Why does my POH say to use 91/96 octane avgas

[T. Peterson]

2 minutes ago, A64Pilot said:

There are other issues, first Ethanol is prohibited, and non ETH fuel can be hard to find.

But it’s been years ago but I searched the NTSB database long and hard looking for an accident that the cause was Auto fuel and couldn’t find one, maybe I just wasn’t searching correctly, or maybe they are almost non existent?

Buccee’s has ethanol free…

[A64Pilot]

44 minutes ago, T. Peterson said:

Buccee’s has ethanol free…

You can get it all over Fl too, but a real problem is exactly what is Mogas? It’s chemical composition changes every so often and certainly in most places seasonally, so without an exacting standard Certification may be tough, depending on how much Political will there is in the FAA, they are a Government agency after all.

https://www.epa.gov/fuels-registration-reporting-and-compliance-help/gasoline-properties-over-time

Formulation changes by where you are and what time of year too

https://www.eia.gov/todayinenergy/detail.php?id=11031

Of course California gas is different than everybody else’s

https://ww2.arb.ca.gov/our-work/programs/fuels-enforcment-program/california-reformulated-gasoline#:~:text=As part of an overall,Gasoline requirements in January%2C 1992.

I was forced by a fool to go down a road of trying to Certify our airplane to burn Bio-Diesel, which it would do so happily, but the obvious problem is what is Bio-Diesel?

It’s an undefined product, some of it comes from animal fats, some from several different plant sources, all of it having quite different properties, so how do you certify to something when you don’t know what it is, it can be blends of lots of things too, pretty much anything that’s not Petroleum, is a liquid and burns is labeled  Bio-Diesel.

Only possibility is to Certify to every possibility that it could be, good luck with that.

I did find out in my researching that maybe not unsurprisingly the absolute experts, the people that knew more about it than everybody else combined was John Deere.

That was 15 years or so, back when offset credits were all the rage

 

[Pinecone]

2 hours ago, A64Pilot said:

Chance of pilot running out of oil or fuel? ADI will have low level sensors. Oil doesn’t, even if you did, when the empty light comes on, reduce to 25” MP and return and fill the tank.

ADI operates whenever detonation is possible, above 25” MP and or cyl head temps above 400. For an NA engine that shouldn’t be an issue for cruise. Turbo’s may or may not need another answer. Do you cruise over 25” and or 400 cyl head temp?

The STC shouldn’t be above $5 or 6K as a guess and as there isn’t any kind of patent there would be several STC’s if or once it catches on.

I don’t think there is yet a Mooney STC, just ones for aircraft that often worked where Avgas was scarce, unless it’s changed.

All the time over 25"

I have a turbo.  And I climb at full power to mid-teens, so a lot of ADI fluid.  

So a simple $5K - $6K for the STC.  The GAMI STC is less and an AMU.

And install?

And will all airports have ADI fluid?  How will they handle it?  Mix it?  Get it into the plane?  Or are you going to have to carry extra, like TKS fluid?

[A64Pilot]

2 hours ago, Pinecone said:

All the time over 25"

I have a turbo.  And I climb at full power to mid-teens, so a lot of ADI fluid.  

So a simple $5K - $6K for the STC.  The GAMI STC is less and an AMU.

And install?

And will all airports have ADI fluid?  How will they handle it?  Mix it?  Get it into the plane?  Or are you going to have to carry extra, like TKS fluid?

I don’t know how they will handle a turbo

I’m going to bet you money that when or if the Gami fuel becomes available you’re going to spend more than you think a year on it, every year. 

Install should be dead easy, it’s just a tank with two integral pumps, an MP sensor and cyl head temp sensor, most likely will tie into existing ones as many have one on each cylinder and a control / display box, the mixing / injection plate will be just that, ever install Nitrous on a car?

For most of us NA guys 5 gls of fluid will last a long time, at 5,000 ft we are at 25”MP wide open so above that it’s off, if we climb at only 500 FPM and start at sea level and add 1 min for T/O that’s 11 min at 6 GPH, but you know most will likely do much better, most can beat 500 FPM but that’s about 1 gl, so 5 T/O and climbs? Worst case you only carry the alcohol and oil, at 1% mix the oil is nothing and 40% of 5.5 gls is what? maybe 2 gls. Any airport will have water.

