---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Mon 10/25/10: 17 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:38 AM - Re: Re: Washed gas technical considerations (Noel Loveys) 2. 06:51 AM - Re: Re: 100ll 100% of the time (Noel Loveys) 3. 06:56 AM - Re: Re: Washed gas technical considerations (Noel Loveys) 4. 08:03 AM - Re: Re: Rough runing above idle. (Hugh McKay) 5. 08:03 AM - Re: Re: Rough runing above idle. (Joel M.) 6. 09:30 AM - Re: Re: Rough runing above idle. (Ken Ryan) 7. 09:45 AM - Re: Re: Rough runing above idle. (Pete Christensen) 8. 02:16 PM - Re: Washed gas technical considerations (sdemeyer) 9. 03:22 PM - Let's get our act TOGETHER! (FLYaDIVE) 10. 03:37 PM - Re: Re: Washing Ethanol out of Gas (FLYaDIVE) 11. 03:37 PM - Re: Let's get our act TOGETHER! (Pete Christensen) 12. 04:06 PM - Re: Washing Ethanol out of Gas (Roger Lee) 13. 04:15 PM - Spot 2 tracker (Roger Lee) 14. 05:00 PM - Re: Re: Washing Ethanol out of Gas (bjones@dmv.com) 15. 05:19 PM - Follow me on Spot tomorrow to Yuma, AZ (Roger Lee) 16. 07:03 PM - Re: Re: 100ll 100% of the time (Noel Loveys) 17. 08:37 PM - Re: Re: Washing Ethanol out of Gas (Noel Loveys) ________________________________ Message 1 _____________________________________ Time: 06:38:40 AM PST US From: "Noel Loveys" Subject: RE: RotaxEngines-List: Re: Washed gas technical considerations And now a word about using leaded fuel in two stroke engines... Rotax or otherwise. The process that a two stroke engine uses is to draw the fuel mixture into the base of the engine then to push it into the open ported piston when the piston is close to bottom. This push of air fuel pushes exhaust gasses out. The problem with this is if we are using leaded fuel the fuel/oil mixture coats the bearings of the engine which unlike four stroke engines are roller type bearings. The mixture is subjected to some pressure in the bearings and this can cause some of the lead in the fuel to plate out on either the bearing surfaces or the race. Get enough lead on the bearings and it will fail. Will this happen by using leaded fuel for an hour or two? No but it certainly can happen with extended use. Lowering the concentration of lead in the fuel by mixing a bit of 100LL with unleaded gas, washed or otherwise will obviously lessen the plating process. If I were to use it in a two stroke engine I'd shorten the TBO to perhaps 300 hr.. This is because the crank has to come out to inspect the condition of the bearings. As much as I hate the idea of flying on ethanol contaminated fuels I think I would still prefer to do that rather than use leaded fuel. If I were to use gasohol I would take certain precautions. Like never leaving fuel in the plane, always using fresh fuel, and draining the tanks if I thought the plane may not be flown for several days, especially if they were rainy days. As for washing the gas by all means for use in an engine that only requires low octane fuel. Higher compression engines which require higher octane fuel will have to find a good, emphasis on the word, "good", octane booster. So far I haven't found one that actually works. None of the boosters I've seen will actually give the octane rating of the booster itself so a person can decide how much to use to increase their fuel to the required octane. Noel -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of bjones@dmv.com Sent: October 24, 2010 12:16 AM Subject: Re: RotaxEngines-List: Re: Washed gas technical considerations We may be missing important differences between Rotax 912 4-stroke engines and Rotax 2-strokes. The 4-strokes risk lead plating out of the crancase oil. Rotax 2 - strokes do not have crancase oil and therefor are different beasts. In Rotax 4 - strokes, lead plating occurs because our Rotax approved 4-stroke crankcase oils do not suspend lead that blows by the piston to cylinder interface nearly as well as conventional ashless dispersent aviation oils, which are not recommened for Rotax 4 - strokes. With this difference in mind, for the 4-stroke 912s, Consider washed gas with about 30 percent 100 LL added plus 25 hour oil changes. These two protocols should do 2 things. One is prevent significant lead plating. Second is, insure adequate octane for the 100 hp Rotax. Read more details below. AMOCO engineers working with the EAA on thier auto gas STCs for General Aviation engines years ago, reported that even 30 percent 100 LL, when mixed with 70 percent high octane unleaded auto gas would boost the octane of the auto gas enough to provide an octane rating much