---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Tue 04/20/10: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:24 AM - Re: RotaxEngines-List Digest: 9 Msgs - 04/19/10 (Vince Hallam) 2. 05:57 AM - Re: RotaxEngines-List Digest: 9 Msgs - 04/19/10 (lucien) 3. 07:58 AM - Re: Fuel consumption for the 912S (John Goodings) 4. 08:24 AM - Re: Re: RotaxEngines-List Digest: 9 Msgs - 04/19/10 (Richard Girard) 5. 10:38 AM - Re: Re: RotaxEngines-List Digest: 9 Msgs - 04/19/10 (Guy Buchanan) 6. 02:40 PM - Re: Re: Fuel consumption for the 912S (Gilles Thesee) ________________________________ Message 1 _____________________________________ Time: 05:24:23 AM PST US From: Vince Hallam Subject: RotaxEngines-List: Re: RotaxEngines-List Digest: 9 Msgs - 04/19/10 My experience of declutched freewheeling propellers is that in event of engine off, glide distance is significantly reduced, perhaps worse than half. This in turn cuts reachable landing spots to a quarter as well as reducing time available. Yes you can use it intentionally like a spoiler or flap, but you cant "reduce flap" to penetrate ahead. Also the disturbed airflow over the tail can give you a nasty surprise whe you try to do an accurate landing flare Vince Hallam Torquay, Devon, TQ1 3LZ www.devonwindmills.co.uk On Tue, Apr 20, 2010 at 7:58 AM, RotaxEngines-List Digest Server wrote: > * > > ================================================= > 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&View=html&Chapter 10-04-19&Archive=RotaxEngines > > Text Version: > > http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Chapter 10-04-19&Archive=RotaxEngines > > > =============================================== > EMail Version of Today's List Digest Archive > =============================================== > > > ---------------------------------------------------------- > RotaxEngines-List Digest Archive > --- > Total Messages Posted Mon 04/19/10: 9 > ---------------------------------------------------------- > > > Today's Message Index: > ---------------------- > > 1. 08:37 AM - Re: Fuel consumption for the 912S (John Goodings) > 2. 09:06 AM - Re: Re: Why exactly shouldn't you run a 914 without a prop? (Noel Loveys) > 3. 09:08 AM - Re: Re: Why exactly shouldn't you run a 914 without a prop? (Gilles Thesee) > 4. 09:14 AM - Re: Re: Fuel consumption for the 912S (Gilles Thesee) > 5. 11:34 AM - Re: Why exactly shouldn't you run a 914 without a prop? (rparigoris) > 6. 01:29 PM - Re: Why exactly shouldn't you run a 914 without a prop? (rparigoris) > 7. 03:15 PM - Re: 912s motor mount question (Guy Buchanan) > 8. 03:52 PM - Re: Why exactly shouldn't you run a 914 without a prop? (lucien) > 9. 07:06 PM - Desser 4.00-6 8 ply and 6 ply LSA tire (Roger Lee) > > > ________________________________ Message 1 _____________________________________ > > > Time: 08:37:05 AM PST US > From: John Goodings > Subject: RotaxEngines-List: Re: Fuel consumption for the 912S > > > People have been quoting fuel consumption figures for the Rotax 914 > recently. The figures quoted seem rather high. What fuel consumption do > people get with the Rotax 912S (100 HP)? We have measured it pretty > carefully over quite a number of hours, and we are getting slightly under > 16 litres/hr (4.34 U.S. gal/hr) at 5200 RPM cruise. We use mainly 91 > octane mogas without ethanol additive, but probably 1/3 of the fuel used > is 100 LL because we don't have a choice at many small airports in > Ontario. Here are other details of our aircraft, but I'm not sure they > are very relevant to fuel consumption. Our aircraft is a CH601HD with a > 66-inch, 3-blade, GSC prop flying with 2 people (and 1 small Italian > greyhound!) near 1200 lbs gross weight. Because of that thick wing, our > cruise is only about 100-105 mph. > > John Goodings, C-FGPJ, CH601HD with R912S, Carp/Ottawa/Toronto. > > > ________________________________ Message 2 _____________________________________ > > > Time: 09:06:03 AM PST US > From: "Noel Loveys" > Subject: RE: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 without > a prop? > > > Lucien: > > Dave has a video up on you tube where he hand props a 582 in the middle of > winter up to his backside in snow. While rotax has good pull cord starters > they have to come off to put on the standard electric starter. Being able > to hand prop a plane can be literally a life saver on a cold Ontario day. > > Noel > > -----Original Message----- > From: owner-rotaxengines-list-server@matronics.com > [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of lucien > Sent: April 17, 2010 12:36 PM > Subject: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 without > a prop? > > > dave wrote: >> Not able to hand prop >> extra parts that "could " give troubles >> >> giant airbrake >> >> >> --- > > > Er, that hardly qualifies as a large set of cons outweighing the (much > larger) set of pros of using the RK-400 clutch. > > Like I said, most of the folks who go on about how worthless the clutch is > have very little, if any, time on a clutch-equipped engine/airplane. > > No hand propping is a good