---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Mon 11/30/09: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 0. 12:19 AM - [Please Read] - Last Official Day of List Fund Raiser! (Matt Dralle) 1. 06:51 AM - Re: 912 hoses and clamps (Catz631@aol.com) 2. 07:44 AM - Re: 912 hoses and clamps (rampil) 3. 08:16 AM - Re: 912 hoses and clamps (lucien) 4. 09:19 AM - Re: 912 hoses and clamps (rampil) 5. 09:51 AM - Re: Re: 912 hoses and clamps (Graham Singleton) 6. 10:14 AM - Re: 912 hoses and clamps (lucien) 7. 10:33 AM - Re: Re: 912 hoses and clamps (paul wilson) 8. 11:19 AM - Re: Re: 912 hoses and clamps (rparigor@suffolk.lib.ny.us) 9. 11:22 AM - Re: Re: 912 hoses and clamps (rparigor@suffolk.lib.ny.us) 10. 11:53 AM - Re: Re: 912 hoses and clamps (Paul McAllister) 11. 12:28 PM - Re: 912 hoses and clamps (rampil) ________________________________ Message 0 _____________________________________ Time: 12:19:26 AM PST US From: Matt Dralle Subject: RotaxEngines-List: [Please Read] - Last Official Day of List Fund Raiser! Dear Listers, Its November 30th and that means at least two things. For better or worse, its my 46th birthday! But it also means that its that last official day of the Matronics Email List Fund Raiser! If you been jones'n over one of the really nice gifts that are available this year with a qualifying Contribution, then now is the time to jump on one!! If you've been meaning to make a Contribution this month but have been putting it off for some reason, NOW is the time! I will be posting the List of Contributors in a few days, so you'll probably want to be known as a person that supported the Lists! I want to thank everyone that has so generously made a Contribution so far this year in support of our Lists. It is your generosity that keeps this operation a float and I don't ever forget it. Hopefully everyone feels the same. The List Contribution Web Site is fast and easy. Please support our habit by making your Contribution right now: http://www.matronics.com/contribution Thank you to all in advance! Matt Dralle Matronics Email List Administrator ________________________________ Message 1 _____________________________________ Time: 06:51:42 AM PST US From: Catz631@aol.com Subject: Re: RotaxEngines-List: 912 hoses and clamps Ron and LS thanks for the info !! It looks like McMaster is going to have the spring clamps I need and the price is much cheaper ! ( about $10 for a package of 25 vs $5 ea. at Rotax ! ) I saw a Rotax engine on a new Paradise the other day and it had the Constant-Tension spring band clamps. These look real nice also and provide a wider clamping area. I might go with that as the price is about the same but they might not apply as much clamping pressure. Looks like it's Rotax hose though as combing thru the additional websites only gave me sae sizes and no metric. Thanks for all your help ! Dick Maddux Milton,Fl ________________________________ Message 2 _____________________________________ Time: 07:44:55 AM PST US Subject: RotaxEngines-List: Re: 912 hoses and clamps From: "rampil" Dick, A couple of points. Any heater hose will work, silicone is nice, reinforced is nice but way above spec. Remember, the coolant cap pops off at 1.2 bar. Why would you want 10 or 50 bar reinforced hose?? Personally I think flexibility is paramount 16 mm fits fine if it is silicone. I don't know if nomex will hand stretch to 17. All polymer hose (including rubber and plastics) should be firesleeved fire-wall forward. Per AC43! The wire clips are not better from an engineering standpoint than stainless wormgear standard clamps. At Oshkosh and SnF, there is a vendor who sells a tool that lets you make your own (non springy) wire clamps. I asked Dean (at Lockwood) about it last year, He said he has one and will on occassion use it. Good Luck! Ira -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=275492#275492 ________________________________ Message 3 _____________________________________ Time: 08:16:11 AM PST US Subject: RotaxEngines-List: Re: 912 hoses and clamps From: "lucien" rampil wrote: > Dick, > > A couple of points. > Any heater hose will work, silicone is nice, reinforced is nice but > way above spec. Remember, the coolant cap pops off at 1.2 bar. > Why would you want 10 or 50 bar reinforced hose?? Personally > I think flexibility is paramount > > 16 mm fits fine if it is silicone. I don't know if nomex will hand stretch to 17. > > All polymer hose (including rubber and plastics) should be firesleeved fire-wall forward. Per AC43! > > The wire clips are not better from an engineering standpoint than stainless > wormgear standard clamps. > > At Oshkosh and SnF, there is a vendor who sells a tool that lets you > make your own (non springy) wire clamps. I asked Dean (at Lockwood) > about it last year, He said he has one and will on occassion use it. > > > Good Luck! > > Ira Not really meaning to be pedantic here, but ... ;) The installation manual for the 912 series is very specific about the requirements for the cooling hose (section 12.6 for quick reference). A minimum of 5 bar (73 psi) pressure durability is required and of course that's a minimum. So if it meets that as well as the temperature and fluids requirements, you should be good to go. Also, I personally would accept any suitable substitute on the hose _except_ the wrong size hose. Too small of a hose puts more than design stress on the hose where it goes over the fitting and this eventually increases the risk of cracking and failure in this