Swift 94 fuel fails trial at UND

[Shadrach]

35 minutes ago, 1964-M20E said:

There should be no STC needed.  The FAA needs to blanket approve an appropriate replacement.  As far as GAMI goes I'd take $0.02 to $0.05 licensing fee per gallon for research and profit.

FAA does not have the authority. I believe it would take an act of congress.

I find it appalling that there was no federal framework initiated to deal with approving a “drop in” replacement. It comes as no surprise that providing a solution to the problem proved to be less convoluted than approving the solution. An STC is a lousy solution unless there fed is going to mandate a single formula.

[1964-M20E]

13 minutes ago, Shadrach said:

FAA does not have the authority. I believe it would take an act of congress.

I find it appalling that there was no federal framework initiated to deal with approving a “drop in” replacement. It comes as no surprise that providing a solution to the problem proved to be less convoluted than approving the solution. An STC is a lousy solution unless there fed is going to mandate a single formula.

I agree the process is flawed.  Where are the STCs for 100LL??  
Somewhere in time 100lLL began production and that is what we are using today.  We had other fuels that were out there with more lead and more octane.

[Shadrach]

42 minutes ago, 1964-M20E said:

I agree the process is flawed.  Where are the STCs for 100LL??  
Somewhere in time 100lLL began production and that is what we are using today.  We had other fuels that were out there with more lead and more octane.

100LL predates most of our engines. They were certified with 100LL to ASTM D910 specs. The new fuels work in our engines but do conform ASTM standards. There is no currently no blanket authority to authorize it’s use. Therein lies the problem with blanket approval of a new fuel. They cannot just amend all of the TCDS’s.

[N201MKTurbo]

32 minutes ago, Shadrach said:

100LL predates most of our engines. They were certified with 100LL to ASTM D910 specs. The new fuels work in our engines but do conform ASTM standards. There is no currently no blanket authority to authorize it’s use. Therein lies the problem with blanket approval of a new fuel. They cannot just amend all of the TCDS’s.

I think 100LL started in the late 70s early 80s. Before that we had green gas (100/130). 
 

Most of the TCDS’s I’ve read mention a minimum octane number and then reference either 100/130 and/or 100LL.

I hate to say it, but I was flying when 100LL became widely available. There was no paperwork or STCs, they just said you could use 100LL in place of green gas.

[Shadrach]

58 minutes ago, N201MKTurbo said:

I think 100LL started in the late 70s early 80s. Before that we had green gas (100/130). 
 

Most of the TCDS’s I’ve read mention a minimum octane number and then reference either 100/130 and/or 100LL.

I hate to say it, but I was flying when 100LL became widely available. There was no paperwork or STCs, they just said you could use 100LL in place of green gas.

https://generalaviationnews.com/2015/02/24/the-difference-between-100ll-and-100130ll/#:~:text=And here is where a,engines ARE qualified on 100LL.

And here is where a lot of confusion comes in: 100LL is actually 100/130 low lead avgas as defined by ASTM D-910. Yes, 100LL does meet the 130 rich rating and all other properties of 100/130, except for a limit of 2.0 grams per gallon TEL and a different dye color. So almost all radial engines ARE qualified on 100LL.

[Shadrach]

Just now, bluehighwayflyer said:

Back then there was also red gas, which was called Avgas 80 but I can’t imagine that it’s octane was really that low.  My dad had a Cessna 175 in the 70s that could use it.  It was less readily available than green gas, and a little cheaper, I think. 

Yup. What’s different is that all of these fuels were certified using ASTM D910. It is my understanding that none of the new variants can be certified to that standard..

[N201MKTurbo]

26 minutes ago, bluehighwayflyer said:

Back then there was also red gas, which was called Avgas 80 but I can’t imagine that it’s octane was really that low.  My dad had a Cessna 175 in the 70s that could use it.  It was less readily available than green gas, and a little cheaper, I think. 

That was 80/87 gas. That was why 100LL was developed so they didn’t have to make red gas. It was because the low compression engines would foul their plugs using green gas, so they reduced the lead in the green gas and called it 100LL.

[A64Pilot]

80 Octane was that low, and is more than needed for most.

The low compression engine like the C-85 are Certified for something stupid low like 73 Octane from memory.

Its on the data plate I think.

[N201MKTurbo]

8 minutes ago, A64Pilot said:

80 Octane was that low, and is more than needed for most.

The low compression engine like the C-85 are Certified for something stupid low like 73 Octane from memory.

Its on the data plate I think.

The O300 in my Cessna says min 80 octane on the data plate.