try, but I'm not too convinced - the Rotax > 2-strokes come with an excellent pull-rope starting system that is very > reliable and gives little trouble. Even if, say the rope pulls out of the > handle, the pull start is easily fixable in the field with a few hand tools > you can keep in your flight bag. So it'd be rare indeed that you'd have to > resort to hand starting (a very dangerous proposition on many pusher designs > anyway). > If you put a mag-end electric start on Rotax 2-stroke, you get what you > deserve anyway. At that point you should have gone with the E box which > addresses that concern already. > > I totally don't buy the extra-trouble argument. The RK-400 is a very well > designed, heavy-duty item that lasts simply forever. On my FSII, the > original engine was starting to wear out (at about 400 hours) before even a > few _thousandths_ had been worn off the original set of shoes (I still have > them out in the hangar in fact). The RK-400 was tested on the 618 and > couldn't be made to slip or otherwise give any trouble at all even on that > huge monster. > > The giant airbrake argument is another I get all the time from folks who > don't run the clutch. They don't realize, for example, that when the clutch > is disengaged in the air (engine-idle), the plane flies _exactly_ as it > would with the engine off. So you can _exactly_ replicate the engine off > situation in your emergency procedure practice without having to shut the > engine down. This makes getting familiar with the engine-off glide much > safer to practice - i.e. if you really do happen to screw up an approach > during practice you're not in a real emergency if you can't get the cold > engine started again. > > So on that day when the engine actually does stop for real, you're not > dangerously trying to stretch a glide you've hardly ever practiced in the > case of a fixed prop. Instead, it's exactly the same condition you've > already practiced a million times before, greatly increasing your chances of > a successful descent and landing. > > Sorry, don't buy this one either ;) > > LS > > -------- > LS > Titan II SS > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=294535#294535 > > > ________________________________ Message 3 _____________________________________ > > > Time: 09:08:43 AM PST US > From: Gilles Thesee > Subject: Re: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 without > a prop? > > > Hi Ron, >> I will use on my 914 series with bypass fuel systems, with added >> Europa twist of adding a second Andair 375 Gasculator to allow second >> pump to have ability to draw from another source. I willl only use >> Wacker spark plug thermal conductive compound. > Add to that adequate cooling of the engine, with a correctly designed > cooling duct and cowl flap. > >> I will check Carbon Monoxide levels above 100% power. I will if my >> life were threatened by the wastegate opening, would follow DO >> procedure in operators manual to leave it closed until obsticle is >> cleared. > Concerning the wastegate ensure good lubrication, and monitor the MP > during the takeoff run and initial climbout. In our project, when > operating from a low level aerodrome, takeoff takes place about 10 > seconds after releasing the brakes and power reduction to 100% about 5 > seconds later. > >> I can go on and on, but if anyone is not following the above procedure >> does it make them unsafe or putting life and engine at risk? If you >> don't follow Mfgs. procedure perhaps the answer perhaps is yes, >> perhaps no, need to take on a case by case basis. Rotax is not an >> absolute advocate of only flying a 914 with a differential pressure >> gauge IMHO they should be. > The initial subject was avoiding mishandling of the engine. > Yes monitoring the fuel pressure could add to the pilot's peace of mind, > but it has no influence on the running of the engine. We monitor FF > during takeoff. > >> BTW, did you ever verify with Carbon Monoxide test as suggested or >> required by Rotax (older serial number engines and if you have a >> Intercooler it is a requirement) that you are running rich enough on >> all 4 cylinders above 100% power? If you didn't use Carbon Monoxide >> detector, how did you verify? > Will verify if it applies to our engine. For the time being, plugs seem > to be OK. > > Best regards, > -- > Gilles > http://contrails.free.fr > > > ________________________________ Message 4 _____________________________________ > > > Time: 09:14:25 AM PST US > From: Gilles Thesee > Subject: Re: RotaxEngines-List: Re: Fuel consumption for the 912S > > > John, >> >> People have been quoting fuel consumption figures for the Rotax 914 >> recently. The figures quoted seem rather high. > About 21 litre/h is quite normal for a 100 hp engine cruising at 75%, be > it a Rotax, a Jabiru or a Lyco/Conti. > >> What fuel consumption do people get with the Rotax 912S (100 HP)? We >> have measured it pretty carefully over quite a number of hours, and we >> are getting slightly under 16 litres/hr (4.34 U.S. gal/hr) at 5200 RPM >> cruise. > > 16 L/h corresponds