EarthboundMisfit Posted June 21 Report Posted June 21 Very informative stuff from Martin Pauly. More energy content than 100LL - yes please! 2 Quote
NickG Posted June 22 Report Posted June 22 Yes, I watch all of Martin's videos... I can't wait for this to be available in my area. Quote
Fly Boomer Posted June 22 Report Posted June 22 44 minutes ago, jetdriven said: Who is martin pauley Makes a lot of aviation videos -- mostly Beech related. Quote
tony Posted June 22 Report Posted June 22 finally, an OEM with common sense https://www.aopa.org/news-and-media/all-news/2024/june/19/cirrus-advises-g100ul-use-may-void-warranties?utm_source=epilot&utm_medium=email Quote
hammdo Posted June 22 Report Posted June 22 17 hours ago, EarthboundMisfit said: More energy content than 100LL - yes please! And heavier too… 6.3lbs Quote
bonal Posted June 22 Report Posted June 22 This subject is getting so old. Please educate me there are at least three major producers of 100 plus unleaded fuel shell, Sunoco, VP plus others that are less well known. Is there some magical chemistry needed I understand it’s a certification thing like so many other issues we have to put up with I just don’t know why it has to be such a Problem getting it done. Personally I don’t think our very small percentage of lead is causing anyone any health problems just like most of the other made up issues that ultimately are used to take away our freedom. But hey, that’s just my thoughts on the issue. there isn’t anything special about my old o360 5 Quote
Pinecone Posted June 22 Report Posted June 22 First, Pump Octane or AKI is not the same as AVGAS octane. Pump octane is nominally around 5 points higher than MON (Motor Octane Number) that is similar to AVGAS Octane Second, those higher octane motor (car) fuels typically use oxygenates to get there. Not so good for aircraft engines. 2 Quote
Ibra Posted June 22 Report Posted June 22 (edited) 3 hours ago, bonal said: there are at least three major producers of 100 plus unleaded fuel shell, Sunoco, VP plus others that are less well known Out of all these, the only candidate who have promising on “PAFI route” are VPRacing, they already have something similar to their C10 fuel that apparently passed initial PAFI testing in 2023 and now they have 6 months or 1 year to come up with “ASTM Avgas”. Yes in the past, VPRacing did lot of “high octane and/or high etanol” Mogas with ratings that would exceed 100LL (E102, M103, VP-C16, X98..), however, many of these will eat lot of rubber in an aircraft and they do lot of oxygen bubbles: they do not work in aircraft airframes (unless one put lot of pressure on fuel tank and fly full power at sea level). We will see if they can make an Avgas? If you look at their fuels, it’s hard to get octane (MON) > 100 without lead (TEL) or oxygen (O2) https://vpracingfuels.com/master-fuel-tables/ For “STC route”, we have GAMI G100UL (and Swift UL94), these seems to do the job for octane, however, we will hear more and more about new aromatics: it seems engine and airframe manufacturers are not too keen (Lycoming are not touching G100UL with barge pole, I am not sure if it’s fear of change, fear of liability or something well founded) Does anyone knows what G100UL is made from? other than “ink” Edited June 22 by Ibra 2 1 Quote
bonal Posted June 22 Report Posted June 22 Thanks for the information. Too bad we’re so overly protective these days that everything is considered life threatening. I’m more concerned with valve recession than I am of lead poisoning. Hope they come up with a reasonable solution before they ban all gas engines. I’d like to keep flying for at least a few more years. 3 Quote
Fly Boomer Posted June 22 Report Posted June 22 1 hour ago, Ibra said: Lycoming are not touching G100UL with barge pole, I am not sure if it’s fear of change, fear of liability or something well founded I have read that Lycoming has had their panties in a twist when it comes to GAMI for a long time. I gather that they got indignant when the upstart (GAMI) was either discovering or revealing characteristics about their engines that they were unable, unwilling, or uninterested in discussing. 1 Quote
McMooney Posted June 23 Report Posted June 23 (edited) I"m happy g100ul is available but terrified they will remain the only option if the other fuels fail to gain certification, with an almost mandated, unassailable monopoly, i'd expect private equity firms to buy gami and completely shaft us. Edited June 23 by McMooney 2 Quote
EarthboundMisfit Posted June 23 Author Report Posted June 23 8 hours ago, hammdo said: And heavier too… 6.3lbs A 0.3lb increase over 100LL. Not a deal breaker for my operations. 1 Quote
jetdriven Posted June 23 Report Posted June 23 2 hours ago, EarthboundMisfit said: A 0.3lb increase over 100LL. Not a deal breaker for my operations. It contains more energy per gallon, so the range is either the same or slightly more for the same fuel load in lbs. 2 Quote
mhrivnak Posted June 23 Report Posted June 23 3 hours ago, McMooney said: I"m happy g100ul is available but terrified they will remain the only option if the other fuels fail to gain certification, with an almost mandated, unassailable monopoly, i'd expect private equity firms to buy gami and completely shaft us. There's only one lead supplier for 100LL, so we're already at the mercy of a monopoly. 2 Quote
mhrivnak Posted June 23 Report Posted June 23 6 hours ago, Ibra said: Does anyone knows what G100UL is made from? other than “ink” Apparently all of the details are in their patents, which are public. Maybe this has the info you want? https://patents.google.com/patent/US8628594B1/en 1 Quote