[A64Pilot]

5 hours ago, 1964-M20E said:

There should be no STC needed.  The FAA needs to blanket approve an appropriate replacement.  As far as GAMI goes I'd take $0.02 to $0.05 licensing fee per gallon for research and profit.

We will see who’s right eventually, but I expect the fuel will be a whole lot more than the fuel it replaces as in several dollars per gl.

Arguing about how much it will be before it’s being sold is sort of useless though.

I’m surprised California hasn’t outright banned leaded fuel yet myself. I think they will and when they do we will get an idea what it will cost, of course we will be told it’s so high due to limited refining, it will come way down when it’s made in bulk. It won’t matter if the price isn’t due to Gami but due to price gouging of the supplier, I suspect there will be serious profit taking, time will tell.

It will I think be similar to both alternative fuels that I remember, unleaded was much higher than leaded and ULSD is really nuts, running a $1 a gallon more than gas where regular Diesel if at these prices would have been about a buck a gl less. We were told of course that removing the sulphur wasn’t expensive and there wouldn’t be much price difference, just a little higher was all, but Diesel price has climbed to be way above gas.

People only care about what they pay for gas, where they really should be concerned about Diesel, reason is high Diesel price drives up the price of everything, where gas price doesn’t.

[EricJ]

2 hours ago, bluehighwayflyer said:

Back then there was also red gas, which was called Avgas 80 but I can’t imagine that it’s octane was really that low.  My dad had a Cessna 175 in the 70s that could use it.  It was less readily available than green gas, and a little cheaper, I think. 

There was also 115/145 which was a really, really cool purple color.    I was hoping they'd make the new unleaded stuff the same color, as I don't think 115/145 has been made for a long time, but, alas, it's some other less inspiring color.

 

[A64Pilot]

1 hour ago, N201MKTurbo said:

The O300 in my Cessna says min 80 octane on the data plate.

Attached is the data plate for my C-85. I think that 73 was the standard to Certify to back before WWII, and even in WWII the high performance fighter motors all ran on 87 Octane, then a French guy figured out how to bump it to 100 and the US began refining fuel for the Brits to a new Brit standard of 100 Octane, this boosted the power output of the Merlin by quite a lot, gave them over 30 mph at 10,000 ft

Germans at the time and in actuality fought the whole war on 87 Octane I believe. They had higher but not in enough quantity to be effective

The Brits got the new fuel and the constant speed prop built on the Hamilton Standard design under license literally days before the Battle of Britain, it’s most probable without the prop and fuel the outcome would have been different.

https://www.rsc.org/news-events/articles/2009/05-may/spitfire-fuel/

https://airandspace.si.edu/stories/editorial/better-propellers-few-desmond-cookes-legacy-battle-britain

http://www.warbirdsresourcegroup.org/LRG/fuels.html

Point being even “hot rod” super and turbocharged high performance motors can be operated at lower Octane, but at a lower output.

We could run our angle valves with premium car gas, if we accepted lower margins and the ability to run stupid high cylinder head temps, and at a lower power output, but only for sea level engines, once at roughly 5,000 ft power output would be the same, sea level aircraft wouldn’t lose as much performance as those currently based at 5,000 ft altitude but it would be close.

Unless you introduce ADI, anti detonation injection, then you would get your power back and you only need ADI above 25” MP and it 400 degree cyl head temp, roughly, I don’t know if our angle valves have been tested with ADI or not, the Germans in WWII used it to get high performance with 87 Octane fuel, it’s not a new concept.

 

[N201MKTurbo]

25 minutes ago, A64Pilot said:

Attached is the data plate for my C-85. I think that 73 was the standard to Certify to back before WWII, and even in WWII the high performance fighter motors all ran on 87 Octane, then a French guy figured out how to bump it to 100 and the US began refining fuel for the Brits to a new Brit standard of 100 Octane, this boosted the power output of the Merlin by quite a lot, gave them over 30 mph at 10,000 ft

Germans at the time and in actuality fought the whole war on 87 Octane I believe. They had higher but not in enough quantity to be effective

The Brits got the new fuel and the constant speed prop built on the Hamilton Standard design under license literally days before the Battle of Britain, it’s most probable without the prop and fuel the outcome would have been different.

https://www.rsc.org/news-events/articles/2009/05-may/spitfire-fuel/

https://airandspace.si.edu/stories/editorial/better-propellers-few-desmond-cookes-legacy-battle-britain

http://www.warbirdsresourcegroup.org/LRG/fuels.html

Point being even “hot rod” super and turbocharged high performance motors can be operated at lower Octane, but at a lower output.