area. Skimping here for a few bucks on the hose could cost upwards of 20 large or higher later on, so this is a good area to not disobey ;) Don't ask me why I know this. LS -------- LS Titan II SS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=275500#275500 ________________________________ Message 4 _____________________________________ Time: 09:19:34 AM PST US Subject: RotaxEngines-List: Re: 912 hoses and clamps From: "rampil" Lucien, Some hoses are engineered to stretch over hose barb fittings, in fact thats how barbs work. Other hoses are not. For example, I would like to convert my fuel system to Aeroquip 666 teflon/carbon hose. This stuff does not stretch at all within the limits of human strength, so it can not go over rotax standard hose barbs and I do not feel like converting all the fitting to NAS. Silicone hose on the other hand is designed to stretch and 16 instead of 17 mm is only 5% expansion. The barb rings are probably more than 5% As for burst strength. I said heater hose which is all a couple of bar. I was the expensive reinforced hose I was commenting on as not a useful use of funds. If the pressure anywhere in the system goes to 10 bar, due to an obstruction and not reaching the cap, then flow and cooling is blocked, just as bad as loss of coolant. PS, a 900 series engine will run for 30 min or more with no coolant. A 900 series engine will run for 1 minute or less with no oil before serious damage according to many sources. Spend your money on good oil hose! -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=275512#275512 ________________________________ Message 5 _____________________________________ Time: 09:51:04 AM PST US From: Graham Singleton Subject: Re: RotaxEngines-List: Re: 912 hoses and clamps Ira I thought spring clips were preferred (by Rotax) because when the polymer hose relaxes with heat it reduces the clip pressure and a spring takes up most of the slack, whereas a worm drive clip doesn't until chastised with a screw driver? Be interested in the vendor you mention? Graham rampil wrote: > The wire clips are not better from an engineering standpoint than stainless > wormgear standard clamps. > > At Oshkosh and SnF, there is a vendor who sells a tool that lets you > make your own (non springy) wire clamps. I asked Dean (at Lockwood) > about it last year, He said he has one and will on occassion use it. > > Ira > > ________________________________ Message 6 _____________________________________ Time: 10:14:59 AM PST US Subject: RotaxEngines-List: Re: 912 hoses and clamps From: "lucien" rampil wrote: > Lucien, > > Some hoses are engineered to stretch over hose barb fittings, > in fact thats how barbs work. Other hoses are not. > > For example, I would like to convert my fuel system to Aeroquip 666 > teflon/carbon hose. This stuff does not stretch at all within the limits of > human strength, so it can not go over rotax standard hose barbs and I > do not feel like converting all the fitting to NAS. > > Silicone hose on the other hand is designed to stretch and 16 instead of > 17 mm is only 5% expansion. The barb rings are probably more than 5% > > As for burst strength. I said heater hose which is all a couple of bar. > I was the expensive reinforced hose I was commenting on as not a > useful use of funds. If the pressure anywhere in the system goes to 10 > bar, due to an obstruction and not reaching the cap, then flow and > cooling is blocked, just as bad as loss of coolant. > All I'm saying is I like to use the right equipment and acceptable substitutes wherever possible, even if it means spending a little extra money. If you use the wrong size hose, well, it's your engine. I simply prefer not to take extra risks like that when there's a way to not have to take them. My 912 also has the non-FAR 33/ASTM fittings on the oil tank and carburettors and I also have forgone upgrading the fittings to use the aeroquip line. I use tygothane line and small worm clamps for the fuel as well as push-on oil lines for the oil. That's acceptable to me, tho, because I'm accustomed to using the stuff and have for 10 years with no problems. You do have to change the lines out about every 2 years, but that's not too hard to do on my plane. But just for me personally, I draw the line at using the wrong size hose on engine/flight/life critical parts like coolant hoses. But that's just me. YMMV. > > PS, a 900 series engine will run for 30 min or more with no coolant. > A 900 series engine will run for 1 minute or less with no oil before > serious damage according to many sources. Spend your money on > good oil hose! Is the engine reusable after that 30 mins tho? I've always been curious about that, tho I'd assume not. So I try to use the right hoses for both oil and coolant.... but thats just me like I said... LS -------- LS Titan II SS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=275524#275524 ________________________________ Message 7 _____________________________________ Time: 10:33:54 AM PST US From: paul wilson Subject: Re: RotaxEngines-List: Re: 912 hoses and clamps OEM cars/trucks use the spring type which are properly called constant force clamps. and you are correct, they keep a constant force on the hose to compensate for the relaxation of the elastomer/rubber hoses. Change the hose from the OEM product then the constant force clamps must change accordingly to match the new hose. Thus we all use the worm gear equal design and tighten them occasionally. Barbed fittings grab the hose and removal