---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Wed 11/21/07: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:46 AM - Re: 912 oil filters (Thom Riddle) 2. 08:07 AM - Re: 912 oil filters (Roger Lee) 3. 09:13 AM - Re: Re: 912 oil filters (Dave Austin) 4. 09:22 AM - Re: Re: 912 oil filters (Peter Jeffers) 5. 09:47 AM - Fw: Re: Rotax Oil Filter Question (rampil) 6. 11:21 AM - Re: 912 oil filters (Roger Lee) 7. 12:39 PM - Re: Re: 912 oil filters (Roger Roy) 8. 04:15 PM - Re: 912 oil filters (Roger Lee) 9. 06:09 PM - Re: Re: 912 oil filters (Noel Loveys) 10. 06:37 PM - Re: Re: 912 oil filters (rlborger) 11. 06:41 PM - Re: Re: 912 oil filters (Noel Loveys) 12. 06:43 PM - Re: 912 oil filters (Roger Lee) 13. 07:10 PM - Re: Re: 912 oil filters (rlborger) ________________________________ Message 1 _____________________________________ Time: 05:46:15 AM PST US Subject: RotaxEngines-List: Re: 912 oil filters From: "Thom Riddle" I can't let Dean Vogel's response to the question from Bob Borger go by without being contested. What exactly does the 120F oil temperature minimum before going to full power have to do with oil filter bypass pressure???? The answer: Almost NOTHING! The 120F oil temperature minimum is to prevent the operator from risking damage to the engine by going to take-off power while the engine is cold. The oil pressure by-pass valve is to permit oil to flow to the engine if the filter is clogged from debris or sludge. One has almost nothing at all to do with the other. My A&P I/A partner in our Allegro attended Dean's 4-stroke class last April. It took about 1 1/2 hours into Dean's class (last April) before we realized that this guy does not know much about engines. He regurgitates what he is told. It is my understanding that he is an electrical engineer with zero mechanical background other than what he has "learned" (memorized?) from Lockwood. When you ask him a question he has not already been told the answer to, if he is smart he will say I don't know, which is a fair and proper answer. But when he makes up stuff based on suppositions without understanding what he is talking about, he has gone too far. That said, this does not mean that everything that is taught in his class is not worthwhile and good information for 912 operators but if he goes outside of the class syllabus, he may be making stuff up on the fly, like linking the minimum oil temp to oil filter by-pass pressure. The only linkage there is is a minor one. That is, when oil is cold its viscosity is higher than when warm and oil pressure will be higher than when warm. BUT this difference in viscosity (and pressure) between cold and hot oil (especially in multi-weight oils) is not sufficient to make a difference in oil filter by-pass valve operation unless the filter is nearly clogged anyway. That will only happen if the recommended oil and filter change interval and tank cleaning have been ignored for quite a long time. Thom in Buffalo FAA Powerplant Mechanic Retired Mechanical Engineer -------- Thom in Buffalo N221FA Allegro 2000 912UL N197BG FS1/447 -------------------- We hang the petty thieves and appoint the great ones to public office. - Aesop Read this topic online here: http://forums.matronics.com/viewtopic.php?p=147677#147677 ________________________________ Message 2 _____________________________________ Time: 08:07:14 AM PST US Subject: RotaxEngines-List: Re: 912 oil filters From: "Roger Lee" Hi Thom, I couldn't agree more with the statement that quite a few people teach or give out info that has been handed down from person to person and no real science to back it up. I know we all like to believe our teachers are always right, but we sometimes have to question where did they get their info and challenge that sometimes. I do in classes I take and I expect that in classes I teach. When I teach and don't know an answer I say so then go look it up or ask if anyone in the class has any insight. Some people who attend classes are as sharp or more informed than the teacher. I have backed teachers in the corner with oil filter or technical questions and they finally have to break down and just say that was what I was told. I agree that an oil temp of 120F has nothing to do with the bypass pressure. This is just the temp that Rotax specifies before running the engine to full operating rpm. Like I have said if your bypass is operating then you have bigger issues. I wonder if Toyota would make such a big stink if someone used a Rotax oil filter on one of their cars? It does fit several Toyota models. That's what the other filters in my last post fit along with a few other foreign cars. Hope they aren't too mad about the bypass opening at start up