to about 60% power with a 100 hp. > Are you talking of *cruise* consumption, or overall consumption ? If you > are doing much circuit work, low numbers are normal, since you are most > of the time at part throttle. > > > Best regards, > -- > Gilles > http://contrails.free.fr > > > ________________________________ Message 5 _____________________________________ > > > Time: 11:34:34 AM PST US > Subject: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 without a prop? > From: "rparigoris" > > > Hi Gilles > "Yes monitoring the fuel pressure could add to the pilot's peace of mind, > but it has no influence on the running of the engine. We monitor FF > during takeoff." > Lack of differential fuel pressure on take off leads to "running" of the pilot > when engine plays mellow song of "silent night". You need between ~ 2 and 5 PSI > differential. If low you could get proper fuel flow but on verge of not being > able to meet crack pressure of fuel pressure regulator. Problem is if you have > full float bowls and begin take off run, you will be in air with perhaps not > enough runway to land on when they run out. Also when cruising it gives you > a heads up to close at hand failure. Most culprits of low differential pressure > is clogged fuel filter or gasculator/s. If you reduce power and can attain 2 > PSI then you could probably gain yourself a little more time. At altitude where > the pumps have to work hardest are where you will first see lower readings, > a lower altitude may allow you to reach airport. Running lean at altitude is > a very bad thing to do, fuel flow may be fine at less than 2 PSI, but go too much > lower and fuel flow will suffer. Differential can give you a heads up to problem > before it happens. > Ron Parigoris > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=294863#294863 > > > ________________________________ Message 6 _____________________________________ > > > Time: 01:29:12 PM PST US > Subject: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 without a prop? > From: "rparigoris" > > > Heres someone else running without a prop. No question it revs quickly, but not > unlike many motorcycles: > http://www.youtube.com/watch?v=tUrFJi93MIo > Jason, is this you? > Ron Parigoris > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=294872#294872 > > > ________________________________ Message 7 _____________________________________ > > > Time: 03:15:57 PM PST US > From: Guy Buchanan > Subject: Re: RotaxEngines-List: 912s motor mount question > > > At 09:59 AM 4/18/2010, you wrote: >>I am still having a fight with the water pump being in the way. > > Being in the way of what? Can you provide pictures? (Please make them small.) > > Thanks, > > > Guy Buchanan > San Diego, CA > K-IV 1200 / 582-C / Warp / 400 hrs. and counting > > > ________________________________ Message 8 _____________________________________ > > > Time: 03:52:16 PM PST US > Subject: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 without a prop? > From: "lucien" > > > Float Flyr wrote: >> Lucien: >> >> Dave has a video up on you tube where he hand props a 582 in the middle of >> winter up to his backside in snow. While rotax has good pull cord starters >> they have to come off to put on the standard electric starter. Being able >> to hand prop a plane can be literally a life saver on a cold Ontario day. >> >> Noel >> >> -- > > > Well, for sure if you need to be able to hand prop, no, you don't want to install > the clutch. And FWIW, the clutch does have some down sides so it's not a one-size-fits-all > addition. > > I've always flown pushers and so they weren't ever very safe to hand start. But > there was also room for the pull start too, so I wasn't in the situation of say > the Kitfox. But I'd usually carry a spare rope and some extra tools enough > to be able to do a field fix of a starter if the rope pulled out or something > like that. > > One time the handle pulled off the end of the rope on my quicksilver. luckily there > was already a knot in the rope a little further downstream so it didn't suck > the rope all the way into the housing. Whew... I tied another knot and took > off.... > > LS > > -------- > LS > Titan II SS > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=294894#294894 > > > ________________________________ Message 9 _____________________________________ > > > Time: 07:06:20 PM PST US > Subject: RotaxEngines-List: Desser 4.00-6 8 ply and 6 ply LSA tire > From: "Roger Lee" > > > Hi All, > > I had a nice and pleasant chat with a Desser supervisor today. After installing > these tires (4.00-6 8 ply) on a few of different aircraft here is what I have > found and discussed with Desser. First these tires do not come pre-balanced and > you will need to do that with some of the stick-on weights. It takes about > 1.25 oz. of weight to balance these. I used the 1/4 oz. weights. I put some on > the inside and out side of the wheel. No big sweat they balance right up in a > couple of minutes. > Here is the big discussion. We started off with 30 psi on the 4.00-6 8 plys. At > 30 psi these