NC Bill Posted January 22, 2011 Report Share Posted January 22, 2011 I assume by MOGAS it means I can bring fuel from the gas station in 5 gal cans to the plane. If so what octane 91? or 93/4? Any special precautions or do/don't filling the wing tanks? TIA, Bill Link to comment Share on other sites More sharing options...
CT4ME Posted January 22, 2011 Report Share Posted January 22, 2011 "Premium" MoGas, 91 octane or better (from a busy station). Up to 10% ethanol (the less the better). 5-6 gallon containers, or some folks have fancy mobile rigs that hold more and have pumps. Random thoughts on fueling'... * Some airports may not allow it or want to control it. Mine requires you watch a movie, take a test, and pay for a permit - before you can self-fuel * Have a couple of appropriately-rated fire extinguishers nearby * Use something like a "Mr. Funnel" to strain fuel and remove water * Make sure your step stool or ladder is rated for your weight, PLUS the weight of fuel (another 36 lbs) * Careful to not scratch wing * Have rag nearby to cleanup sloshes * I prefer to have a vented can, so fuel empties quicker. But too much can overflow your funnel. * Always ground yourself by touching plane, and make sure nobody is getting in/out or messing around while you fuel * Don't overfuel - leave some room. If plane is at an angle, fuel can flow from side to side and may cause an overflow spill. ... I'm sure someone will think of more... Tim Link to comment Share on other sites More sharing options...
coppercity Posted January 23, 2011 Report Share Posted January 23, 2011 "Premium" MoGas, 91 octane or better (from a busy station). Up to 10% ethanol (the less the better). 5-6 gallon containers, or some folks have fancy mobile rigs that hold more and have pumps. Random thoughts on fueling'... * Some airports may not allow it or want to control it. Mine requires you watch a movie, take a test, and pay for a permit - before you can self-fuel * Have a couple of appropriately-rated fire extinguishers nearby * Use something like a "Mr. Funnel" to strain fuel and remove water * Make sure your step stool or ladder is rated for your weight, PLUS the weight of fuel (another 36 lbs) * Careful to not scratch wing * Have rag nearby to cleanup sloshes * I prefer to have a vented can, so fuel empties quicker. But too much can overflow your funnel. * Always ground yourself by touching plane, and make sure nobody is getting in/out or messing around while you fuel * Don't overfuel - leave some room. If plane is at an angle, fuel can flow from side to side and may cause an overflow spill. ... I'm sure someone will think of more... Tim couple more... * if you think your plane may sit for over a month then minimize the auto gas and fill up with some 100ll. The additives in the mogas can start gunking things up over time and collect moisture. 100ll is safe for long storage. * I like the metal safety cans from Lowes, they have good leak proof spring loaded caps, a built in funnel for easy pour into a Mr. Funnel, and they can pour a lot faster then the plastic type, also you can ground them easily to the plane with a wire and alligator clips. *keep your fueling area well ventalated, those fumes are nasty and explosive. *Avoid doing static inducing cleaning and wiping of your plane right before you fuel. Fuel first then clean. Link to comment Share on other sites More sharing options...
sandpiper Posted January 23, 2011 Report Share Posted January 23, 2011 I like this: www.tuffjug.com. I got mine from www.cyclegear.com. These are pricey but they work as advertised. In addition I have a 16 gallon (they also come in 30 gallon) barrel with compressed air. See www.bykas.com/fun-fueler. Again, pricey. I got mine at a big discount. Seems that, in farm/ranch country, you can't sell these to farmers/ranchers who will make their own at much less cost. Link to comment Share on other sites More sharing options...
wlfpckrs Posted January 23, 2011 Report Share Posted January 23, 2011 Raleigh East Airport (W17), Knightdale, NC has mogas without ethanol, but it's 87 octane. I've been mixing two 5-gal containers of this mogas with one 5-gal container of 100LL lately. Link to comment Share on other sites More sharing options...
Roger Lee Posted January 23, 2011 Report Share Posted January 23, 2011 You should never mix less than a 50/50 mix. Anything less will result in a less than 91 Oct. mix. More 100LL is ok, but not less. This is taught in all Rotax classes. Mixing less than than a 50/50 mix could easily damage the engine with detonation. May not happen the first time, but you will eventually suffer some problems and they will be sooner than later. Link to comment Share on other sites More sharing options...
