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Posted

There is a good article in this month's Aviation Consumer about G100UL and what the STC means. Basically it says that per the General Counsel's "Busch Letter' an STC is the final word on the suitability of a product to be used and that Lycoming's "might not warranty" is BS because the FAA has said the fuel meets the requirement of the Certificate Holder's specifications on the engine, even if the type certificate holder does not specify or agree. They went on to note that airframe manufactures tried the same weasel words with VG mounted on the wing and that did not work either because as long as the airframe (or engine) was used within the parameters of the TCDS the STC would have no effect upon its viability, parameters or service life.

  • Like 2
Posted
1 hour ago, Shadrach said:

One thing is obvious from this thread. There are a lot of uninformed folks regarding the process and approval. Every one is entitled to an opinions no matter how uninformed. 

Interesting how you view anyone that disagrees with you as uninformed.

You can keep wordsmithing what ASTM standard means, but as long as Lycoming isn't buying in, then neither am I.  When your engine manufacturer won't stand behind the fuel you want to use that is NOT a good thing.  Regardless of what your personal view is on why they will not.

Did you read the NATA link that N201MKTurbo provided?  Apparently they are as 'uninformed' as I (and Lycoming) am since they pretty well stated my exact position on this!

It's been obvious that neither one of us is going to convince the other.  Gentle readers can decide for themselves which of our arguments are more persuasive.  This will play out how it plays out, despite how we may think it should!

What I can't understand is how anyone thinks a SINGLE, FORCED, fuel is going to be the better solution for any of us.

As for the last word, you can have it. @BlueSky247 has it right: This horse is dead!

  • Like 1
Posted
13 hours ago, Shadrach said:

Ok then, this begs the question what would be satisfactory? The fuel has 100s if not 1000s of hours of testing on the most sophisticated aviation engine test stand available...anywhere.  It has gone through two STC applications and met all standards for approval each time through two different FSDOs.
No one here has articulated an actual technical concern with the fuel, just concerns about product development as a process in general. Either there is a standard or there isn’t. If there is, either that standard has been met or it hasn’t. In this case there is a standard for STC approval. If one has an issue with said standard or the process in which approval was granted, then make it known.  “I am sure there is something wrong with it because there have been things wrong with other things at other times that I have observed ” is a lousy argument.

I would love to see the G-1 and what Gami showed compliance to.  

  • Like 2
Posted
8 hours ago, MikeOH said:

What I can't understand is how anyone thinks a SINGLE, FORCED, fuel is going to be the better solution for any of us.

It will be better if you are willing to pay the overhead airports and FBO's have to pay to maintain two dispensing systems. You think Avgas is expensive now, wait until you have that kind of capital investment. I don't think you have really thought this out. New tanks, new dispensing equipment, double the number of trucks. Oh yeah it would be in the billions. Even worse, you would be amortizing that equipment investment over half the gallons, because while the total demand has not changed, you have double the equipment.

Lycoming can wail all they want, but they told the FAA when they got a TCDS what they expect in exacting terms of fuel and the FAA took them at their word. When a fuel came along that was not on the TCDS but met all of Lycoming's expectations it informed the FAA during certification of their engine, the FAA said yes. Unless Lycoming wants to go back and amend their TCDS to specifically say "this fuel, with this formulation will not be used" then the STC stands. Further in doing so, Lycoming will have to explain why so that the FAA can exclude other STC applicants and amend their process which is a very, very tall order because it will basically upend the certification of all their engines, and they know it.

  • Like 1
Posted
16 hours ago, EricJ said:

Storage and material compatibility has been mentioned a number of times, and George has said that it may be an issue.

Storage?  A current thread on BT discusses this.  They had a number of drums, one opened, but capped, that were sent to ER in FL and sat for several years before being returned to GAMI.  The ONLY change (yes, they did lab analysis on them) was the opened drum had lost a bit of vapor pressure.  That could make a very low temp start a bit harder.

