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You think by using modern ignition systems you can use MOGAS on an IO-390 without engine modifications and without losing lots of power or lifetime? |
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Have a look at this
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Here is an STC'd $12,000 water injection system for IO 520 Continentals If you watch the first 2 minutes you will see the MP and CHT values the system starts flowing at. Mostly at take off power settings with MOGAS A slightly different tool to address pre ignition / detonation that lets you maintain high MP and normal advance for rated HP output. |
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2 - road fuels in the US are rated in AKI not RON. AKI is (RON+MON)/2. You'll see that formula shown on pumps |
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In any case, under 9 to 1 Lycomings can safely use 91 AKI with proper timing adjustments and care with AFRs. Under 7.5 CRs ones can run on 87 AKI with the same care. The Swift UL avgas is higher octane and certainly suitable as well. The "universal" UL avgas, when it's introduced, is likely to be similar in octane rating to the current 100LL so as not to have to derate the current turbocharged engines too far, if at all. |
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Has anyone tried to use in-tank pumps with EFI? You'd nearly eliminate the vapor lock issues (pretty hard to vapor lock at 2-3 bar), extend pump life, and have automatic redundancy. |
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We strongly recommend that people use what's been proven over a half million flight hours with regards to the EFI fuel system if you don't want surprises or to be on a test program to validate a new design. |
[quote=BMC_Dave;1284442]Huh, that's interesting thanks for the link!
Here is a much deeper look at the history and some of the early research and aviation user data. https://youtu.be/1PA70pN6zPM?t=4m8s A bit long but a lot of good information. |
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It would make plumbing slightly more difficult and it would be a lot harder to change a pump in the event of a failure but no more difficult than a bad fuel sending unit. And yeah I get the "don't rock the boat" comment. I was just curious if anyone had tried dual in-tank pumps in an aircraft before. |
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In aviation, once we have demonstrated the reliability of a layout or system, we repeat that without deviation to get the same results over and over. If you want to put pumps in the tanks, you could. I've just outlined the main reason it's not done. We have a proven, very reliable layout now with few drawbacks. I'm not sure why it would be a good idea to change that. What would be the advantage over the existing layout? |
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And I understand the current setup is quite reliable. I am not at all questioning that. However in-tank pumps live a happier/cooler/quieter life and you don't have to worry about vapor pressure at all and the packaging is a bit simpler since most of the bulk lives in the tank. It's more of a question of "has it been done" and "why not if not?". Here is a random image I found that describes the setup. Just imagine each side of the saddle is a wing: ![]() |
Motive Flow
Same as motive flow? Motive flow is used in fuel tanks of most biz jets I'm familiar with.
Here's a basic description I found. https://aviation.stackexchange.com/q...raulic-systems |
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This being experimental aviation, nothing is stopping you from implementing your ideas on your aircraft if you see some advantages there. I just don't see any advantages with this layout. |
SHELL?S FUEL UNDER STUDY
Most recent AOPA article on 100LL replacement. EAA had a similar article.
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AOPA video https://www.aopa.org/news-and-media/...n=180830epilot could be related to what RV10inOz brought up in his post. |
Will be interesting to see how this all shakes out. Shell has the size/ funding and existing network to make this happen more quickly IMO than the other players but hopefully Swift and GAMI will also be in here as alternative competition.
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Interesting this debate is still going on. Fifteen years ago when I was making the decision on the engine and fuel system for my 7A everyone was worried then that 100LL was on it's way out. If there is a large enough market, someone will continue to produce it, or a reasonable substitute.
Roberta |
Shell developed a really cool new paint stripper. SWIFT won't start in Winter or if you brew it synthetically the components cost north of $12/gal before you get started. And it didn't work (not when my data source was current).
Neither is fungible with the existing avgas. At some point you need to have a changeover period and a long and lengthy one at that. One fuel does tick all the boxes and does better in some areas than current 100LL., and it was never part of the fatal flawed PAFI project. Make of that what you will. And just because one company is huge and has large cash sources does not mean that they can or will solve the problem. They haven't. |
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It's one thing to come up with a recipe that ticks all the boxes, quite another to get this in world wide or at least country wide distribution. There is at least one other US player developing UL avgas outside of PAFI, who few people know about. I was just talking to someone in that company last week and they have a very good formulation it sounds like. |
Ahhh memories. There once was a time when this website didn?t exist. RV builders communicated via an email list where we either received one email containing all of the emails for the day or hundreds of emails spaced apart by seconds. It was great. Back when that list was an infant was the first time I heard someone say with certainty that Low Lead was going away shortly and we were all doomed.