tires seem to have a flat spot and were all bad tires. Not so fast > Hass! > Talking to Desser these tires are not meant to run that low. The pressure of 29 > psi was for the original CT tires. They prefer to have at least 62 psi in these > tires if possible. That is little too much for us so we decided on 55-57 psi > and this took the so called flat spot out of the tire. These tires are absolutely > dependent on having enough psi to keep them nice and round. Even with this > if you hold a straight edge up to them they seem ever so slightly off. So I > went out and checked 3 other aircraft with other tires and found exactly the > same thing. No tire is 100% round and is dependent on the proper pressure to maint > that roundness. The less pressure under the recommended the worse it became. > It is the same for the 6 plys and other brands of tires from what I can find. > When you balance these tires and inflate them to 55 psi you will not have > any issues with vibration. I check my 6.00-6 tires and others and they were the > same even though I didn't have to balance them. I am trying hard to get Desser > to pre-balance these tires like they do the larger tires and I believe we have > a good shot at this happening. I'll keep you informed as I do a little more > research for Desser and get some feed back. > These seem to be good tires, but need proper inflation. How much psi are the old > Italian Mark Engegno wheels good for, I don't know. > > Like they used to say: > Stay tuned and don't touch that dial! > > > If your old you'll remember this saying and if you don't then you probably don't > remember Might Mouse either. [Laughing] > > -------- > Roger Lee > Tucson, Az. > Light Sport Repairman - Maintenance Rated > Rotax Repair Center > 520-574-1080 > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=294919#294919 > > ________________________________ Message 2 _____________________________________ Time: 05:57:15 AM PST US Subject: RotaxEngines-List: Re: RotaxEngines-List Digest: 9 Msgs - 04/19/10 From: "lucien" vince(at)devonwindmills.c wrote: > My experience of declutched freewheeling propellers is that in event > of engine off, glide distance is significantly reduced, perhaps worse > than half. > This in turn cuts reachable landing spots to a quarter as well as > reducing time available. Yes you can use it intentionally like a > spoiler or flap, but you cant "reduce flap" to penetrate ahead. > Also the disturbed airflow over the tail can give you a nasty surprise > whe you try to do an accurate landing flare > Vince Hallam > > Torquay, Devon, TQ1 3LZ > > www.devonwindmills.co.uk > Er...., With my clutch equipped FSII I noticed neither of these problems. Compared to another FSII that ran a 66" TPI on a 503 B box (no clutch), my glide ratio engine-off was noticeably less than his when engine-off, but nowhere near worse by half. Also, I never noticed any disturbed airflow over the tail due to the freewheeling prop. Rudder and elevator control was nominal at all times. At engine-idle, it glided like a Kolb with no troubles or wierdness at all. The drag effect could be more on a front engined tractor where the prop is unobstructed, tho. But on my Kolb, it was a non-event. LS -------- LS Titan II SS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=294947#294947 ________________________________ Message 3 _____________________________________ Time: 07:58:38 AM PST US From: John Goodings Subject: RotaxEngines-List: Re: Fuel consumption for the 912S Gilles: My figure of 16 litres/hr (4.34 U.S. gal/hr) refers to takeoff at Carp (near Ottawa), fly at 5200 RPM (about 80% power?) for 2 hours and land at Orillia Lake St. John, and the reverse trip. The figure is lower when many circuits are involved, as you suggest. In my experience, Conti/Lycos (O-200A in particular) in C-150/C-152s were never as low as this in fuel consumption. John. ________________________________ Message 4 _____________________________________ Time: 08:24:40 AM PST US Subject: Re: RotaxEngines-List: Re: RotaxEngines-List Digest: 9 Msgs - 04/19/10 From: Richard Girard Vince, that correlates pretty well with my experience. I never noticed any control issues because I almost always had to screw the power back on to make the field. The few times that I did make it was because I turned base immediately after I reduced power to idle. As for the assertion that the clutch is no worse than an engine out with prop stopped, once again, that's not my experience. The clutch is great for seaplane and towing where the landing field is alway below (watching a Moyes Dragonfly do a reasonable imitation of a Ju-87 Stuka after releasing me from tow was a sight to behold) but beyond that it's not for me. Should anyone out there in the ether be considering the Rice King, do yourself a favor and put a couple of of tapped holes in the back plate (3/8-16 UNC or 10mm X 1.5 seem like a good compromise between size and strength) so you can remove it should the need arise. It was a major PITA to get off, but now I own a customized puller should I ever have to do it again. :-} Rick