Drop-in 100LL Replacement "Impossible"?

Show me where the gummint is holding GAMI back....they just approved an AML wide STC for the use of G100UL. Supply and demand is at work here.....;)
 
1. GAMI decided a long time ago to avoid ATSM. Based on round about comments on a few forums, none of which I recall directly quoting, it was due to previous issues, some technical, mostly around IP concerns and NDA violations. I do recall seeing quotes from George, that ATSM is unacceptable or something along those lines.
2. PAFI/EAGLE started with a fundamentally different set of requirements than George B at GAMI did. PAFI started with the assumption that you needed to make a drop in replacement that matched the existing ATSM spec of 100LL without TEL; and work with ATSM to update the specification as needed. George defined the requirements as you needed a fuel which works in the existing fleet without modification. The existing ATSM spec was created after 100LL was in use, and basically documents almost every testable metric at the time for a combustible fuel. EAGLE has slightly changed the requirements compared to PAFI, but I do not recall seeing details of the changes. Supposedly EAGLE moved slightly in the direction of GAMI's requirement definition but not completely.
3. The VP of the racing fuel company, is very likely correct when taken within the constraints of EAGLE.
4. A number of FBOs/Distributors or others, I am never sure who, have been making noise that to be a commercial product and protect against liability, the fuel must meet an ATSM spec.
5. At this point, there seems to be a crap ton of politics, and also fear of accruing any liability which are the primary blockers for G100UL.
6. In general, paper pushers can never get in trouble for saying no. But they can get in trouble for saying yes.

Tim
 
Checkout_my_Six said:
Show me where the gummint is holding GAMI back....they just approved an AML wide STC for the use of G100UL. Supply and demand is at work here.....;)
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Well, FAA launched EAGLE to develop a lead free formula after GAMI was already proven. Sen Baxter a year or two ago put in reauthorization bill to require lead in av gas. FAA could simply buy the GAMI formula and make it the approved formula. Someone else said it above - it’s not a technical issue, it’s a paper work / bureaucratic issue.

tspear said:
In general, paper pushers can never get in trouble for saying no. But they can get in trouble for saying yes.
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StraightnLevel said:
...3) Local governments that operate and attempt to regulate airports. Some want to ban leaded fuel, some don't want the boat rocked, and none want to spend any of their own money....
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An interaction I had with a county supervisor gave me the impression that some local government officials don't want to lose a pretext for closing airports. :mad:
 
tspear said:
The existing ATSM spec was created after 100LL was in use, and basically documents almost every testable metric at the time for a combustible fuel.
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Exactly. The current spec was written to describe 100LL, not to specify the parameters of any fuel that would work. Consequently, 100LL is the only possible fuel that will match a 100LL spec.

GAMI’s approach to the problem was much more reasonable.

I suspect EAGLE is just trying to run out the clock. I believe the G100UL patents expire around 2030.
 
WDD said:
It’s not the greed, etc. that’s the problem. It would work out just fine if the gov would allow the best solution to enter the market and let the chips fall where they may. The guy who came up with GAMI was probably “greedy” when wanting to make a profit with his formula. He should be allowed to do so.
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I completely agree with that. All the non-GAMI rest that had or have invested money in either an alternative or existing (100LL) have a lot to lose, so they are understandably protective. However, the technical truth becomes hard to determine with all of these instincts. Add in politics and litigious conservatism and here we are 50 fkn years later.
 
I encourage everyone to view the important part in the video that Martin posted -- namely regarding DETONATION -- that begins at 25:37.

This compares the detonation possibility of 3 fuels... G100UL, UL94, and the Eagle/EBTE. Pretty conclusive IMHO that only G100UL is "detonation-improbable".

As George says, "it's about DATA"... something that GAMI has... and apparently of which the other parties had/have very little. Could it be that GAMI has the most capable aviation piston engine test stand in the country/world?
 
wayneda40 said:
I encourage everyone to view the important part in the video that Martin posted -- namely regarding DETONATION -- that begins at 25:37.

This compares the detonation possibility of 3 fuels... G100UL, UL94, and the Eagle/EBTE. Pretty conclusive IMHO that only G100UL is "detonation-improbable".

As George says, "it's about DATA"... something that GAMI has... and apparently of which the other parties had/have very little. Could it be that GAMI has the most capable aviation piston engine test stand in the country/world?
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I found it interesting that they went to George to do the UND/UL94 testing. That told me they did extensive testing with their own fuel and nobody else was set up for it.
 