We could run our angle valves with premium car gas, if we accepted lower margins and the ability to run stupid high cylinder head temps, and at a lower power output, but only for sea level engines, once at roughly 5,000 ft power output would be the same, sea level aircraft wouldn’t lose as much performance as those currently based at 5,000 ft altitude but it would be close.

Unless you introduce ADI, anti detonation injection, then you would get your power back and you only need ADI above 25” MP and it 400 degree cyl head temp, roughly, I don’t know if our angle valves have been tested with ADI or not, the Germans in WWII used it to get high performance with 87 Octane fuel, it’s not a new concept.

 

Your pokey little C85 only makes 21HP/cylinder. My super high performance O300 makes 24HP per cylinder. That’s why it needs that high test 80 octane.

[A64Pilot]

1 hour ago, N201MKTurbo said:

Your pokey little C85 only makes 21HP/cylinder. My super high performance O300 makes 24HP per cylinder. That’s why it needs that high test 80 octane.

I honestly think the number 80 was used as a cert basis based on fuel availability.

73 wasn’t available, so why cert to a non existent fuel? However I believe at one time it was the standard. I don’t know but it’s my understanding that 73 is just base gasoline without additives, maybe called straight run?

I think but don’t have the books anymore that the R-1340 was initially Certified on 73 Octane and then later on 80 Octane, my assumption so it could pull a little bit more boost maybe? The 1340 unlike the C-85 evolved and went I think from about 400 HP to 600.

But I think the TCDS for a 1340 calls out 80, but used to call out 73.

I don’t know any of this though

 

[Hank]

1 hour ago, A64Pilot said:

Unless you introduce ADI, anti detonation injection, then you would get your power back and you only need ADI above 25” MP and it 400 degree cyl head temp, roughly.

Can you hook up that there fancy injector thing downstream of my carburetor please?

1 hour ago, N201MKTurbo said:

Your pokey little C85 only makes 21HP/cylinder. My super high performance O300 makes 24HP per cylinder. That’s why it needs that high test 80 octane.

The rinky-dink O-360 in my C puts out 45 hp per cylinder. A coworker drives a Chevy Sprint, each of my cylinders is larger displacement than his whole engine. But he enjoys modding the car . . . . 

[Shadrach]

2 hours ago, A64Pilot said:

Attached is the data plate for my C-85. I think that 73 was the standard to Certify to back before WWII, and even in WWII the high performance fighter motors all ran on 87 Octane, then a French guy figured out how to bump it to 100 and the US began refining fuel for the Brits to a new Brit standard of 100 Octane, this boosted the power output of the Merlin by quite a lot, gave them over 30 mph at 10,000 ft

Germans at the time and in actuality fought the whole war on 87 Octane I believe. They had higher but not in enough quantity to be effective

The Brits got the new fuel and the constant speed prop built on the Hamilton Standard design under license literally days before the Battle of Britain, it’s most probable without the prop and fuel the outcome would have been different.

https://www.rsc.org/news-events/articles/2009/05-may/spitfire-fuel/

https://airandspace.si.edu/stories/editorial/better-propellers-few-desmond-cookes-legacy-battle-britain

http://www.warbirdsresourcegroup.org/LRG/fuels.html

Point being even “hot rod” super and turbocharged high performance motors can be operated at lower Octane, but at a lower output.

We could run our angle valves with premium car gas, if we accepted lower margins and the ability to run stupid high cylinder head temps, and at a lower power output, but only for sea level engines, once at roughly 5,000 ft power output would be the same, sea level aircraft wouldn’t lose as much performance as those currently based at 5,000 ft altitude but it would be close.

Unless you introduce ADI, anti detonation injection, then you would get your power back and you only need ADI above 25” MP and it 400 degree cyl head temp, roughly, I don’t know if our angle valves have been tested with ADI or not, the Germans in WWII used it to get high performance with 87 Octane fuel, it’s not a new concept.

 

I’ve been told that IO360s run fine on 93 octane car gas. Perhaps with slightly elevated CHTs. It’s a vapor pressure issue, not a detonation margin issue. I am not speaking from personal experience though. Information came from a forum member that has since become inactive. 
 
I did know a guy with an early C210 that would fill one tank with autogas and the other with 100LL. He would only burn auto gas in cruise.

most NA aviation engines don’t need 100 octane

[Fly Boomer]

3 hours ago, A64Pilot said:

I’m surprised California hasn’t outright banned leaded fuel yet myself. I think they will and when they do we will get an idea what it will cost, of course we will be told it’s so high due to limited refining,

From what I have read, it's not "refined" per se.  It's just a mixture of off-the-shelf hydrocarbons.  The trick was finding the right hydrocarbons and the right ratios.