Girard On Tue, Apr 20, 2010 at 7:16 AM, Vince Hallam wrote: > vince@devonwindmills.co.uk> > > My experience of declutched freewheeling propellers is that in event > of engine off, glide distance is significantly reduced, perhaps worse > than half. > This in turn cuts reachable landing spots to a quarter as well as > reducing time available. Yes you can use it intentionally like a > spoiler or flap, but you cant "reduce flap" to penetrate ahead. > Also the disturbed airflow over the tail can give you a nasty surprise > whe you try to do an accurate landing flare > Vince Hallam > > Torquay, Devon, TQ1 3LZ > > www.devonwindmills.co.uk > > > On Tue, Apr 20, 2010 at 7:58 AM, RotaxEngines-List Digest Server > wrote: > > * > > > > ================================================= > > 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&View=html&Chapter 10-04-19&Archive=RotaxEngines > > > > Text Version: > > > > > http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Chapter 10-04-19&Archive=RotaxEngines > > > > > > =============================================== > > EMail Version of Today's List Digest Archive > > =============================================== > > > > > > ---------------------------------------------------------- > > RotaxEngines-List Digest Archive > > --- > > Total Messages Posted Mon 04/19/10: 9 > > ---------------------------------------------------------- > > > > > > Today's Message Index: > > ---------------------- > > > > 1. 08:37 AM - Re: Fuel consumption for the 912S (John Goodings) > > 2. 09:06 AM - Re: Re: Why exactly shouldn't you run a 914 without a > prop? (Noel Loveys) > > 3. 09:08 AM - Re: Re: Why exactly shouldn't you run a 914 without a > prop? (Gilles Thesee) > > 4. 09:14 AM - Re: Re: Fuel consumption for the 912S (Gilles Thesee) > > 5. 11:34 AM - Re: Why exactly shouldn't you run a 914 without a prop? > (rparigoris) > > 6. 01:29 PM - Re: Why exactly shouldn't you run a 914 without a prop? > (rparigoris) > > 7. 03:15 PM - Re: 912s motor mount question (Guy Buchanan) > > 8. 03:52 PM - Re: Why exactly shouldn't you run a 914 without a prop? > (lucien) > > 9. 07:06 PM - Desser 4.00-6 8 ply and 6 ply LSA tire (Roger Lee) > > > > > > > > ________________________________ Message 1 > _____________________________________ > > > > > > Time: 08:37:05 AM PST US > > From: John Goodings > > Subject: RotaxEngines-List: Re: Fuel consumption for the 912S > > > > > > People have been quoting fuel consumption figures for the Rotax 914 > > recently. The figures quoted seem rather high. What fuel consumption do > > people get with the Rotax 912S (100 HP)? We have measured it pretty > > carefully over quite a number of hours, and we are getting slightly under > > 16 litres/hr (4.34 U.S. gal/hr) at 5200 RPM cruise. We use mainly 91 > > octane mogas without ethanol additive, but probably 1/3 of the fuel used > > is 100 LL because we don't have a choice at many small airports in > > Ontario. Here are other details of our aircraft, but I'm not sure they > > are very relevant to fuel consumption. Our aircraft is a CH601HD with a > > 66-inch, 3-blade, GSC prop flying with 2 people (and 1 small Italian > > greyhound!) near 1200 lbs gross weight. Because of that thick wing, our > > cruise is only about 100-105 mph. > > > > John Goodings, C-FGPJ, CH601HD with R912S, Carp/Ottawa/Toronto. > > > > > > ________________________________ Message 2 > _____________________________________ > > > > > > Time: 09:06:03 AM PST US > > From: "Noel Loveys" > > Subject: RE: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 > without > > a prop? > > > > > > Lucien: > > > > Dave has a video up on you tube where he hand props a 582 in the middle > of > > winter up to his backside in snow. While rotax has good pull cord > starters > > they have to come off to put on the standard electric starter. Being > able > > to hand prop a plane can be literally a life saver on a cold Ontario day. > > > > Noel > > > > -----Original Message----- > > From: owner-rotaxengines-list-server@matronics.com > > [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of > lucien > > Sent: April 17, 2010 12:36 PM > > Subject: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 > without > > a prop? > > > > > > > > dave wrote: > >> Not able to hand prop > >> extra parts that "could " give troubles > >> > >> giant airbrake > >> > >> > >> --- > > > > > > Er, that hardly qualifies as a large set of cons outweighing the (much > > larger) set of pros of using the RK-400 clutch. > > > > Like I said, most of the folks who go on about how worthless the clutch > is > > have very little, if any, time on a clutch-equipped engine/airplane. > > > > No hand propping is a good try, but I'm not too convinced - the Rotax > > 2-strokes come with an excellent pull-rope starting system that is very > > reliable and gives little trouble. Even if, say the rope pulls out of the > > handle, the pull start is easily fixable in the field with a few hand > tools > > you can keep in your flight bag. So it'd be rare indeed that you'd have > to > > resort to hand starting (a very dangerous proposition on many pusher > designs > > anyway). > > If you put a mag-end electric start on Rotax 2-stroke, you get what you > > deserve anyway. At that point you should have gone with the E box which > > addresses that concern already. > > > > I totally don't buy the extra-trouble argument. The RK-400 is a very well > > designed, heavy-duty item that lasts simply forever. On my FSII, the > > original engine was starting to wear out (at about 400 hours) before even > a > > few _thousandths_ had been worn off the original set of shoes (I still > have > > them out in the hangar in fact). The RK-400 was tested on the 618 and > > couldn't be made to slip or otherwise give any trouble at all even on > that > > huge monster. > > > > The giant airbrake argument is another I get all the time from folks who > > don't run the clutch. They don't realize, for example, that when the > clutch > > is disengaged in the air (engine-idle), the plane flies _exactly_ as it > > would with the engine off. So you can _exactly_ replicate the engine off > > situation in your emergency procedure practice without having to shut the > > engine down. This makes getting familiar with the engine-off glide much > > safer to practice - i.e. if you really do happen to screw up an approach > > during practice you're not in a real emergency if you can't get the cold > > engine started again. > > > > So on that day when the engine actually does stop for real, you're not > > dangerously trying to stretch a glide you've hardly ever practiced in the > > case of a fixed prop. Instead, it's exactly the same condition you've > > already practiced a million times before, greatly increasing your chances > of > > a successful descent and landing. > > > > Sorry, don't buy this one either ;) > > > > LS > > > > -------- > > LS > > Titan II SS > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=294535#294535 > > > > > > ________________________________ Message 3 > _____________________________________ > > > > > > Time: 09:08:43 AM PST US > > From: Gilles Thesee > > Subject: Re: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 > without > > a prop? > > > > > > Hi Ron, > >> I will use on my 914 series with bypass fuel systems, with added > >> Europa twist of adding a second Andair 375 Gasculator to allow second > >> pump to have ability to draw from another source. I willl only use > >> Wacker spark plug thermal conductive compound. > > Add to that adequate cooling of the engine, with a correctly designed > > cooling duct and cowl flap. > > > >> I will check Carbon Monoxide levels above 100% power. I will if my > >> life were threatened by the wastegate opening, would follow DO > >> procedure in operators manual to leave it closed until obsticle is > >> cleared. > > Concerning the wastegate ensure good lubrication, and monitor the MP > > during the takeoff run and initial climbout. In our project, when > > operating from a low level aerodrome, takeoff takes place about 10 > > seconds after releasing the brakes and power reduction to 100% about 5 > > seconds later. > > > >> I can go on and on, but if anyone is not following the above procedure > >> does it make them unsafe or putting life and engine at risk? If you > >> don't follow Mfgs. procedure perhaps the answer perhaps is yes, > >> perhaps no, need to take on a case by case basis. Rotax is not an > >> absolute advocate of only flying a 914 with a differential pressure > >> gauge IMHO they should be. > > The initial subject was avoiding mishandling of the engine. > > Yes monitoring the fuel pressure could add to the pilot's peace of mind, > > but it has no influence on the running of the engine. We monitor FF > > during takeoff. > > > >> BTW, did you ever verify with Carbon Monoxide test as suggested or > >> required by Rotax (older serial number engines and if you have a > >> Intercooler it is a requirement) that you are running rich enough on > >> all 4 cylinders above 100% power? If you didn't use Carbon Monoxide > >> detector, how did you verify? > > Will verify if it applies to our engine. For the time being, plugs seem > > to be OK. > > > > Best regards, > > -- > > Gilles > > http://contrails.free.fr > > > > > > ________________________________ Message 4 > _____________________________________ > > > > > > Time: 09:14:25 AM PST US > > From: Gilles Thesee > > Subject: Re: RotaxEngines-List: Re: Fuel consumption for the 912S > > > > > > John, > >> > >> People have been quoting fuel consumption figures for the Rotax 914 > >> recently. The figures quoted seem rather high. > > About 21 litre/h is quite normal for a 100 hp engine cruising at 75%, be > > it a Rotax, a Jabiru or a Lyco/Conti. > > > >> What fuel consumption do people get with the Rotax 912S (100 HP)? We > >> have measured it pretty carefully over quite a number of hours, and we > >> are getting slightly under 16 litres/hr (4.34 U.S. gal/hr) at 5200 RPM > >> cruise. > > > > 16 L/h corresponds to about 60% power with a 100 hp. > > Are you talking of *cruise* consumption, or overall consumption ? If you > > are doing