Racerx said:
I found it interesting that they went to George to do the UND/UL94 testing. That told me they did extensive testing with their own fuel and nobody else was set up for it.
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Yep. Furthermore, George even has a suggested fix for UND/UL94 (i.e. reduce timing to 20-22 deg). And no one paid GAMI to do this detonation testing of UL94 and Eagle/EBTE!
 
wayneda40 said:
As George says, "it's about DATA"... something that GAMI has... and apparently of which the other parties had/have very little. Could it be that GAMI has the most capable aviation piston engine test stand in the country/world?
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Perhaps that is true within the aviation industry. There are various test facilities around the US that I expect could handle the task of performing the testing, if they were asked to. The question is, have these guys bothered to pursue it?

I’m not trying to downplay GAMI or what capabilities they have, I’m just suggesting that aircraft engines and testing them isn’t anything particularly magic.
 
mondtster said:
Perhaps that is true within the aviation industry. There are various test facilities around the US that I expect could handle the task of performing the testing, if they were asked to. The question is, have these guys bothered to pursue it?

I’m not trying to downplay GAMI or what capabilities they have, I’m just suggesting that aircraft engines and testing them isn’t anything particularly magic.
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Yup.....and when I worked in industry we farmed out R&D engine testing to Rouch. They have very capable engine labs for testing....I'll bet far exceeding George's rigs.
 
NordicDave said:
Yes, the knock sensor has a narrow frequency range of vibration which is masked by other vibrations or "noise" in the system.
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You seem stuck on this topic and I don't think you realize that's not how piezo sensors work. The same noises (aka vibrations) in a car motor are in a tractor/airplane motor. About the only thing that makes airplanes loud is the lack of a muffler (a real muffler) and associated headers/exhaust.

You can tune a piezo to a very specific frequency and ignore all the other sounds, its done all the time with proper high/low pass filters and design of the pickup.

Here's a simple test you can do. Take off your exhaust/muffler on your car. Even with all the new noise, the knock sensors still work.
 
wayneda40 said:
Yep. Furthermore, George even has a suggested fix for UND/UL94 (i.e. reduce timing to 20-22 deg). And no one paid GAMI to do this detonation testing of UL94 and Eagle/EBTE!
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Another point about GAMI having the data. If GAMI is the only one already set up to test the fuel/engine. How are the Gami gas competitors going to test their fuel in the same way?
 
pfarber said:
You seem stuck on this topic and I don't think you realize that's not how piezo sensors work. The same noises (aka vibrations) in a car motor are in a tractor/airplane motor. About the only thing that makes airplanes loud is the lack of a muffler (a real muffler) and associated headers/exhaust.

You can tune a piezo to a very specific frequency and ignore all the other sounds, its done all the time with proper high/low pass filters and design of the pickup.

Here's a simple test you can do. Take off your exhaust/muffler on your car. Even with all the new noise, the knock sensors still work.
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Yep, this. More direct anecdotal info - run the Turbo Buick with an open dump and they are OBNOXIOUS. Knock sensor still works.

Now if the exhaust pipe or something else hitting the floor or frame, or there was a suspension rattle on launch, you’d get a knock indication. In a plane, front wheel shimmy or the mains rolling and shuddering on lift off might trigger one, but easily tuned out or ignored for that split second.
 
When I worked at a refinery, the fuel blenders would send their samples to the onsite lab where we had knock engines to test the octane rating of the blend to clear it for distribution. Super old technology test engines, dinosaur-like (sound familiar?).
 
WDD said:
FAA could simply buy the GAMI formula and make it the approved formula. Someone else said it above - it’s not a technical issue, it’s a paper work / bureaucratic issue.
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Under which law and using what funds??????

FAA cannot go out and just buy the GAMI formula. Just like they cannot just say it is approved. They have to stay within the law and regulations.

So it would take both a change in the law and also funding from Congress specifically for this purpose.
 
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StraightnLevel said:
No, but VP or Swift could...or any other company that has the ability to push it into the market.
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VP or Swift or anyone else could license it today. I suspect their business case for producing UL fuel falls apart if they don't own the IP, and AFAIK GAMI has not even set a price for purchasing the formula.


Pinecone said:
So it would take both a change in the law and also funding from Congress specifically for this purpose.
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Yes it would. BUT, I imagine that if the FAA/EAGLE got over their collective NIH syndrome they could make this happen. They have a mandate to get the lead out of AVGAS, so a report to Congress saying "There is a solution, we've already approved it, but to get it to market we need to purchase the formula for $$$$$ and make it available. It's for the children," would probably get them the necessary money.