higher than the base auto gas and make octane no problem in high compression ratio mid-1960s Corvettes and other muscle car engines as well as the Lycoming in my normally aspirated Mooney. At 30 percent 100 LL, The large amount of lead in the 100 LL should return the 2 - 3 octane points lost washing premium auto gas so that 100 hp Rotax engines are happy. If anyone knows better, please chime in. This may be important to the 15 percent ethanol discussion. As an aside, the premium auto gas was bad for the wet wing gas tank sealant in the Mooney, accelerating weapage and requiring resealing which Mooney wet wing tanks were notorious for under the best of circumstances. The 25 hour oil changes in the 912s may also be valuable so that the small amount of lead that blows by the 4-stroke Rotax rings is carried out by our Rotax approved oils. Longer oil change intervals may overcome the oils capacity to suspend lead. Keep in mind that 912s have very little blow by compared to big bore aircooled general aviation aircraft engines which use 100 LL exclusively. It may be wise to Avoid fully synthetic oils in 912s when using a fuel mix with 100 LL, unless they have ashless dispersant qualities. Fully synthetic oils typically hold very little lead in suspension. Unlike our Rotax 912s, big aircooled aviation engines require Aviation grade ashless dispercent oils which hold lots of lead in suspension. This is necessary because Continentals and Lycomings have very wide piston to cylinder tolerances allowing lots of lead blow by compared to 912s. Many will remember that Fully synthetic Mobil 1 caused engine failures because it did not keep lead in suspension, ruining engines. Fully synthetic Mobil 1 was pulled from aviation use because of this. By the way, in addition to the different considerations between 4-stroke and 2-stroke engines in terms of 100 LL use, my Kitfox has FIBERGLASS TANKS THAT ARE NOT ETHANOL RESISTANT, so washing premium auto gas and adding 30 percent 100 LL seems like a logical alternative. I get plenty of octance and my fuel filters are not clogged by deteriorating fiberglass from the effect of ethanol on the gas tanks. I hope others weigh in on these comments, maybe with more current technical knowledge. BJ N154K Kitfox IV 80 hp Rotax N626NR PA 39 Turbocharged Twin Comanche > > > Ok, then what should we do? Use 15% ethanol, use 100ll 50% of the time, > and > 15% ethanol 50% of time .... my personal hope is that 100ll goes away as > soon as possible and whatever substitute is made available will be better > for the 912...high enough octane, no lead...a dream proabably...it won't > happen until long after I am dead.....I really don't know what to > do...'washing' ethanol-laced fuel doesn't appeal to me and ethanol-free > auto > gas is no longer available in my area. > > Your suggestion? > > > ----- Original Message ----- > From: "Roger Lee" > To: > Sent: Saturday, October 23, 2010 4:33 PM > Subject: RotaxEngines-List: Re: 100ll 100% of the time > > >> >> >> Hi John, >> >> Sounds like you have a good handle on the use of 100LL. >> Buuuttt, If you have seen any pictures or a leaded engine or have seen >> the engine top ends and gearbox's I have you wouldn't use 100LL unless >> forced to during travel. When you see the lead paste build up in the oil >> tank you will need to de-lead the gearbox at 800 hours not 1000 hrs. and >> send the gearbox clutch in to have the lead removed or else it won't >> properly work any more, or if you had seen the lead on top of the >> pistons >> and around the valves you may want to reconsider if you can. Rotax >> advises >> to use 91 Oct and stay away from 100LL if at all possible. We just gave >> a >> class and some pictures were shown to the students of the lead deposits. >> I >> think it made believers out of them. >> >> -------- >> 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=316798#316798 >> >> >> >> >> >> >> >> >> >> > > ________________________________ Message 2 _____________________________________ Time: 06:51:27 AM PST US From: "Noel Loveys" Subject: RE: RotaxEngines-List: Re: 100ll 100% of the time The Rotax engine itself is certified by Rotax to operate on up to 10% ethanol. It is all the other parts of the fuel system that you can expect to have problems with. You said there have been no problems with cars, motorcycles etc. I have to call you on that one. They have had many problems with the introduction of ethanol. Sludge in the engine comes free and gums up the works. If there is any moisture in the fuel it will eat the