much circuit work, low numbers are normal, since you are most > > of the time at part throttle. > > > > > > Best regards, > > -- > > Gilles > > http://contrails.free.fr > > > > > > ________________________________ Message 5 > _____________________________________ > > > > > > Time: 11:34:34 AM PST US > > Subject: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 > without a prop? > > From: "rparigoris" > > > > > > Hi Gilles > > "Yes monitoring the fuel pressure could add to the pilot's peace of mind, > > but it has no influence on the running of the engine. We monitor FF > > during takeoff." > > Lack of differential fuel pressure on take off leads to "running" of the > pilot > > when engine plays mellow song of "silent night". You need between ~ 2 and > 5 PSI > > differential. If low you could get proper fuel flow but on verge of not > being > > able to meet crack pressure of fuel pressure regulator. Problem is if you > have > > full float bowls and begin take off run, you will be in air with perhaps > not > > enough runway to land on when they run out. Also when cruising it gives > you > > a heads up to close at hand failure. Most culprits of low differential > pressure > > is clogged fuel filter or gasculator/s. If you reduce power and can > attain 2 > > PSI then you could probably gain yourself a little more time. At altitude > where > > the pumps have to work hardest are where you will first see lower > readings, > > a lower altitude may allow you to reach airport. Running lean at altitude > is > > a very bad thing to do, fuel flow may be fine at less than 2 PSI, but go > too much > > lower and fuel flow will suffer. Differential can give you a heads up to > problem > > before it happens. > > Ron Parigoris > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=294863#294863 > > > > > > ________________________________ Message 6 > _____________________________________ > > > > > > Time: 01:29:12 PM PST US > > Subject: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 > without a prop? > > From: "rparigoris" > > > > > > Heres someone else running without a prop. No question it revs quickly, > but not > > unlike many motorcycles: > > http://www.youtube.com/watch?v=tUrFJi93MIo > > Jason, is this you? > > Ron Parigoris > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=294872#294872 > > > > > > ________________________________ Message 7 > _____________________________________ > > > > > > Time: 03:15:57 PM PST US > > From: Guy Buchanan > > Subject: Re: RotaxEngines-List: 912s motor mount question > > > > > > At 09:59 AM 4/18/2010, you wrote: > >>I am still having a fight with the water pump being in the way. > > > > Being in the way of what? Can you provide pictures? (Please make them > small.) > > > > Thanks, > > > > > > Guy Buchanan > > San Diego, CA > > K-IV 1200 / 582-C / Warp / 400 hrs. and counting > > > > > > ________________________________ Message 8 > _____________________________________ > > > > > > Time: 03:52:16 PM PST US > > Subject: RotaxEngines-List: Re: Why exactly shouldn't you run a 914 > without a prop? > > From: "lucien" > > > > > > > > Float Flyr wrote: > >> Lucien: > >> > >> Dave has a video up on you tube where he hand props a 582 in the middle > of > >> winter up to his backside in snow. While rotax has good pull cord > starters > >> they have to come off to put on the standard electric starter. Being > able > >> to hand prop a plane can be literally a life saver on a cold Ontario > day. > >> > >> Noel > >> > >> -- > > > > > > Well, for sure if you need to be able to hand prop, no, you don't want to > install > > the clutch. And FWIW, the clutch does have some down sides so it's not a > one-size-fits-all > > addition. > > > > I've always flown pushers and so they weren't ever very safe to hand > start. But > > there was also room for the pull start too, so I wasn't in the situation > of say > > the Kitfox. But I'd usually carry a spare rope and some extra tools > enough > > to be able to do a field fix of a starter if the rope pulled out or > something > > like that. > > > > One time the handle pulled off the end of the rope on my quicksilver. > luckily there > > was already a knot in the rope a little further downstream so it didn't > suck > > the rope all the way into the housing. Whew... I tied another knot and > took > > off.... > > > > LS > > > > -------- > > LS > > Titan II SS > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=294894#294894 > > > > > > ________________________________ Message 9 > _____________________________________ > > > > > > Time: 07:06:20 PM PST US > > Subject: RotaxEngines-List: Desser 4.00-6 8 ply and 6 ply LSA tire > > From: "Roger Lee" > > > > > > Hi All, > > > > I had a nice and pleasant chat with a Desser supervisor today. After > installing > > these tires (4.00-6 8 ply) on a few of different aircraft here is what I > have > > found and discussed with Desser. First these tires do not come > pre-balanced and > > you will need to do that with some of the stick-on weights. It takes > about > > 1.25 oz. of weight to balance these. I used the 1/4 