It’s not “special” Aviation alcohol, so yes I’d suspect FBO’s would carry it if there was a demand

If think you will run short soon as you get the gear and flaps up reduce to slightly less than 25” she will climb fine, just a little slower. I reduced my C-210 to 25 squared with flaps and gear up as it was 300 HP for only 5 min, it did just fine, by reducing to 25” your putting the engine at 5,000 ft, a Mooney climbs fine through 5,000.

Best chance we have for keeping prices from going through the roof when LL goes away is to have options.

Plus in a great many countries Avgas simply isn’t available, that’s the biggest reason for the Diesel push, but with ADI you could burn Mogas

So far as finding it, even my local Walmart has it as do a lot of paint stores, even Amazon, if your traveling and need it have Amazon ship it to the FBO your going to, just tell them you have a package coming and you’ll pick it up. I’ve done that a few times for clothes and other stuff.

[cliffy]

ADI was used on big radial engines.   Even on Reno racers to stop detonation at high manifold pressures

On big radials it would also clean out the carbon build up in the cylinder head.

Water injection (plain demineralized water- soft) was used on early passenger jets like the 707s   They had a 600gallon water tank

in the right wheel well to be used on take off to keep the EGT down. 

We called them "Water Bombers"

[47U]

2 hours ago, cliffy said:

We called them "Water Bombers"

As I remember from my SAC days as an alert controller (‘86-‘88), the tankers had 570 gallons demin water and would burn it in about 2 or 2 and one-half minutes.  The exhaust trailed thick black smoke.  Pax who were unfamiliar with a water takeoff would show concern when the acceleration and sound perceptibly decreased when the water injection ran out.

The B-52G had 1195 gallons for its 8 engines.  On alert, when the weather turned cold (around 40 F as I remember), the tanker crew chiefs spent the night running ground power units heating the demin water.  The bombers didn’t have heaters, so two flight crew members (two man policy) had to enter the cockpit and hit the ‘dump’ switch.  The next morning when the temps warmed back up, crew chiefs had to reservice the water tanks.  If you were careful and didn’t waste too much water, you could get two bombers serviced with one water truck.  Myself, having a tanker background, I was cautioned by the bomber guys that if I saw the crew chief on the B-5 stand servicing water in his jet while leaning against the leading edge of the wing, he’s not servicing the water tank, he’s putting water into the forward body fuel tank.  The water tank cap was a few feet forward of the wing leading edge.  A mistake like that would get you immediately fired off the alert pad, never to return, and likely with some negative paperwork on your record.  

What was the saying?  “To err is human, to forgive is not SAC policy.” 

[Pinecone]

10 hours ago, A64Pilot said:

I don’t know how they will handle a turbo

I’m going to bet you money that when or if the Gami fuel becomes available you’re going to spend more than you think a year on it, every year. 

Install should be dead easy, it’s just a tank with two integral pumps, an MP sensor and cyl head temp sensor, most likely will tie into existing ones as many have one on each cylinder and a control / display box, the mixing / injection plate will be just that, ever install Nitrous on a car?

For most of us NA guys 5 gls of fluid will last a long time, at 5,000 ft we are at 25”MP wide open so above that it’s off, if we climb at only 500 FPM and start at sea level and add 1 min for T/O that’s 11 min at 6 GPH, but you know most will likely do much better, most can beat 500 FPM but that’s about 1 gl, so 5 T/O and climbs? Worst case you only carry the alcohol and oil, at 1% mix the oil is nothing and 40% of 5.5 gls is what? maybe 2 gls. Any airport will have water.

It’s not “special” Aviation alcohol, so yes I’d suspect FBO’s would carry it if there was a demand

If think you will run short soon as you get the gear and flaps up reduce to slightly less than 25” she will climb fine, just a little slower. I reduced my C-210 to 25 squared with flaps and gear up as it was 300 HP for only 5 min, it did just fine, by reducing to 25” your putting the engine at 5,000 ft, a Mooney climbs fine through 5,000.