that no one told them about. :D -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=147699#147699 ________________________________ Message 3 _____________________________________ Time: 09:13:21 AM PST US From: "Dave Austin" Subject: Re: RotaxEngines-List: Re: 912 oil filters I've used the Toyota V6 oil filter for 14 years on my 912. Not using a drop of oil yet. 650 hours. Started doing that because I had a V6 Toyota! Dave Austin 601HDS - 912, Spitfire Mk VIII ________________________________ Message 4 _____________________________________ Time: 09:22:28 AM PST US From: "Peter Jeffers" Subject: RE: RotaxEngines-List: Re: 912 oil filters Hi Thom, As one retired engineer to another my only comment is that when the engine is cold the oil is more viscous and risk associated with applying higher power settings is excessive oil px. Excess pressure is limited by the oil pressure relief valve (which is part of the engine oil px circuit and not the filter). The pressure relief valve in the filter opens in response to a high pressure drop over the filter element and simply bypasses the element. It does little to the engine oil px itself. Indeed, if anything, the engine oil px may increase slightly when the by pass valve opens. Could this be where confusion comes from. Pete -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Thom Riddle Sent: 21 November 2007 13:44 Subject: RotaxEngines-List: Re: 912 oil filters I can't let Dean Vogel's response to the question from Bob Borger go by without being contested. What exactly does the 120F oil temperature minimum before going to full power have to do with oil filter bypass pressure???? The answer: Almost NOTHING! The 120F oil temperature minimum is to prevent the operator from risking damage to the engine by going to take-off power while the engine is cold. The oil pressure by-pass valve is to permit oil to flow to the engine if the filter is clogged from debris or sludge. One has almost nothing at all to do with the other. My A&P I/A partner in our Allegro attended Dean's 4-stroke class last April. It took about 1 1/2 hours into Dean's class (last April) before we realized that this guy does not know much about engines. He regurgitates what he is told. It is my understanding that he is an electrical engineer with zero mechanical background other than what he has "learned" (memorized?) from Lockwood. When you ask him a question he has not already been told the answer to, if he is smart he will say I don't know, which is a fair and proper answer. But when he makes up stuff based on suppositions without understanding what he is talking about, he has gone too far. That said, this does not mean that everything that is taught in his class is not worthwhile and good information for 912 operators but if he goes outside of the class syllabus, he may be making stuff up on the fly, like linking the minimum oil temp to oil filter by-pass pressure. The only linkage there is is a minor one. That is, when oil is cold its viscosity is higher than when warm and oil pressure will be higher than when warm. BUT this difference in viscosity (and pressure) between cold and hot oil (especially in multi-weight oils) is not sufficient to make a difference in oil filter by-pass valve operation unless the filter is nearly clogged anyway. That will only happen if the recommended oil and filter change interval and tank cleaning have been ignored for quite a long time. Thom in Buffalo FAA Powerplant Mechanic Retired Mechanical Engineer -------- Thom in Buffalo N221FA Allegro 2000 912UL N197BG FS1/447 -------------------- We hang the petty thieves and appoint the great ones to public office. - Aesop Read this topic online here: http://forums.matronics.com/viewtopic.php?p=147677#147677 17:44 17:44 ________________________________ Message 5 _____________________________________ Time: 09:47:23 AM PST US Subject: RotaxEngines-List: Fwd: RE: Rotax Oil Filter Question From: "rampil" Ron, Recall for a moment that Issettas are not a good model of the Rotax 9xx. Recall that that the Rotax has tiny oil galleries all over for cooling The Rotax has hydraulic lifters with tiny oil channels The Rotax cylinder heads are tempered aluminum alloy which will soften dramatically if overheated. Clogged channels hurt engine, just like at all the precautions against air bubbles in the galleries! There are other reasons as well. I am sure you will not unfilter your nice unflown 914 when the time comes, so it doesn't seem reasonable to frame your question in such a way as to suggest it to others, -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=147723#147723 ________________________________ Message 6 _____________________________________ Time: 11:21:28 AM PST US Subject: RotaxEngines-List: Re: 912 oil filters From: "Roger Lee" Hi Guys, Straight viscosity oil acts differently in hot and cold than a multi viscosity. The multi viscosity oil has and additive to give it its unique properties when cold and to change when it's hot. Multi viscosity oil has to thin in colder engine climates and thicken in hotter climates. Just look at the use charts for oils and climate temps. That's why some in very cold climates may use a 5-20w verses someone in a hotter climate using a 20-50w. 5w oil works better in colder climates. In the older days when people would use just a straight weight Dino based oil like a 30w and they lived in Montana and it was the middle of the winter and they didn't have a block heater they couldn't even get the engine to turn over. Todays synthetics and good multi viscosity oils don't have as big an issue with the cold as the older straight weight Dino based oils did of yesteryear. That said some experts recommend that nothing less than a 10-40w be used in anything that uses the engine oil in the transmission. A 10-40w oil can get down to some pretty cold temps., at least for this Arizona boy. Some even recommend 20-50w if used in both. To each his own on that subject. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=147749#147749 ________________________________ Message 7 _____________________________________ Time: 12:39:21 PM PST US From: "Roger Roy" Subject: Re: RotaxEngines-List: Re: 912 oil filters Well Dave that is one opener, The Rotax has been around for 14 years????? It wasn't long ago that the 2 cycle 532 was the best they had until the aircraft designated 582 came along than finally the 9XX series. This is one great list because I learned something today, thanks RJ To: rotaxengines-list@matronics.com Sent: Wednesday, November 21, 2007 12:03 PM Subject: Re: RotaxEngines-List: Re: 912 oil filters > I've used the Toyota V6 oil filter for 14 years on my 912. Not using a drop of oil yet. 650 hours. Started doing that because I had a V6 Toyota! Dave Austin 601HDS - 912, Spitfire Mk VIII http://www.matronics.com/contribution http://www.matronics.com/Navigator?RotaxEngines-List ________________________________ Message 8 _____________________________________ Time: 04:15:22 PM PST US Subject: RotaxEngines-List: Re: 912 oil filters From: "Roger Lee" The 912 has been around since about late 1989. As they say the rest is history. I believe Rotax pumps out approximately 6500-7000 engines a year. I don't think any other aircraft mfg. is producing that many a year. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=147793#147793 ________________________________ Message 9 _____________________________________ Time: 06:09:25 PM PST US From: "Noel Loveys" Subject: RE: RotaxEngines-List: Re: 912 oil filters Roger: Considering the auto filters by pass at a slightly lower pressure and the automotive oil probably gets much more of a beating than the aviation application. Do you really think the Toyota engineers don't know about the bypass opening on start up?? Especially on all cars sold North of the 49th in the winter months. After all that's why the by pass is there.. To allow oil to flow and not blow some other component because of high pressure. I have seen an oil cooler that was on an IO-540 after it ruptured on a sub zero start up. They didn't have the pressure by pass oil cooler on that engine and it became the weakest link.... D...messy too. Noel Hope they aren't too mad about the bypass opening at start up that no one told them about. :D > > -------- > Roger Lee > Tucson, Az. ________________________________ Message 10 ____________________________________ Time: 06:37:31 PM PST US From: rlborger Subject: Re: RotaxEngines-List: Re: 912 oil filters Thom, The only part of your response I will strenuously argue with it the "making it up" comment. If Dean did not know the answer to a question, he admitted it without hesitation and went to what ever source was necessary to find the proper answer which was provided at the next possible class opportunity. Dean is an engineer, former USAF pilot and test pilot, test pilot and engineer for one of those plastic aircraft (I don't remember if it was Cirrus or Columbia) prior to joining Lockwood. He gave us his complete background when he began the class. He admitted that he was new to the Rotax and was continuing to learn about the engine as time and his class experience went on. I found him honest and straight forward. And I wouldn't expect him to teach anything that is contrary to Rotax requirements. He will teach straight by the Rotax books. Bob Borger On Nov 21, 2007, at 7:44 AM, Thom Riddle wrote: > > > I can't