They're not really looking for a solution. If they were, they'd be trying to get the solution that already exists (G100UL) into production and to market. Instead they're going to play kick-the-can until the GAMI patents expire.
 
Capt. Geoffrey Thorpe said:
CFR (Cooperative Fuel Research) if memory serves me correctly? Single Cylinder, handle on the side to raise and lower the cylinder? Looked like an antique even back in the '70s...
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It was around 1992 and my memory is in black & white, lol! Yes, there was a way to adjust compression ratio on the fly.
 
JimBirk said:
Here's a link to a YouTube video of George Braly's presentation about G100UL at 2024 Osh. It's a bit long, but it is pretty interesting...in an unleaded kind of way. Thanks Martin Pauly!

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Great video. I do not generally watch long posted videos. This one was worth the time. Hopefully, the distributorship George mentioned near the end will pan out.
 
www.avweb.com

AOPA Baron Wing Stain Traced To Leaking Bladder Patch - AVweb

General Aviation Modifications Inc. (GAMI) says the gunk that smeared the underside of the left wing of the AOPA Beech Baron fuel test bed aircraft at AirVenture originated with a leaky patch in the 50-year-old bladder in the tank. In a report prepared by GAMI, the company said the mechanics...
www.avweb.com www.avweb.com
 
I would think with all the $$s AOPA has in their bank account, they could afford to replace fuel bladders before they are *50 years old*. Maybe I believe in proactive maintenance schedules more than most...
 
Jeff Oslick said:
I would think with all the $$s AOPA has in their bank account, they could afford to replace fuel bladders before they are *50 years old*. Maybe I believe in proactive maintenance schedules more than most...
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Well, yeah, but remember it's not their plane. It was leased for $1 to conduct this G100UL demo.
 
They should have spent another dollar and designed a proper experiment. Off my snarky soap box now…..
 
Jeff Oslick said:
I would think with all the $$s AOPA has in their bank account, they could afford to replace fuel bladders before they are *50 years old*. Maybe I believe in proactive maintenance schedules more than most...
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They had to make Oshkosh......and didn't have time to replace them beforehand.

They rolled the dice....and got snake eyes.
:rolleyes:
 
WDD said:
They should have spent another dollar and designed a proper experiment. Off my snarky soap box now…..
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Got to save money to put gas in that free Extra 300 that they have now ... ;)
 
Too many people are too uninterested in actually collecting the data we need. If we really wanted to know how unleaded fuels perform in a demanding flight environment, a controlled experiment with a large fleet of planes in the same operational environment, some using 100LL (control), some using UL94, and some using G100UL would be conducted, and detailed engine data collected. This would likely uncover systematic issues with fuels. Fueling a single plane with two fuels won't be a statistically significant sample, and running fleetwide uncontrolled experiments won't help, either. Without proper controls, any findings are likely meaningless.
 
chemgeek said:
Too many people are too uninterested in actually collecting the data we need. If we really wanted to know how unleaded fuels perform in a demanding flight environment, a controlled experiment with a large fleet of planes in the same operational environment, some using 100LL (control), some using UL94, and some using G100UL would be conducted, and detailed engine data collected. This would likely uncover systematic issues with fuels. Fueling a single plane with two fuels won't be a statistically significant sample, and running fleetwide uncontrolled experiments won't help, either. Without proper controls, any findings are likely meaningless.
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GAMI has been running a number of airplanes for many years on their fuel. The AOPA Baron is NOT a GAMI fuel test, it is an AOPA demonstration.
 
TCABM said:
I thought that went up for sale recently.
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Shows how much I keep up with AOPA these days. My AI source says it was sold but can't provide information on the details ... :dunno:
 
WDD said:
I would see it as part of development. The money they are spending on EAGLE would fund the experiment for example.
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I've been successfully testing 100LL and 93 E-free Mogas in my current experimantal for 12 years. If these new replacements were available at a reasonable cost a few of us might be willing to give them a bit of scrutiny ... :biggrin:
 
Hasn’t the 100 UL already been tested at a flight school?

BTW, since it already has an STC, doesn’t that mean the nice people at the FAA think it can already be used safely? So the work to show it performs has already been done for the ASTM people. It can be approved anytime that governing body simply declares the formula as an approved standard.

(I think I just restated what has already been posted a million times…..)
 
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WDD said:
Hasn’t the 100 UL already been tested at a flight school?
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That was Swift 94UL that was tested at UND. The "test" was not well run from a scientific perspective. No control group, no baseline data. It was suspended when there was some valve recision.
It was not 100UL and I'm pretty sure GAMI demonstrated the valve issue UND had would not have happened with 100UL.
 
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