Best chance we have for keeping prices from going through the roof when LL goes away is to have options.

Plus in a great many countries Avgas simply isn’t available, that’s the biggest reason for the Diesel push, but with ADI you could burn Mogas

So far as finding it, even my local Walmart has it as do a lot of paint stores, even Amazon, if your traveling and need it have Amazon ship it to the FBO your going to, just tell them you have a package coming and you’ll pick it up. I’ve done that a few times for clothes and other stuff.

 

Have to mount the tank to FAA specs for a 40 pound item.  Run the tubing and wires, which means pulling a good bit of the interior.  The injection plate will change the angles of the throttle and mixture cables.

It is 60% alcohol and 40% water, so you have to carry 3 gallons per refill.    And typically they use methanol, which has issues with aluminum.

In the old days, when the system was designed, it was common to climb at 25/25.  But these days, the way to do it is full throttle. 

If you buy it by the 55 gallon drum, it is about $9 per gallon.  Plus delivery.   So 3 gallons per tank is $27, divided by 5 TO, is $5.20 per takeoff.  Plus the costs of the system and install.

And this is to use a fuel that is more expensive than 100LL at this time, unless it is subsidized.  Versus buying a $600 STC and burning a 100 UL fuel.  That may cost more at first than 100LL, but many are predicting that since it is blending from components found at any refinery, and not special handling or trucks, it will be blending in more places, and even if the price doesn't go down due to competition, it will reduce transport costs.

 

[A64Pilot]

STC will tell you how to mount it, it’s not harder than batteries which are more dense of course. Your convinced it’s going to be difficult, I don’t think it will be, we will see if it becomes widespread.

I for one can live with 25 Squared, it’s how I flew my 210, but then that may be why I never had any Cylinder problems on the IO-520 either, but again I feel the 500 FPM climb extremely conservative, pretty sure I can get that at 2700 / 25” and use no ADI.

The little bit of oil deals with Methanol corrosion, this isn’t new and un-proven, it’s been around since the 1930’s and widely used in WWII and after and sort of fell out of use when big high performance radials went away

Just call me extremely suspicious of what the Gami fuel will cost, I believe if LL is banned and it’s the only option there will be quite a lot of profit taking, like trying to buy a chain saw of generator after a hurricane, after all the developer isn’t the one making or selling it is he?

In fact I don’t expect to see it until LL is banned, then we will know what it costs

Why would 94UL cost more than 100LL if it’s not subsidized? It’s just 100LL without the lead? Does it cost more to not put the lead in?

But if it does then Premium auto fuel is an option. I run auto fuel in my 140 and it’s not bad, no worse than the lawnmower that sits over winter.

I think just like when LSA first became a thing that aircraft that can burn Auto fuel will quickly become in short supply and be overpriced when and or if LL goes away.

That’s when I bought my 140, pretty much overnight when LSA became real, 140’s which had been since they were first built the most expensive of the little airplanes dropped in value drastically, because they weren’t LSA legal, so I bought mine for a song.

[T. Peterson]

I highly discourage anyone from using Buccee’s ethanol free 91 octane in their airplane. It can prove very dangerous to your health. I don’t know if my back will ever recover from toting and pouring all those 5 gallon buckets!

[Pinecone]

22 hours ago, A64Pilot said:

STC will tell you how to mount it, it’s not harder than batteries which are more dense of course. Your convinced it’s going to be difficult, I don’t think it will be, we will see if it becomes widespread.

Just call me extremely suspicious of what the Gami fuel will cost, I believe if LL is banned and it’s the only option there will be quite a lot of profit taking, like trying to buy a chain saw of generator after a hurricane, after all the developer isn’t the one making or selling it is he?

In fact I don’t expect to see it until LL is banned, then we will know what it costs

Why would 94UL cost more than 100LL if it’s not subsidized? It’s just 100LL without the lead? Does it cost more to not put the lead in?

But if it does then Premium auto fuel is an option. I run auto fuel in my 140 and it’s not bad, no worse than the lawnmower that sits over winter.