[N201MKTurbo]

1 hour ago, Fly Boomer said:

From what I have read, it's not "refined" per se.  It's just a mixture of off-the-shelf hydrocarbons.  The trick was finding the right hydrocarbons and the right ratios.

It is still mostly alkylate, just like 100LL it definitely comes from an oil refinery. So do most of the aromatics they mix in to get the octane number they need. 
 

Once it gets into volume production, it doesn’t need to cost significantly more than 100 LL.

[McMooney]

1 hour ago, Shadrach said:

I’ve been told that IO360s run fine on 93 octane car gas. Perhaps with slightly elevated CHTs. It’s a vapor pressure issue, not a detonation margin issue. I am not speaking from personal experience though. Information came from a forum member that has since become inactive. 
 
I did know a guy with an early C210 that would fill one tank with autogas and the other with 100LL. He would only burn auto gas in cruise.

most NA aviation engines don’t need 100 octane

My mooney manual actualy says minimum octane 91/96

 

[A64Pilot]

3 hours ago, Shadrach said:

I’ve been told that IO360s run fine on 93 octane car gas. Perhaps with slightly elevated CHTs. It’s a vapor pressure issue, not a detonation margin issue. I am not speaking from personal experience though. Information came from a forum member that has since become inactive. 
 
I did know a guy with an early C210 that would fill one tank with autogas and the other with 100LL. He would only burn auto gas in cruise.

most NA aviation engines don’t need 100 octane

A College in Tennessee ran a C-310 in the 70’s on what was then called Gasahol for quite a long time, only ran one on it with no adverse effects.

I know because a good friend a Dr Ralph Kimberlin was in the program.

However we have to be careful with comparing Octane, the way car gas is rated is completely different than the way Aircraft fuel is rated, the two numbers that were the standard until 100 LL, the first was in “Aviation lean”, the second higher number was in “Aviation rich”

So I don’t know if there is a correlation or not and if there is, what it is.

Other than knowing what it was called I don’t know the specifics of exactly what lean and rich meant exactly other than the obvious that you have a much greater margin in rich, nor do I know why 100LL has only one number.

A little tough to follow but this fellow knows a lot more than I do.

https://generalaviationnews.com/2017/02/20/the-difficulty-in-determining-rich-and-lean-ratings/

Sounds to me like 93 car gas might be similar to a lean rated 89 Octane Avgas.

I know someone that ran car gas in his Maule a few times, that had a high compression fuel injected IO-540, one side car gas the other Avgas, takeoffs, climbs and landings on Avgas, only issue he had was hot starts, the car gas would vapor lock much worse than the Avgas would if he shut down when running the car gas.

I’m sure the 310 was run richer than normal likely on car gas and assume maybe timing retarded and or restricted MP pressure, but don’t know, just know it was done.

From what I saw there was no cyl head temp difference and the Maule was set to stock timing, but when on car gas restricted to 25” MP.

[A64Pilot]

4 hours ago, Hank said:

Can you hook up that there fancy injector thing downstream of my carburetor please?

It’s even simpler than adding Nitrous as there only needs to be one injector so yes it would be very easy to add an injector plate under a carburetor.

But you may not need it, often carbs go with lower compression engine that have a car gas STC available, sometimes the STC doesn’t require any modification, sometimes it may require an additional fuel pump or maybe additional cooling vents in the cowling. A carbureted Maule for instance requires both.

ADI for GA aircraft was brought back by Peterson of the Autogas STC fame over 40 years ago, but it never caught on, not because it doesn’t work, it does and is safe but because the price difference just wasn’t enough to get people excited.

When 100LL goes away and if the Gami fuel is expensive, I think there will be a renewed interest. So much so that if I were younger I’d seek them out and invest the minute 100LL goes away, because I think it will sell, because I’d bet lunch that the Gami fuel is going to be much more expensive and the airplanes that require it will take a huge hit in value too.

I realize the Gami fuel is nothing more than a proprietary blend of existing “stuff” and I busting the recipe would be easy just by varying something a little, but the STC will prevent competition, that’s the value of the STC to keep someone from making a nearly identical mix with just enough difference to be “different”

I’ve posted this before, it’s not vaporware, it exists there have been STC’s for decades, it’s not even difficult.

https://www.avweb.com/features/the-return-of-anti-detonation-water-injection-adi/

https://www.aviationconsumer.com/uncategorized/airplains-inpulse-adi-mogas-for-big-engines/

[N201MKTurbo]

24 minutes ago, A64Pilot said:

A College in Tennessee ran a C-310 in the 70’s on what was then called Gasahol for quite a long time, only ran one on it with no adverse effects.