aluminium gas lines and carburettors. Any guesses what it does to diaphragm pumps? You mentioned kreeming the fuel tanks. A few years ago an aviation list had a long discussion in Kreeme coming off the inside of tanks... Talk about a mess. The problem as I see it is all these coatings say ethanol resistant. Not one of them will tell me at least exactly what they mean when they say resistant. There can be a world separating resistant and proof. Finally all that aside there is still the possibility of a phase separation. Some say it will never happen. I say never is a long time. I guess if you happen to live in death valley that will be a very small possibility but if you live in a very humid climate as I do then you can expect that any ethanol fuel you purchase will have already absorbed some level of moisture. The ethanol fuel itself absorbs so much moisture that all the gas in the distribution facility is ethanol free. Ethanol is only added to the gas when it is put in the truck directly prior to delivery to your service station. For that reason I always recommend to people that they use only fresh, from a very busy station fuel and not leave it in the plane for extended periods of time. Noel -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Roger Lee Sent: October 24, 2010 1:04 AM Subject: RotaxEngines-List: Re: 100ll 100% of the time Hi John, I have to ask why not use the auto fuel? If you were going to mix 100LL with Auto fuel then you might as well use all auto fuel. The ethanol will not hurt the Rotax engine so that shouldn't even be one of your concerns. Most all fuel lines now days can handle ethanol or we would have all sorts of problems in our cars and motorcycles. So that leaves pretty much just the fuel tank. Make sure it is ok with our 6%-8% ethanol that is found at most pumps and just use the auto fuel. If there is absolutely no way you can use the auto fuel and you are stuck with 100LL then you need to resign yourself that you will and must do so extra maint. The lead in 100LL is like smoking or cholesterol and fats in our blood. It doesn't kill you or give you a heart attack today. It builds up over time until it's too late. There is no ethanol free fuel in my area either. I have been using it for many years as others have here. People in the rest of the world use anywhere from 17%-24% ethanol in their Rotax and have no issues. People who worry about ethanol in their Rotax 912 are worrying over nothing. Just take a look at the rest of the fuel system and if it's ok your set to go. You can Kreem Weiss your tanks and that is not susceptible to the ethanol. My tanks and all the aircraft like mine and other LSA have their tanks coated with Kreem Weiss. It's good for sealing any kind of leaks, too. Personally if I had wing tanks I would just coat them and don't look back. Decalin, a lead scavenger will only do so much, but it does help. You still have lead build up. If you use Decalin and 100LL you need to run higher rpm at cruise (5300) to help keep the lead blown out. If you cruise around 4700-5000 rpm you are not doing what needs to be done to help keep the engine clean. Anyone who thinks 100LL with Decalin doesn't allow lead build up has never seen an 800 hr. engine or gearbox torn down. Sure it will run, but what you don't see is harmful, just like the cholesterol. Just because you can't see it and your engine hasn't given you any issues yet doesn't mean it isn't there. >From what I have seen most peoples weakest link is the fuel tank with the ethanol. Dan, If the guy you are talking about with 800 hrs. has been using all 100LL for all those hours he really should pull the gearbox and have the slipper clutch dismantled and cleaned. Once the lead gets in there it isn't working any more. It is just a solid piece of metal and if he has a prop strike it won't work. When he has hard starts or shut downs it is harder on the system, too. We just got through showing a bunch of people in a class pictures of gearbox clutches with 100LL use. They were amazed at how much lead really was in them. Pulled the heads and showed them all the lead there, too. -------- 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=316829#316829 ________________________________ Message 3 _____________________________________ Time: 06:56:31 AM PST US From: "Noel Loveys" Subject: RE: RotaxEngines-List: Re: Washed gas technical considerations A 50:50 blend of 88 RON mixed with 100LL will produce 94 octane fuel. To raise 88 RON to 91 RON will require a mix of around 70:30. Noel -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Roger Lee Sent: October 24, 2010 1:26 AM Subject: RotaxEngines-List: Re: Washed gas technical considerations Hi B Jones, If you wash your fuel and drop the octane to 88 then you will need to use at least a 50/50 mix of auto fuel and 100LL to get you safely back to the 91-92 octane. This is what Rotax calls for when using 87 Octane Mogas. No less than a 50/50 blend. You are correct about not using a full synthetic oil because it will not suspend lead. If you are going to use 100LL all the time at any percent use a semi synthetic oil i.e. Aero Shell Sport Plus 4 or Golden Spectro 4 and they absolutely do need to be motorcycle oils. Car oils do not have the additives for our engine / gearbox system. Our engines are like our motorcycles and the engine and gearbox oil is the same. The car oils can not handle the "shear" issues with our gearbox. -------- 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=316830#316830 ________________________________ Message 4 _____________________________________ Time: 08:03:50 AM PST US From: "Hugh McKay" Subject: Re: RotaxEngines-List: Re: Rough runing above idle. Tucsonchris, I don't know much about the Kitfox airplane or the company, but if they would fabricate aluminum tanks, that would seem to solve the problem. Hugh McKay Allegro 2000 Rotax 912 UL -------------------------------------------------- From: "Tucsonchris" Sent: Monday, October 25, 2010 1:03 AM Subject: RotaxEngines-List: Re: Rough runing above idle. > > > Problem solved-- > > My tanks were dissolving. These are the newest alcohol resistant tanks > from Kitfox, BTW, so obviously nothing is truly alcohol resistant any > more. My only solution is 100 LL--while it lasts. thanks for all the > feedback. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=316931#316931 > > > ________________________________ Message 5 _____________________________________ Time: 08:03:50 AM PST US From: "Joel M." Subject: Re: RotaxEngines-List: Re: Rough runing above idle. Fiberglass tanks have to be coated with an ethanol resistant two part epoxy fuel tank coating system when they are built.- This has been working wel l and makes fiberglass tanks just as good as anything else.- Stay away fr om 100LL at all cost. Joel --- On Sun, 10/24/10, Tucsonchris wrote: From: Tucsonchris Subject: RotaxEngines-List: Re: Rough runing above idle. t> Problem solved-- My tanks were dissolving. These are the newest alcohol resistant tanks from Kitfox, BTW, so obviously nothing is truly alcohol resistant any more. My only solution is 100 LL--while it lasts. thanks for all the feedback. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=316931#316931 le, List Admin. ________________________________ Message 6 _____________________________________ Time: 09:30:47 AM PST US Subject: Re: RotaxEngines-List: Re: Rough runing above idle. From: Ken Ryan Would there be any reason to coat aluminum tanks? On Mon, Oct 25, 2010 at 6:57 AM, Joel M. wrote: > Fiberglass tanks have to be coated with an ethanol resistant two part epoxy > fuel tank coating system when they are built. This has been working well > and makes fiberglass tanks just as good as anything else. Stay away from > 100LL at all cost. > Joel > > --- On *Sun, 10/24/10, Tucsonchris * wrote: > > > From: Tucsonchris > Subject: RotaxEngines-List: Re: Rough runing above idle. > To: rotaxengines-list@matronics.com > Date: Sunday, October 24, 2010, 11:03 PM > > gallchrisa@qwest.net > > > Problem solved-- > > My tanks were dissolving. These are the newest alcohol resistant tanks from > Kitfox, BTW, so obviously nothing is truly alcohol resistant any more. My > only solution is 100 LL--while it lasts. thanks for all the feedback. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=316931#316931 > Navigator?RotaxEngines-List" target="_blank"> > http://www.matronics.com/Navigator?RotaxEngines-List --> > > > > > * > > * > > ________________________________ Message 7 _____________________________________ Time: 09:45:54 AM PST US From: Pete Christensen Subject: Re: RotaxEngines-List: Re: Rough runing above idle. Ethanol will corrode aluminum. Pete On 10/25/2010 11:27 AM, Ken Ryan wrote: > Would there be any reason to coat aluminum tanks? > > > On Mon, Oct 25, 2010 at 6:57 AM, Joel M. > wrote: > > Fiberglass tanks have to be coated with an ethanol resistant two > part epoxy fuel tank coating system when they are built. This has > been working well and makes fiberglass tanks just as good as > anything else. Stay away from 100LL at all cost. > Joel > > --- On *Sun, 10/24/10, Tucsonchris / >/* wrote: > > > From: Tucsonchris > > Subject: RotaxEngines-List: Re: Rough runing above idle. > To: rotaxengines-list@matronics.com > > Date: Sunday, October 24, 2010, 11:03 PM > > > > > Problem solved-- > > My tanks were dissolving. These are the newest alcohol > resistant tanks from Kitfox, BTW, so obviously nothing is > truly alcohol resistant any more. My only solution is 100 > LL--while it lasts. thanks for all the feedback. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=316931#316931 > Navigator?RotaxEngines-List" > target="_blank">http://www.matronics.com/Navigator?RotaxEngines-List --> > > > > > * > > ist" target="_blank">http://www.matronics.com/Navigator?RotaxEngines-List > tp://forums.matronics.com > _blank">http://www.matronics.com/contribution > > * > > > * > > > * ________________________________ Message 8 _____________________________________ Time: 02:16:37 PM PST US Subject: RotaxEngines-List: Re: Washed gas technical considerations From: "sdemeyer" The focus seems to be whether or not Rotax engines will run fine on ethanol laced fuel. I agree that the engine itself is happy with this fuel. The problem is the rest of the fuel system is not happy. I had a Kitfox tank disintegrate from Ethanol laced fuel. The seams literally melted apart. This happened to me while I was flying. Having fuel running all over you at 1,000 feet is not fun in the least bit. Fortunately I can get uncontaminated fuel from a local Indian Reservation. If no uncontaminated auto fuel was available I would use 100LL with Decalin. Scott Read this topic online here: http://forums.matronics.com/viewtopic.php?p=317017#317017 ________________________________ Message 9 _____________________________________ Time: 03:22:19 PM PST US Subject: RotaxEngines-List: Let's get our act TOGETHER! From: FLYaDIVE Awe, come on guys... It's not rocket science... It's not brain surgery... It's not even aviation... It's not difficult! Let's Keep The Threads Together. PLEASE! Open and respond to a thread in the SAME email. Have you LQQK'd at ALL the Same Subjects that are scatted through out the message board. It makes following them and keeping a timeline difficult. More difficult than flying an ILS in a crosswind. Form up on Lead in Right echelon. Thank you guys. Barry PS I'm an old fart and I don't have much time left on the earth. I don't want to squander it away trying to untangle an email. ;-) ________________________________ Message 10 ____________________________________ Time: 03:37:55 PM PST US Subject: Re: RotaxEngines-List: Re: Washing Ethanol out of Gas From: FLYaDIVE Roger: Interesting on this subject of gas. How was the 88.3 Octane level determined? Barry On Sat, Oct 23, 2010 at 6:42 PM, dave wrote: > > > Roger Lee wrote: > > Hi All, > > > > If you all are washing gas for the 912ULS 100 hp then you should stop and > I wouldn't put another drop of washed fuel in my 912ULS. I just got with > some people that work with this as a business and did some real testing at a > lab. The washed gas looses octane and the 91 oct. went from 91 to 88.3 oct. > It also took out some of the additives. That 88.3 Oct. is too low for the > 912ULS 100 hp. You will eventually ruin your engine. For the guys with the > 912UL 80 hp you could still use this fuel at 88 oct. > > I just saw the lab results a few hours ago. These guys really did their > homework. > > If you want to use this technique there are devices on the market. > > > Roger I just passed 1100 hours in Rotax 2strokes with Ethanol gas. > > is there a proble with ethanol gas ? > > The ones that whine about it -heck might not fly much ? > > Armchair captains > > Check my videos -- Real time proof it works . > > I am not a supporter of ethanol gas but it here and I ain't got no choice. > SO I MAKE IT WORK > > -------- > Rotax Dealer, Ontario Canada > http://www.cfisher.com/ > Awesome *New Forum * > http://rotaxaircraft.com/forum/ > Realtime Kitfox movies to separate the internet chatter from the truth > http://www.youtube.com/profile_videos?user=kitfoxflyer > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=316801#316801 > > -- Barry "Chop'd Liver" ________________________________ Message 11 ____________________________________ Time: 03:37:55 PM PST US From: Pete Christensen Subject: Re: RotaxEngines-List: Let's get our act TOGETHER! I agree Barry but tell us how you feel about ethanol first. ;>) Pete On 10/25/2010 5:15 PM, FLYaDIVE wrote: > Awe, come on guys... > > It's not rocket science... > It's not brain surgery... > It's