is NOT boiled off as you think. Other wise why is there water vapor (Steam) coming out of your oil cap when opened. 6 - Yes I am worried about effects of cold starts - After all I have $18,000 invested in my engine NOT counting the plane, or the people that fly in it. 7 - Seven as in CRAPS you loose - " If it was a serious issue, you sure would have at least seen a procedure for how to do it in the engine owner's manual." You are so willing blindly trust a manual as to not use common sense and consider who ever wrote and accepted the manual could have missed writing the section on COLD STARTS! OR - OR you don't think BUSINESS comes before common sense? Think on how many planes are built WITHOUT a cowl. How do you preheat an engine without a cowl? How many engines would NOT be sold if the plane was to be used in colder areas such as NJ - IF - The manual said: Pre-heat at 32 F and below. RTFQS Barry On Thu, Nov 15, 2012 at 11:42 AM, Gerry Visel wrote: > Barry, > > Do you preheat your car? With it's big oil sump, you'll see lots more > water there. Somehow they last for many hundreds of thousands of miles > without (most people) preheating. (If you drive a diesel, this does not > apply due to the higher compression ratios. I preheated my old Benz, even > with its glow plugs, to help it turn over easier.) However, water > in engines all gets boiled off during operation, so the only water you will > see is from what might have condensed inside since last shutdown. I think > you are worried too much about its effects. If it was a serious issue, you > sure would have at least seen a procedure for how to do it in the engine > owner's manual. > > That said, I sure agree that it is sure a whole lot easier to start a > pre-heated engine when it is really cold outside! > > Gerry > > On Thu, Nov 15, 2012 at 7:46 AM, FLYaDIVE wrote: > >> Hi Ross: >> >> There is always water in oil. Of course you reduce the quantity by >> flying often. >> An easy way to prove this to yourself is: >> After a flight - Open up your Oil Cap. What do you see coming out? A >> white vapor. That white vapor is water. Now, take a smooth sheet of >> aluminum and hold it in the vapor. What do you see? Water condensing on >> the aluminum. >> >> Part of the normal COMBUSTION process is water - >> > > * > > > * > > ________________________________ Message 6 _____________________________________ Time: 10:34:55 AM PST US Subject: Re: RotaxEngines-List: Re: Rotax 912 Preheating From: Gerry Visel Get a life, guy. On Thu, Nov 15, 2012 at 12:05 PM, FLYaDIVE wrote: > > You did not spend much time thinking through your email. > ________________________________ Message 7 _____________________________________ Time: 04:01:31 PM PST US From: rayj Subject: Re: RotaxEngines-List: Re: Rotax 912 Preheating Sorry folks, I didn't know. I've learned my lesson. Raymond Julian Kettle River, MN. "And you know that I could have me a million more friends, and all I'd have to lose is my point of view." - John Prine On 11/15/2012 12:34 PM, Gerry Visel wrote: > Get a life, guy. > > On Thu, Nov 15, 2012 at 12:05 PM, FLYaDIVE > wrote: > > > You did not spend much time thinking through your email. > > > * > > > * ------------------------------------------------------------------------------------- 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.