I know because a good friend a Dr Ralph Kimberlin was in the program.

However we have to be careful with comparing Octane, the way car gas is rated is completely different than the way Aircraft fuel is rated, the two numbers that were the standard until 100 LL, the first was in “Aviation lean”, the second higher number was in “Aviation rich”

So I don’t know if there is a correlation or not and if there is, what it is.

Other than knowing what it was called I don’t know the specifics of exactly what lean and rich meant exactly other than the obvious that you have a much greater margin in rich, nor do I know why 100LL has only one number.

A little tough to follow but this fellow knows a lot more than I do.

https://generalaviationnews.com/2017/02/20/the-difficulty-in-determining-rich-and-lean-ratings/

Sounds to me like 93 car gas might be similar to a lean rated 89 Octane Avgas.

I know someone that ran car gas in his Maule a few times, that had a high compression fuel injected IO-540, one side car gas the other Avgas, takeoffs, climbs and landings on Avgas, only issue he had was hot starts, the car gas would vapor lock much worse than the Avgas would if he shut down when running the car gas.

I’m sure the 310 was run richer than normal likely on car gas and assume maybe timing retarded and or restricted MP pressure, but don’t know, just know it was done.

From what I saw there was no cyl head temp difference and the Maule was set to stock timing, but when on car gas restricted to 25” MP.

Alcohol usually has pretty high octane. That shouldn’t be a problem with gasohol. The problem is range and system compatibility. Alcohol has about 30% less energy per gallon, so your range will suffer. It will also attack some airplane components, like polysulphide sealant.

[A64Pilot]

Yes alcohol has high octane, (over 110) why a properly designed E85 engine would be higher compression, that helps with the lower energy density of the alcohol, but then it couldn’t burn regular gas. Flex fuel engines are at best a kludge, good for virtue signaling I guess but not much else. I think the auto manufacturers got a tax break

But Gasahol and now E10 and E15 isn’t any higher Octane than gas without it, presumably when they add the alcohol they use cheaper lower octane fuel and end up the same, presumably the profit margin of E10 is higher.

I’m not abdicating burning car gas in aircraft that aren’t STC’d for it, merely pointing out it’s been done before and is in fact done very widely by the Experimental guys that can burn whatever they like.

Years ago I searched the NTSB database looking for accidents that were caused by alcohol in the autogas. I figured there would be several, because no one I knew tested for it even though the test is easy.

I couldn’t find any, doesn’t mean there aren’t but if there are I couldn’t find any, this was about 15 years ago.

I doubt ethanol will eat up fuel tank sealer, but it could. It has eaten up things I didn’t expect like boat fiberglass fuel tanks for instance.

[McMooney]

 

[A64Pilot]

Autofuel has been run pretty much forever in aircraft, even way back before Unleaded and before STC’s.

If your in the Boonies and Avgas wasn’t available and you had to have the Supercub to fly in this Winters meat supply, you burned what there was and then upon discovering nothing happened you may have kept burning it because of the price difference.

But at least since the 70’s when the Autofuel STC’s came into existence many adopted its use for their C-140’s etc which require zero modification for it and the price for the STC if you wanted to be a good guy and legal was $1 a HP, so $85.

There are posts on the C-140 website with numbers that show that the difference in price between the two will pay for an engine overhaul.

So I think it’s been well established that at least for the Conti’s that can burn Autofuel that they can do so safely.

Does that mean that all lead free fuel are good? Who knows.

To be completely honest there are a not small number of guys that fly Experimental that use Autogas and a good grade of Synthetic auto oil without issue. Do I think that’s a good idea? No, because Auto oil isn’t ashless, I think it’s not hurting them because their engines burn little oil, what if they burnt a half a qt an hour? I think carbon deposits would cause a serious problem myself.

Only reason I bring that up is to try to show that a limited trial doesn’t really tell you if something will work in the fleet. Your trial needs to include badly worn but airworthy engines and ones tgat sit for long times etc. Embry Riddle fleet isn’t even close to the average use to say nothing of it doesn’t get cold in Daytona Fl etc.

But in my opinion Auto fuel has been used for so long by so many it’s gone way beyond a limited trial, and it’s been used in just about every environmental condition from the frozen tundra to deserts etc and for decades.

I usually burn auto fuel in my C-140 but often burn 100LL too because filling the 140 from 5 gl cans is a PIA, while I have a 285 gl tank of 100LL with a pump etc in my hangar, it’s just too easy to pull the hose out and fill with LL.

If I had an auto gas tank then I would never burn LL in it.