chanik Posted January 26, 2011 Report Share Posted January 26, 2011 You should never mix less than a 50/50 mix. Anything less will result in a less than 91 Oct. mix. More 100LL is ok, but not less. This is taught in all Rotax classes. Mixing less than than a 50/50 mix could easily damage the engine with detonation. May not happen the first time, but you will eventually suffer some problems and they will be sooner than later. I didn't get this in my recent class. I don't see it anywhere in the ROTAX documents either. I think his math works here with 2/3rd 87 and 1/3rd 100 averaging to 91.3 Octane. Octane improvement due to TEL or Ethanol in gasoline is linear for low volumes of either. The more interresting issue for me is the debatable claim that MOGAS will lose a few points of it's octane after a month or two. That's a pretty dubious assertion. Perhaps in extreme heat, the alcohol could preferentially evaporate after a few months since it has lower vapor pressure. If you lost 1/2 the Ethanol Octane would drop about 1.5 points. Also, if you saturated the fuel with water so that the ethanol actually separated out, I'd consider that a big deal and drain the tanks to do at least 50/50 of 100LL. 20Gal of E10 can absorb just over 1Gal of water before it separates so that's alot of water before you see it in a strainer. However, it is worth noting that moisture in fuel actually INCREASES octane. 5% water emulsified in gasoline would boost octane 2-3points. Granted the energy will also be ~5% less since water doesn't exactly burn so well but the boost is well researched and has historically been used in practice. Many WW2 plane engines used water boost or 50/50 water/methanol boost for war emergency power. Link to comment Share on other sites More sharing options...
chanik Posted May 5, 2012 Report Share Posted May 5, 2012 I did a round trip from San Jose to Chandler AZ last week and tried this out, mostly because I suspect I may only find 87Octane in some remote areas of Alaska I plan on visiting. So I want to be sure I could use, say, 8 Gal of remaining 100LL with 16Gal of E10 87 Oct. I burned 24Gal of 91Oct MOGAS on the way over (580nm) Then added the 87 and 100LL. Jiggle plane wings well. OAT was about the same coming and going. I can see no difference in EGT or CHT at all which are the first signs you are getting closer to detonation. Link to comment Share on other sites More sharing options...
Roger Lee Posted May 5, 2012 Report Share Posted May 5, 2012 Hi Kurt, Minimum blend from Rotax is 50/50. No more than 50% 87 oct. Too much 87 may be okay one trip, but if the circumstances change a little you may end up with detonation and not know it until it's too late. That's what happens to most, they never know until the engine starts to sputter then there is a hole in the piston and burnt rings and it's too late. You can easily have detonation and no warning with the gauges Link to comment Share on other sites More sharing options...
chanik Posted May 6, 2012 Report Share Posted May 6, 2012 If I do the math, 30% 100Octane averages with 70% 87Oct to 91Oct. I can easily see where Rotax would be very conservative and say 50/50 though. I do know that EGT climbs up predictably vs lower octane fuels with all other stoichiometric conditions the same, so why do you think the gauges won't show this? Link to comment Share on other sites More sharing options...
Roger Lee Posted May 7, 2012 Report Share Posted May 7, 2012 Hi Kurt, It's the better safe than sorry fuel ratio. It only takes a few seconds to spend $4K-$6K+ with a detonation. Link to comment Share on other sites More sharing options...
chanik Posted May 7, 2012 Report Share Posted May 7, 2012 Sure, but I maintain that I would see a small decrease in Octane manifest in EGT rise well before I start blasting pistons. I was right at 91Octane with the mix anyway. An experiment I'm not willing to try would be finding out what the real tolerance is for lower octane. I'm sure there is some buffer in the design below 91, but I don't think it is much. Automotive engines WITHOUT knock sensors are generally designed below 10:1 to safely allow for low octane fuel and they run mainly in the 3-4K RPM range (you can get by with lower octane using higher RPM). So I suspect the 912 at 10.5:1 and at 5K RPM would run fine on even 87 but the EGT would climb up substantially and you would indeed be close to the edge of detonation. I'd love for someone else to try it... Link to comment Share on other sites More sharing options...
Roger Lee Posted May 7, 2012 Report Share Posted May 7, 2012 Hi Kurt, Here is something you and others may not know. The 10.5:1 compression ratio in the book has always been a misprint . It is really 11:1 That's straight from Rotax. That might push you ratio a tad more. Link to comment Share on other sites More sharing options...
airhound Posted June 5, 2012 Report Share Posted June 5, 2012 Any comments regarding use of Seafoam either added to gas or oil? Link to comment Share on other sites More sharing options...
Roger Lee Posted June 6, 2012 Report Share Posted June 6, 2012 I would leave it out of the oil. The oil absolutely won't need it because it should be a synthetic. I see no reason to put it in the fuel. If you are flying once every 6 weeks and adding fresh fuel your good to go. If you are leaving fuel sit in the plane for 3+ months drain it and dump it in your car. If you know the plane is going to sit for long periods then add some 100LL for stabilization. Seafoam will not hurt the engine in the fuel, but I don't think it helps as much as some would like to believe and most fly within reasonable time limits any way. Link to comment Share on other sites More sharing options...