oz. weights. I put > some on > > the inside and out side of the wheel. No big sweat they balance right up > in a > > couple of minutes. > > Here is the big discussion. We started off with 30 psi on the 4.00-6 8 > plys. At > > 30 psi these tires seem to have a flat spot and were all bad tires. Not > so fast > > Hass! > > Talking to Desser these tires are not meant to run that low. The pressure > of 29 > > psi was for the original CT tires. They prefer to have at least 62 psi in > these > > tires if possible. That is little too much for us so we decided on 55-57 > psi > > and this took the so called flat spot out of the tire. These tires are > absolutely > > dependent on having enough psi to keep them nice and round. Even with > this > > if you hold a straight edge up to them they seem ever so slightly off. So > I > > went out and checked 3 other aircraft with other tires and found exactly > the > > same thing. No tire is 100% round and is dependent on the proper pressure > to maint > > that roundness. The less pressure under the recommended the worse it > became. > > It is the same for the 6 plys and other brands of tires from what I can > find. > > When you balance these tires and inflate them to 55 psi you will not have > > any issues with vibration. I check my 6.00-6 tires and others and they > were the > > same even though I didn't have to balance them. I am trying hard to get > Desser > > to pre-balance these tires like they do the larger tires and I believe we > have > > a good shot at this happening. I'll keep you informed as I do a little > more > > research for Desser and get some feed back. > > These seem to be good tires, but need proper inflation. How much psi are > the old > > Italian Mark Engegno wheels good for, I don't know. > > > > Like they used to say: > > Stay tuned and don't touch that dial! > > > > > > If your old you'll remember this saying and if you don't then you > probably don't > > remember Might Mouse either. [Laughing] > > > > -------- > > Roger Lee > > Tucson, Az. > > Light Sport Repairman - Maintenance Rated > > Rotax Repair Center > > 520-574-1080 > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=294919#294919 > > > > > > > > > > > > > > > > > > > > > > ________________________________ Message 5 _____________________________________ Time: 10:38:45 AM PST US From: Guy Buchanan Subject: Re: RotaxEngines-List: Re: RotaxEngines-List Digest: 9 Msgs - 04/19/10 At 05:16 AM 4/20/2010, you wrote: >My experience of declutched freewheeling propellers is that in event >of engine off, glide distance is significantly reduced, perhaps worse >than half. Relatively clean Kitfox IV-1200 at 1000# with a 70" Warp 3-blade free-wheeling and no flaps best glide ratio 9.6:1 at about 62 MCAS. With half flaps I get the same glide ratio at 52 MIAS. I know Lancair's can get up to 18:1, so I don't think the prop's reduced my glide ratio by half. I suspect the reduction is much reduced because my best glide speed is so slow. Or vice-versa. ;-) >Also the disturbed airflow over the tail can give you a nasty surprise >whe you try to do an accurate landing flare Never seen this on the Kitfox, where virtually every landing is "dead-stick" by virtue of the prop being disconnected from the engine near stall at idle. (Not so on descent. Normally the prop remains engaged just as it would on any other aircraft because you have to get the engine RPM down below 2500 to get it to disengage. That means getting it to disengage requires reducing speed to 40 MCAS, whereupon the prop disengages, and then increasing speed again with the prop disengaged.) I've never seen any kind of empennage control abnormality. (Seen plenty of pilot control abnormalities, though.) Guy Buchanan San Diego, CA K-IV 1200 / 582-C / Warp / 400 hrs. and counting ________________________________ Message 6 _____________________________________ Time: 02:40:21 PM PST US From: Gilles Thesee Subject: Re: RotaxEngines-List: Re: Fuel consumption for the 912S John Goodings a crit : > > My figure of 16 litres/hr (4.34 U.S. gal/hr) refers to takeoff at Carp > (near Ottawa), fly at 5200 RPM (about 80% power?) for 2 hours and land > at Orillia Lake St. John, and the reverse trip. The figure is lower > when many circuits are involved, as you suggest. In my experience, > Conti/Lycos (O-200A in particular) in C-150/C-152s were never as low > as this in fuel consumption. > John, To get an estimate of your power setting, RPM alone is not enough, you need additional info, such as manifold pressure. 16 L/h is the 75% manufacturer number for the 912 (5000 rpm/27.2"). For the 912S, Rotax gives a low 18,5 L/h @ 5000rpm/26". But the planes I flew burn something closer to 20 L/h with the 100 hp Rotax. The 100 hp C-150 also burns about 21 L/h at 75 % power, as does our 914. There is no mystery : if the mixture is correct, all engines burn about the same fuel at the same power setting. Best regards, -- Gilles http://contrails.free.fr ------------------------------------------------------------------------------------- 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.