I am still waiting....but I did finally stop holding my breath. So, until Hades freezes over and the seas of Low Lead dry up....I?ll keep destroying the environment with buckets of lead, bragging about my carbon footprint and whacking every baby seal I see on the head with a hammer. |
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![]() Which is the only supplier of TEL - tetra ethyl lead, the lead bit of 100LL - in the free world. https://www.petro-online.com/news/me...ol-legal/43931 Every time I go to Liverpool I look across the river to see that the plant is still there :) It was still there a year ago. |
Lead free
Lead free racing fuel has been around for a while at Sunoco. Granted it?s high cost, but if I recall, it was something like 110 octane. If the stuff would work in AC, then I wonder what the cost would be if the supply chain was a larger?
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130 Octane
Does anybody have the accurate records for the make up of 130 Octane gasoline that was used in the 1940's when Mustangs, Spits and other merlin powered AC used it?
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100LL Update
Latest update (Sep 7, 2018) on the Piston Aviation Fuels Initiative (PAFI) from the FAA website.
FWIW: "...PAFI flight testing and some engine testing was halted, resulting in a delay in testing completion ? from December 2018 to mid-2020." https://www.faa.gov/about/initiatives/avgas/ I'll continue to check the website daily for further updates :) . |
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http://www.wwiiaircraftperformance.o...grade-spec.pdf And lots of history on the introduction of 150 to replace/supplenet 130 octane fuel in WWII Lots of links in the footnotes - http://www.wwiiaircraftperformance.o...rade-fuel.html |
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Just a slip of the keyboard.......... when G100UL gets out there (soon) it will perform like the old purple gas and I have seen the test reports from Dixie Labs.
Lots of good things..........but geez it takes time........ |
Sorry, I apologize ahead of time for this post, but I only get on this soapbox once a year.
For those interested, here's an update (June 20, 2019) on the PAFI program from the FAAs website. https://www.faa.gov/about/initiatives/avgas/ I attended the PAFI forum at OSH this year hosted by reps from EAA, AOPA, and FAA. Unfortunately, no announcement of any breakthrough was discussed. According to the panel members, tetraethyllead (TEL) was the "magic bullet" in the 1920s and it remains so today. They stated there is no simple fix and were actively inviting new participants with ideas to join the program. A question was asked by someone in the audience as to why eliminating AVGAS was such a big deal since, "in the big picture", it produces such a small amount of lead emissions. The panel agreed that is is a very small amount of lead however, "it's a done deal". Suits filed from environmental groups beginning in 2006 are still on the books, and while no action has been taken since around 2012, the fact remains. The panel mentioned several times "we are committed to removing lead from AVGAS". They are probably required to make that statement not knowing who is in the audience. All that said, AVGAS probably not going away anytime soon, I understand that. However, I do find it interesting that engine manufacturers continue to build, and more importantly we continue to BUY, engines that require a fuel the FAA, EPA, and other agencies continue to state they are committed to eliminate. I wonder if a better path for the last several years may have been spending time and money (I think $35 million was the amount congress gave the PAFI program), in researching and developing engine solutions rather than a replacement fuel. During that time, airplanes would have continued to burn 100LL, and as TBO's and service life of these engines were reached it may have been possible to replace with an updated engine that doesn't require AVGAS. My vote would be for a JET A because of world-wide availability, ease of refinement and distribution, and only one pump required at the airport. Don't get me wrong here. I don't want AVGAS to go away anytime soon, I sure enjoy flying my buddies RV10 when I get the chance. However, I want a long term solution so future generations can have the opportunity to enjoy flying small airplanes like we have. I'm just not convinced a replacement fuel is the answer. |
Several big companies continue to work on a 100LL replacement both within and outside PAFI. It takes a long time to gather test data which will satisfy the FAA. Some have not submitted anything to the FAA yet while the formulations undergo independent testing.
It will have to have similar density and other characteristics to be approved. Not so easy as it seems. No way new engines will replace what's in the fleet now, any time soon. Not practical on so many levels, both technical and economic. |
For those interested, here's the latest update from the FAA on the 100LL replacement program (PAFI).
https://www.faa.gov/news/fact_sheets...m?newsId=14754 |
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I don't believe we have to worry about LL fuel not being avail for quite a long time yet! The issue might be cost in the future, availability is the least of our worries. So fly fly fly:D
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Fuel
Maybe some of our colonial brothers from accross
the pond would chime in here. A few years ago in Great Britain they allowed you to burn ?auto fuel ? in several types of aircraft. One of the restrictions was not flying above ?4000 ft. Run down to your neighbor hood gas station fuel up and take off in the summer months then climb up to cool off and you would be surprised how many people encounter ruff running engine problems that are probably the onset of vapor lock problems. |
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