let Dean Vogel's response to the question from Bob Borger > go by without being contested. > > What exactly does the 120F oil temperature minimum before going to > full power have to do with oil filter bypass pressure???? The > answer: Almost NOTHING! > > The 120F oil temperature minimum is to prevent the operator from > risking damage to the engine by going to take-off power while the > engine is cold. The oil pressure by-pass valve is to permit oil to > flow to the engine if the filter is clogged from debris or sludge. > One has almost nothing at all to do with the other. > > My A&P I/A partner in our Allegro attended Dean's 4-stroke class > last April. It took about 1 1/2 hours into Dean's class (last > April) before we realized that this guy does not know much about > engines. He regurgitates what he is told. It is my understanding > that he is an electrical engineer with zero mechanical background > other than what he has "learned" (memorized?) from Lockwood. When > you ask him a question he has not already been told the answer to, > if he is smart he will say I don't know, which is a fair and proper > answer. But when he makes up stuff based on suppositions without > understanding what he is talking about, he has gone too far. > > That said, this does not mean that everything that is taught in his > class is not worthwhile and good information for 912 operators but > if he goes outside of the class syllabus, he may be making stuff up > on the fly, like linking the minimum oil temp to oil filter by-pass > pressure. The only linkage there is is a minor one. That is, when > oil is cold its viscosity is higher than when warm and oil pressure > will be higher than when warm. BUT this difference in viscosity > (and pressure) between cold and hot oil (especially in multi-weight > oils) is not sufficient to make a difference in oil filter by-pass > valve operation unless the filter is nearly clogged anyway. That > will only happen if the recommended oil and filter change interval > and tank cleaning have been ignored for quite a long time. > > Thom in Buffalo > FAA Powerplant Mechanic > Retired Mechanical Engineer > > -------- > Thom in Buffalo > N221FA Allegro 2000 912UL > N197BG FS1/447 > -------------------- > We hang the petty thieves and appoint the great ones to public office. > - Aesop > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=147677#147677 > > ________________________________ Message 11 ____________________________________ Time: 06:41:56 PM PST US From: "Noel Loveys" Subject: RE: RotaxEngines-List: Re: 912 oil filters Roger: That was very well written. I learned a lot from that post. There is just one thing though.....(darn!) I doubt there is a car in the lower 48 that the filter by passes on every start up. This far North when on a cold frosty morning when the temperature is close to 0F and the car has about three thousand miles on the oil and you can feel the strain of the starter motor as the engine grinds over you can bet the filter by pass will open and will stay open until the viscosity of the oil decreases. As you said this is not an instantaneous thing the pressure takes time to build up. It's just that it continues to build for as long as several minutes. This is a good reason why not to start your engine and drive off on a cold winter morning. A couple of minutes at the idle ( fast idle FI) can be a real engine saver and allow the oil a chance to circulate. I used to live in Labrador. That was over thirty years ago when the earth was still green. The major problems we had in those days were automatic transmission oil becoming too viscous to work properly and sometimes hydraulic fluid in brake slave cylinders would make the foot break on a car feel like stepping on something the consistency of a brick. Manual transmissions were sometimes all but impossible to get in gear and you could time the clutch engaging with a calendar if it had a hydraulic actuator. If you were fortunate enough to get your brakes to apply you might have to wait five minutes for them to release. A few minutes with a partially applied brake would generate enough heat to free up the brakes again. No one, and I mean no one was dumb enough to ever apply the hand brake in the winter! Noel > -----Original Message----- > From: owner-rotaxengines-list-server@matronics.com > [mailto:owner-rotaxengines-list-server@matronics.com] On > Behalf Of Roger Lee > Sent: Wednesday, November 21, 2007 1:46 AM > To: rotaxengines-list@matronics.com > Subject: RotaxEngines-List: Re: 912 oil filters > > > > > Here's my reply in an attachment. At least I got to type it > out and send it this time. [Laughing] > > It's a Word document. > > -------- > Roger Lee > Tucson, Az. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=147643#147643 > > > > > Attachments: > > http://forums.matronics.com/files/oil_filters_123.doc > > > > > > > > ________________________________ Message 12 ____________________________________ Time: 06:43:13 PM PST US Subject: RotaxEngines-List: Re: 912 oil filters From: "Roger Lee" Hi Noel, I agree that under adverse conditions any thing can happen, but under our usual or normal circumstances what would happen to one filter would have probably happened to the other. I believe automotive oil gets dirtier faster because of all the types of driving that is done in and around a city. Our aircraft engines don't see the stop and go, as much throttle use and we tend to change oil more regularly than some in cars. 50w oil will flow through these filters so why would 20w cause a bypass to open. Nothing is blocking the upstream or downstream part of the filter medium and at our start up oil pressure and high rpm's are not instantaneous. I think some people just look for issues that aren't really there to make what they have heard sound true or at least reasonable. We do need shear additives for our Rotax engines just like motorcycles do for the gearbox. The gearbox beats on the oil. Not to make it dirtier, that's just carbon from the combustion process that is being removed and that means the oil is doing its job. The issue with our oil in the gearbox is that the better the shear additives the less an oil will lose some of its viscosity and gearbox protection. Just because an oil is black doesn't mean it is not doing a good job lubricating. To really see if your oil is breaking down it needs to be sent to a lab. We change ours so often I seriously doubt anyone of us is having an oil breakdown problem. Unless my temps in Tucson, Az get below 20F I use 20-50w motorcycle Amsoil all year. More for the gearbox than the engine and we get pretty warm in the summer. Our normal winter month temps are in the 30's for the lows, some in the 40's and some in the high 20's. -------- Roger Lee Tucson, Az. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=147815#147815 ________________________________ Message 13 ____________________________________ Time: 07:10:41 PM PST US From: rlborger Subject: Re: RotaxEngines-List: Re: 912 oil filters Roger, I too agree that quite a few people teach or give out info that has been handed down from person to person with no real science or engineering to back it up. That's why there's a lot of very bad information floating around the web about the care and feeding of the Rotax engines. Mostly from well meaning people with a lot of experience dealing with Lycoming and Continental and automotive engines. The Rotax isn't your grandpa's LyCosarus and requires some significantly different care and feeding. That's why I went to the Rotax course. As for Toyota making a stink about using a Rotax oil filter, yup, probably would if something went wrong in the engine. Probably void your warranty. Good building and great flying, Bob Borger On Nov 21, 2007, at 10:05 AM, Roger Lee wrote: > > > Hi Thom, > > I couldn't agree more with the statement that quite a few people > teach or give out info that has been handed down from person to > person and no real science to back it up. I know we all like to > believe our teachers are always right, but we sometimes have to > question where did they get their info and challenge that > sometimes. I do in classes I take and I expect that in classes I > teach. When I teach and don't know an answer I say so then go look > it up or ask if anyone in the class has any insight. Some people > who attend classes are as sharp or more informed than the teacher. > I have backed teachers in the corner with oil filter or technical > questions and they finally have to break down and just say that was > what I was told. > > I agree that an oil temp of 120F has nothing to do with the bypass > pressure. This is just the temp that Rotax specifies before running > the engine to full operating rpm. Like I have said if your bypass > is operating then you have bigger issues. > > > I wonder if Toyota would make such a big stink if someone used a > Rotax oil filter on one of their cars? It does fit several Toyota > models. That's what the other filters in my last post fit along > with a few other foreign cars. Hope they aren't too mad about the > bypass opening at start up that no one told them about. :D > > -------- > Roger Lee > Tucson, Az. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=147699#147699 > > ------------------------------------------------------------------------------------- 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.