Ibra Posted June 24 Report Posted June 24 (edited) GAMI has responded to Cirrus https://www.avweb.com/aviation-news/gami-responds-to-cirrus-g100ul-service-advisory/ It seems like an overreaction (extrapolation from one single aircraft incident? one data point statistics?), however, the concern about new aromatics in unleaded fuels and fuel tank sealant is something every Mooney pilot would take very seriously Does anyone know if GAMI tested their G100UL in Mooney airframes? GAMI tested G100UL on SR22 extensively, as it's the main candidate, I doubt they missed this? in any case, it does not sound like a problem with the engine, rather concerns about tank material compatibility Edited June 24 by Ibra Quote
EricJ Posted June 24 Report Posted June 24 At the Buckeye Air Fair this year I heard George Braly say that their aromatic content is higher than current fuels and will be more reactive with some materials, and he even said specifically to not let it get on your paint. I think Cirrus may have just taken that one incident as the canary in the coal mine for an expected problem, which I think isn't out of order. Until it's known what it'll do, given that it is expected to be a potential issue, it's prudent for them to be careful. Also, fwiw, this may be an issue for any of the replacement candidates until more is known. 3 Quote
Ibra Posted June 24 Report Posted June 24 (edited) 37 minutes ago, EricJ said: Until it's known what it'll do, given that it is expected to be a potential issue, it's prudent for them to be careful. Yes for airframe materials, it's not clear what are adverse effects and testing may require long term feedback than "next 6 months"? GAMI "secret ink" to get higher octane (alkyl benzene) seems to available around and it's used in printers (it does not sound to be harmful even when mixed with food packaging in stores) https://www.researchgate.net/publication/279625885_Analysis_of_alkyl_benzenes_in_printing_ink_on_food_packaging_materials_and_its_migration_by_gas_chromatography-mass_spectrometry Alkyl Benzene does not sound like making TEL or Freon (one guy made both of them at General Motors), it's already something used in everyday life applications: ink, soap, shampoo, toothpaste, laundry...the only caveat it seems that most of these applications are for detergents !! For other ingredients (aromatics and stabilisers), we will have to see Edited June 24 by Ibra Quote
M20F Posted June 24 Report Posted June 24 On 6/23/2024 at 12:25 AM, mhrivnak said: There's only one lead supplier for 100LL, so we're already at the mercy of a monopoly. India just started a 100LL refinery and intend to export. The whole deal with aviation fuel is the temp extremes coupled with it not degrading. You can toss 100LL in a plane and 5yrs later start it at -40F. Try doing that with car gas. I would rather the effort be spent on engine technology than a new gas myself. 1 Quote
1980Mooney Posted June 25 Report Posted June 25 1 hour ago, M20F said: I would rather the effort be spent on engine technology than a new gas myself. You mean like DeltaHawk? 1 Quote
M20F Posted June 25 Report Posted June 25 19 minutes ago, 1980Mooney said: You mean like DeltaHawk? I mean like anything, the main issue with airplane engines is the need for octane to offset detonation. A lower octane engine that could run on auto fuel would be the win. Quote
Pinecone Posted June 25 Report Posted June 25 13 hours ago, Ibra said: Yes for airframe materials, it's not clear what are adverse effects and testing may require long term feedback than "next 6 months"? GAMI has a Cirrus that has had G100UL in it for 14 YEARS without issues. Is that long enough? 1 Quote
Ibra Posted June 25 Report Posted June 25 (edited) 16 minutes ago, Pinecone said: GAMI has a Cirrus that has had G100UL in it for 14 YEARS without issues. Is that long enough? Indeed, I think that is enough for SR22, one can argue that G100UL was mainly for SR22 engine and airframe (being the only piston that is sold in enough numbers) I was thinking about other airframes like Mooney? we have wet wings and quality of sealant in tank is a big concern for Mooney owners. On Avgas 100LL, some lucky Mooney owners still fly with factory sealant, the unlucky ones tend to redo it every 15 years Edited June 25 by Ibra Quote
N201MKTurbo Posted June 25 Report Posted June 25 12 hours ago, M20F said: I mean like anything, the main issue with airplane engines is the need for octane to offset detonation. A lower octane engine that could run on auto fuel would be the win. Any of our engines can be modified to run on auto fuel. But there would be a performance or reliability issue. Getting most of our engines to run on car gas would only require a reduction in spark advance. Some may also require a reduction in compression. This will decrease its max power output. The only way to recover the lost power is more displacement or higher RPM. Our propellers limit our RPM, so to get higher engine RPM and keep the propeller from overspeeding, we would need a gearbox. Geared engines are generally heavier and less reliable. Our engines have been optimized for reliability and power to weight ratio. changing them will require compromising on one of the three. There is no modern magic that will change any of this. It will be interesting to see how the DeltaHawk does in real day to day service. We will probably not know for sure for a decade or two. 1 Quote
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