almost always destroys the hose. This is why OEM auto people use beaded ends instead of barb. All the hose connections on my plane and my off road truck use beaded tube ends at the hose attachment. I also use fuel injection clamps instead of the worm gear clamps because they are rated an higher pressure than the worm gear ones. Go to any auto store and compare them to what you are using. Paul ============== At 09:38 AM 11/30/2009, you wrote: > > >Ira >I thought spring clips were preferred (by Rotax) because when the >polymer hose relaxes with heat it reduces the clip pressure and a >spring takes up most of the slack, whereas a worm drive clip doesn't >until chastised with a screw driver? >Be interested in the vendor you mention? >Graham > >rampil wrote: >>The wire clips are not better from an engineering standpoint than stainless >>wormgear standard clamps. >> >>At Oshkosh and SnF, there is a vendor who sells a tool that lets you >>make your own (non springy) wire clamps. I asked Dean (at Lockwood) >>about it last year, He said he has one and will on occassion use it. >> >>Ira >> >> > > ________________________________ Message 8 _____________________________________ Time: 11:19:16 AM PST US Subject: Re: RotaxEngines-List: Re: 912 hoses and clamps From: rparigor@suffolk.lib.ny.us Hi Graham > I thought spring clips were preferred (by Rotax) because when the > polymer hose relaxes with heat it reduces the clip pressure and a spring > takes up most of the slack, whereas a worm drive clip doesn't until > chastised with a screw driver? **Think you are spot on. Then after a while of tightening to stop leaks you end up ruining the hose as you mash it up, don't have to tell you that. > Be interested in the vendor you mention? **www.mcmaster.com sells them, they call them ear hose clamps: http://www.mcmaster.com/#ear-hose-clamps/=4qbq5c Don;'t quite remember but Okita, Ortega something close to this is one mfg. one neat clamp that auro high performance places sell is pretty much a removable version of these clamps, you ratchet spring them together with a pair of pliers, and can remove them by pushing sideways. i don't know mfg. name, but SK or SKF Speed stores sell them in New York. Ron Parigoris ________________________________ Message 9 _____________________________________ Time: 11:22:37 AM PST US Subject: Re: RotaxEngines-List: Re: 912 hoses and clamps From: rparigor@suffolk.lib.ny.us Hi Ira " PS, a 900 series engine will run for 30 min or more with no coolant." Not completly true, A 900 engine will cease to run almost immediate if it injests steam from a failed hose. Itcan come back to life just at the wrong moment. Ron Parigoris ________________________________ Message 10 ____________________________________ Time: 11:53:04 AM PST US From: Paul McAllister Subject: Re: RotaxEngines-List: Re: 912 hoses and clamps Hi All, I thought that Rotax changed to CTC clamps, in part as a response to the formal report on Graham's accident. My engine that was delivered in 2003 had them fitted, however, I just had some work done at Rotax service center and they used screw clamps and the hose was branded "Gates Heater Hose". I am going changing over to silicon hoses and CTC clamps for the water pump because last winter it leaked due to thermal contraction. Mind you winters in the Mid West are pretty darn cold and last year particularly so. Cheers, Paul ________________________________ From: Graham Singleton Sent: Mon, November 30, 2009 11:38:56 AM Subject: Re: RotaxEngines-List: Re: 912 hoses and clamps Ira I thought spring clips were preferred (by Rotax) because when the polymer hose relaxes with heat it reduces the clip pressure and a spring takes up most of the slack, whereas a worm drive clip doesn't until chastised with a screw driver? Be interested in the vendor you mention? Graham rampil wrote: > The wire clips are not better from an engineering standpoint than stainless > wormgear standard clamps. > > At Oshkosh and SnF, there is a vendor who sells a tool that lets you > make your own (non springy) wire clamps. I asked Dean (at Lockwood) > about it last year, He said he has one and will on occassion use it. > > Ira > > ________________________________ Message 11 ____________________________________ Time: 12:28:38 PM PST US Subject: RotaxEngines-List: Re: 912 hoses and clamps From: "rampil" Its a wonderful thing to see experimental aircraft actually being used experimentally like the FAA intended!! :-) My own choices of hose for my recent 5 year annual was Gate R7 stainless braided hose for engine compartment, Gates R7 no braid aft of Firewall for fuel. The R7 spec is the Fuel injection grade, replacing the low pressure R5 hose with the original kit. The hose is also rated for longer service life. For Oil hose I used the relatively new Aeroquip FC332 (blue) socketless hose for oil lines. Coolant hose is also Gates. All firesleeved. Spring clips are or should be speced to the hose used. To see if CTC is indicated in an application, one needs to check the specific hose for the coefficients of expansion with heat and swelling with solvent absorption. I suppose this is part of what they call "Rocket Science," Anyway, we are free (in the US anyway) to try different hoses and report our results. So far, nothing to report in six months of service. -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=275545#275545 ------------------------------------------------------------------------------------- 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.