not even aviation... > It's not difficult! > > Let's Keep The Threads Together. > > PLEASE! Open and respond to a thread in the SAME email. > > Have you LQQK'd at ALL the Same Subjects that are scatted through out > the message board. > > It makes following them and keeping a timeline difficult. > More difficult than flying an ILS in a crosswind. > > Form up on Lead in Right echelon. > > Thank you guys. > > Barry > > PS > I'm an old fart and I don't have much time left on the earth. I don't > want to squander it away trying to untangle an email. > > ;-) > > > * > > > * ________________________________ Message 12 ____________________________________ Time: 04:06:13 PM PST US Subject: RotaxEngines-List: Re: Washing Ethanol out of Gas From: "Roger Lee" Hi Barry, The fuel was tested at a lab before washing and the same fuel tested after washing. I don't know the exact method the lab used to define the octane rating. The first sample of the untreated fuel was right on and the washed fuel test results looked right in line with what you would expect. -------- 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=317024#317024 ________________________________ Message 13 ____________________________________ Time: 04:15:29 PM PST US Subject: RotaxEngines-List: Spot 2 tracker From: "Roger Lee" Hi All, I'm getting together another group that wants Spot 2 Trackers. They are great. Check out their website. I usually buy them by the case and I'm getting ready to order a few more cases. I sell them for cost plus my shipping as a safety public service. If you want one email me. here is a sample Spot Track from a friend of mine that just flew from Phoenix, AZ to Mexico. This does several things other than just track and can be used for hunting, hiking, quad riding, motorcycle riding, fishing, just about anything. Read about it it is just what the doctor ordered for safety. You need to contact me off list for a price. http://share.findmespot.com/shared/faces/viewspots.jsp?&glId=0SVfqeSZBl3yVkQ7mSqU5SLTyL2kyct1m -------- 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=317026#317026 ________________________________ Message 14 ____________________________________ Time: 05:00:16 PM PST US Subject: Re: RotaxEngines-List: Re: Washing Ethanol out of Gas From: bjones@dmv.com Regarding 912 Rotax 4 - stroke, The 2 to 3 point octane loss seems to be what multiple folks in the proprietary gasoline additive aftermarket business have seen in their testing. I also heard that figure from one of the major aftermarket additives companies two or three years ago while talking with thier fuel additive engineers. Amoco gas engineers working with the EAA on unleaded gas STCs for GA engines were adamant that a little bit of lead from a small percentage of 100 LL (25%) mixed with unleaded auto fuel resulted in a very prominent increase in octane and that additional increases in octane required relatively dramatic increases in lead. In other words the increase in octane with increase in lead content is not a straight line but an upswept curve. 25 to 30 percent 100 LL seemed to provide enough lead to gain back about 3 octane points according to what I remember and 50 % 100 LL seems to be what others are hearing is required to regain octane lost thru washing. If Shell included some ashless dispersant qualities in thier new 4 - stroke light sport aviation oil, plating out of lead may not be a big issue if 25 hour oil changes are carried out. I have to think that Shell at least tested some ashless dispersant qualities for thier new 4 - stroke Light Sport aviation oil, because Shell knows the fleet is predominantly Rotax 912s, that 100 LL use will be common in these engines, and Shell engineers certainly have lots of expertise in ashless dispersant technology for aviation oils. If anyone knows the lead suspension qualities of Shells 4- stroke light sport oil, fill us in. BJ Kitfox IV, 912 N154K Twin Comanche PA 39 N626NR Roger: > > Interesting on this subject of gas. How was the 88.3 Octane level > determined? > > Barry > > On Sat, Oct 23, 2010 at 6:42 PM, dave wrote: > >> >> >> Roger Lee wrote: >> > Hi All, >> > >> > If you all are washing gas for the 912ULS 100 hp then you should stop >> and >> I wouldn't put another drop of washed fuel in my 912ULS. I just got with >> some people that work with this as a business and did some real testing >> at a >> lab. The washed gas looses octane and the 91 oct. went from 91 to 88.3 >> oct. >> It also took out some of the additives. That 88.3 Oct. is too low for >> the >> 