I think just like when LSA first became a thing that aircraft that can burn Auto fuel will quickly become in short supply and be overpriced when and or if LL goes away.

That’s when I bought my 140, pretty much overnight when LSA became real, 140’s which had been since they were first built the most expensive of the little airplanes dropped in value drastically, because they weren’t LSA legal, so I bought mine for a song.

But the battery mount was designed into the airplane.  This is not.  And you will need mounts designed and engineered for every make and model you intend to use it on.  Who has the cash to do that?

The good thing about GAMI fuel is, ANY refinery can blend it from things that it already makes.  So refinery A raises price too high, refinery B starts to make it and you have a price war.  The problem with 100LL is the Lead makes things more complicated.  You have to buy the TEL, store it, handle it, keep is segregated from everything, and everything it touches is either dedicated to it or has to be cleaned and decontaminated.  And the same for the trucks delivering it.

94UL is more expensive because you have to put in another whole fueling system, and then you are selling a lot less of the fuel.   And it has be to delivered by different trucks than the 100LL due to contamination.

Mogas has its issues.  Not everywhere has easy to find ethanol free fuel.  And it is not as tightly controlled as AVGAS, so this tank is not the same as the last one. 

[A64Pilot]

IF LL is outlawed, then there will be a big demand for 94UL because the majority of the fleet can use it, and like I said if we don’t get stupid it can go into the old LL supply system, tanks, trucks etc. Just as I’m sure the Gami fuel could. Pretty quickly nearly all the lead will be gone, best way to get rid of it would be to burn it, but if we get stupid and require some kind of extensive decontamination, replacement of hoses etc, what do you do with all the contaminated stuff, to say nothing of the expense.

What I think may happen is a return to two fuels, 94UL and the Gami, because I think the Gami won’t be as cheap as many think. But many of the lower compression motors can burn Auto fuel now, so we will see if 94UL has a place or not.

94UL on the other hand if in fact it’s simply 100LL without the lead, everything is in place for it, production, transportation, storage, dispensing etc. just don’t put the lead in it, start delivering it tomorrow 

Leaving the high compression motors and turbos requiring either ADI or the Gami fuel. From years ago even though only a fraction of the fleet need the high octane stuff, they burn the majority of the fuel.

We will see what happens

[A64Pilot]

20 hours ago, T. Peterson said:

I highly discourage anyone from using Buccee’s ethanol free 91 octane in their airplane. It can prove very dangerous to your health. I don’t know if my back will ever recover from toting and pouring all those 5 gallon buckets!

I had a 100 gl tank in the bed of my truck, I fueled my 140 with it and the Center Console boat I kept at the Naval Warfare Center in Panama City Fl.

If you run the numbers on the price difference in 100 LL and car gas if you only burn car gas at least for a C-85 the money saved will pay for an overhaul, it’s not insignificant.

The little motors like the C-85 actually seem to run better on car gas and don’t foul plugs etc.

Min octane fuel for the C-85 and even most models of the Supercharged R-1340 is 73 Octane. Quite a few of the very old designs don’t require high Octane fuel, because I don’t think it existed back then, 100 Octane didn’t become available until well into WWII I believe. The 1340’s that can’t use 73 Octane require 80 Octane, which I’m sure car gas meets. Remember car Octane and Aviation don’t directly correlate.

Without the US made 100 Octane fuel it’s likely the Battle of Britain may have had a different outcome, and it most likely would have been lost too except for the license built Hamilton Standard props fitted to the Spits at the last minute. Without those two things the Me-109 outperformed the Spits.

https://www.rsc.org/news-events/articles/2009/05-may/spitfire-fuel/#:~:text=The 100-octane fuel that,London and south-east England.

Most of WWII aircraft fought the war with 87 Octane fuel. The Me-109 could only produce 1600 HP without ADI, but ADI took it to over 2,000 HP, 500 additional HP.

Interesting a lower percentage of Alcohol, 30% gave the best power, 50% was used mostly for its lower freezing point, which I assume in a Russian Winter was important.

https://en.wikipedia.org/wiki/MW_50