Jim Meade Posted June 6, 2012 Report Share Posted June 6, 2012 Here is what the Sea Foam company says it's product does. Roger has it pretty much pegged. Old petroleum residue (gum and varnish) buildup. All fuels and engine oils leave behind residue deposits that accumulate over time. In the crank case, this residue builds up around lifters and rings, preventing them from functioning properly. In the fuel system, residue builds up in the injectors or carburetor jets, on the tops of pistons and on the backs of intake valves. Carbon in the exhaust adheres to this residue and forms carbon deposits. THERE IS NO DIFFERENCE BETWEEN THE RESIDUE IN YOUR CRANK CASE AND THE RESIDUE IN YOUR FUEL SYSTEM. IT IS ALL PETROLEUM VARNISH. Sea Foam helps slowly and safely re-liquefies this varnish so contaminants and carbon deposits can be safely cleaned out of the systems as the engine is operated. Lack of lubrication. This can occur in the fuel system as the result of dry fuel additives such as ethanol that actually remove lubrication from the engine components. In the crank case, varnish buildup around the lifters and rings can prevent the oil from properly circulating and lubricating. Moisture. Fuel can absorb moisture from the atmosphere - even more so with the addition of ethanol. Crank case oil can also become easily contaminated with moisture. Sea Foam fully encapsulates the water molecules in the fuel to prevent phase separation - rendering the absorbed moisture harmless. Link to comment Share on other sites More sharing options...
airhound Posted June 7, 2012 Report Share Posted June 7, 2012 Thank You Jim and Roger! Link to comment Share on other sites More sharing options...
Johnny Posted December 7, 2012 Report Share Posted December 7, 2012 Hey guys, Great discussion ... I always learn something here! I know our birds are supposed to do ok with ethanol but if u can avoid it, it may not be such a bad thing, huh? Just ran across this little blurb for testing for ethanol. Haven't tried it yet but I'm gonna. Many of you are probably hip to this already, but for who are not, I hope it helps! The thread also includes a link for stations that are ethanol free. http://www.generalaviationnews.com/2012/12/05/ethanol-testing-made-easy/ -- Johnny Link to comment Share on other sites More sharing options...
Doug G. Posted December 8, 2012 Report Share Posted December 8, 2012 As I understand it the water absorbed by ethanol in gasoline is not likely to reach a point where it would ever separate. Gasoline does "get old" however. I don't know exactly what that involves, but I know what it means in my mower over the winter. I use tough jugs with the adapter on the nozzle which raises them so all the gas will dump, otherwise the tip of the nozzle is too deep in the tank and it stops early. They empty quickly, so you don't have to hold them very long. These are used to fuel racing bikes and sprint cars, so I wonder about the static issue. (It may fall in the category of the disproven theory of cell phones causing static discharge. I also use a Mr. Filter, but I have not, and don't expect to find any water given ethanol's ability to absorb water. The filter will not separate the absorbed water from the gasoline. I filter it at the pump, and you need a waste container because the filter does not completely drain. Link to comment Share on other sites More sharing options...
Dan Kent Posted December 10, 2012 Report Share Posted December 10, 2012 Hey guys, Great discussion ... I always learn something here! I know our birds are supposed to do ok with ethanol but if u can avoid it, it may not be such a bad thing, huh? Just ran across this little blurb for testing for ethanol. Haven't tried it yet but I'm gonna. Many of you are probably hip to this already, but for who are not, I hope it helps! The thread also includes a link for stations that are ethanol free. http://www.generalav...ting-made-easy/ -- Johnny Johnny, I just bought one of these. It not only tests for the presence of ethanol but give an idea of the amount of ethanol. It has a graduated scale from 0% to 30%, but you can really only get an idea within about 2% as the scale is so tight that it is hard to interpolate. I live in the Houston area and knew I was going to get ethanol in the gas, so I got this to try and find a station that had less than the 10%. I'm fortunate as I tested 4 stations this weekend (my fuel caddy needed filling). There's an Exxon station on the way to the airport that is very busy and has good prices that I have been using for months. Come to find out their ethanol content is approx 5%, so I'm sticking with them. I sampled the gas caddy which was about 5% and a new 5 gallon jerrycan which also was about 5%. I'll keep checking stations periodically to see if I can find even lower amounts. http://www.shopeaa.com/alcoholtestkit.aspx Link to comment Share on other sites More sharing options...
Doug G. Posted December 11, 2012 Report Share Posted December 11, 2012 Unfortunately 10% is mandated in MN. I could go to the ND side and find ethanol free, but the drive would increase the cost. Especially when I usually only buy 10 gal. At a time. Link to comment Share on other sites More sharing options...
Roger Lee Posted December 11, 2012 Report Share Posted December 11, 2012 Most gas stations that say up to 10% (AZ too) are not usually that high. They actually tend to be around 6%-8%. Even if it was 15% I personally still wouldn't worry about it especially if the alternative was 100LL.The Rotax and CT can handle it.The Rotax can handle ethanol over 20% (as proven by its use in Brazil), the better fuel line like the Gates Barricarde fuel hose can handle 100% and the Kreem Wisse fuel tank coating that FD uses can handle a lot more than 10% ethanol too. Other aircraft may need some investigation on their fuel tanks. Link to comment Share on other sites More sharing options...
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