912ULS 100 hp. You will eventually ruin your engine. For the guys with >> the >> 912UL 80 hp you could still use this fuel at 88 oct. >> > I just saw the lab results a few hours ago. These guys really did >> their >> homework. >> > If you want to use this technique there are devices on the market. >> >> >> >> >> Roger I just passed 1100 hours in Rotax 2strokes with Ethanol gas. >> >> is there a proble with ethanol gas ? >> >> The ones that whine about it -heck might not fly much ? >> >> Armchair captains >> >> Check my videos -- Real time proof it works . >> >> I am not a supporter of ethanol gas but it here and I ain't got no >> choice. >> SO I MAKE IT WORK >> >> -------- >> Rotax Dealer, Ontario Canada >> http://www.cfisher.com/ >> Awesome *New Forum * >> http://rotaxaircraft.com/forum/ >> Realtime Kitfox movies to separate the internet chatter from the truth >> http://www.youtube.com/profile_videos?user=kitfoxflyer >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=316801#316801 >> >> >> >> >> >> >> >> >> >> >> > > > -- > Barry > "Chop'd Liver" > ________________________________ Message 15 ____________________________________ Time: 05:19:53 PM PST US Subject: RotaxEngines-List: Follow me on Spot tomorrow to Yuma, AZ From: "Roger Lee" I'm flying to Yuma, AZ again tomorrow at 0830 Mountain Time or AZ. time today. You can track me as I go. I will leave at 0830 and arrive in Yuma at approximately 1030. I come home Friday late afternoon at 1530 hrs. and will be back in Tucson at 1730 hrs. mountain time. You can follow me by clicking on the link above where it has my Spot Tracker link. http://share.findmes...4WO25eB0VkBu5Iv -------- 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=317033#317033 ________________________________ Message 16 ____________________________________ Time: 07:03:24 PM PST US From: "Noel Loveys" Subject: RE: RotaxEngines-List: Re: 100ll 100% of the time I agree with most of what you said except the government getting rid of ethanol. Sooner or later they will have no option but get rid of it. Noel -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Roger Lee Sent: October 25, 2010 1:58 AM Subject: RotaxEngines-List: Re: 100ll 100% of the time I'm with you guys. I don't like 100LL and I don't care for ethanol either, but since I have to pick one over the other, ethanol wins hands down compared to all the leading. The lead really is the worst choice. I don't see the government getting rid of ethanol so you and I might as well learn to deal with it, but we can do it more on ours terms by making our fuel systems ethanol safe. -------- 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=316926#316926 ________________________________ Message 17 ____________________________________ Time: 08:37:08 PM PST US From: "Noel Loveys" Subject: RE: RotaxEngines-List: Re: Washing Ethanol out of Gas They use a process called a flash test. Basically they heat up a metal plate to a specific temperature and then drop a single drop of fuel on it. The temperature of the plate which causes the fuel to flash is what they are looking for. The higher the octane rating the higher the temperature required to flash. In the past volatility and high octane levels were confused because older high octane gasoline was a lot more volatile than lower octane gasoline. BTW someone once told me that I could increase the octane of any fuel by adding a bit of kerosene or Diesel fuel to it... This obviously is not true. Diesel fuels are very low octane so they do not require a spark to get them to flash inside the engine. Conversely Ethanol while very low in btu per unit volume a is actually a high octane fuel (RON116) This is why when you wash the ethanol out of your gas you will see a slight decrease in RON. Using my grade two arithmatic I estimate the drop to be under three points drop for removing 10% booze. Noel -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com] On Behalf Of Roger Lee Sent: October 25, 2010 8:34 PM Subject: RotaxEngines-List: Re: Washing Ethanol out of Gas Hi Barry, The fuel was tested at a lab before washing and the same fuel tested after washing. I don't know the exact method the lab used to define the octane rating. The first sample of the untreated fuel was right on and the washed fuel test results looked right in line with what you would expect. -------- 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=317024#317024 ------------------------------------------------------------------------------------- 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.