Material?  They have tested in several wet wing aircraft.  And they tested bladders and no issues.

George may be a salesman, but he is a pilot first.  And if there are any hidden issues, they are because no one has looked for them or seen them.  I cannot see him putting out a product with any known issues.

Posted
On 8/8/2024 at 10:14 AM, Pinecone said:

Storage?  A current thread on BT discusses this.  They had a number of drums, one opened, but capped, that were sent to ER in FL and sat for several years before being returned to GAMI.  The ONLY change (yes, they did lab analysis on them) was the opened drum had lost a bit of vapor pressure.  That could make a very low temp start a bit harder.

Material?  They have tested in several wet wing aircraft.  And they tested bladders and no issues.

George may be a salesman, but he is a pilot first.  And if there are any hidden issues, they are because no one has looked for them or seen them.  I cannot see him putting out a product with any known issues.

Indeed this is specifically addressed in the GAMI FAQ section. Of course, one would have to believe that GAMI is representing the test results accurately which is questionable given that the owner is “essentially a Salesman” and an “Attorney”.  I mean think of all the shady stuff that GAMI has done in the last 30+ years and then couple that with all of the compelling evidence presented in this thread. 

Posted
2 hours ago, Pinecone said:

Storage?  A current thread on BT discusses this.  They had a number of drums, one opened, but capped, that were sent to ER in FL and sat for several years before being returned to GAMI.  The ONLY change (yes, they did lab analysis on them) was the opened drum had lost a bit of vapor pressure.  That could make a very low temp start a bit harder.

Material?  They have tested in several wet wing aircraft.  And they tested bladders and no issues.

George may be a salesman, but he is a pilot first.  And if there are any hidden issues, they are because no one has looked for them or seen them.  I cannot see him putting out a product with any known issues.

George's response on the BT thread is very enlightening. 

Posted
2 hours ago, Pinecone said:

Storage?  A current thread on BT discusses this.  They had a number of drums, one opened, but capped, that were sent to ER in FL and sat for several years before being returned to GAMI.  The ONLY change (yes, they did lab analysis on them) was the opened drum had lost a bit of vapor pressure.  That could make a very low temp start a bit harder.

Storage includes the material compatibility in the trucks and vendor tanks, and all of the related equipment including pumps,  gaskets, hoses, valves, etc.   Basically everything that could be exposed to the fuel for long periods.  Vendors and distributors don't want to pay to replace or update equipment, nor do they want additional maintenance issues or surprises down the road.   Because the aromatic components are different in G100UL there are significant and real concerns.  George has said this publically and said it at the event I attended at Buckeye.

2 hours ago, Pinecone said:

Material?  They have tested in several wet wing aircraft.  And they tested bladders and no issues.

A few item tests aren't conclusive and "test it in the field" isn't what most of the community or regulators are looking for, and especially not the distributors and vendors.   I suspect this may be one of the bigger barriers, but we really don't know.   The AOPA Baron had a tank patch fail in the bladders on the side holding G100UL, but it isn't known whether or not this was related to age or the G100UL.   In any case, it's not true that there have been "no issues".

Posted
2 hours ago, Shadrach said:

Indeed this is specifically addressed in the GAMI FAQ section. Of course, one would have to believe that GAMI is representing the test results accurately which is questionable given that the owner is “essentially a Salesman” and an “Attorney”.  I mean think of all the shady stuff that GAMI has done in the last 30+ years and couple that with all of the compelling evidence presented in this thread. 

I hope that you would have posted that in Green on BT, :D

 

  • Haha 1
Posted
1 hour ago, EricJ said:

Storage includes the material compatibility in the trucks and vendor tanks, and all of the related equipment including pumps,  gaskets, hoses, valves, etc.   Basically everything that could be exposed to the fuel for long periods.  Vendors and distributors don't want to pay to replace or update equipment, nor do they want additional maintenance issues or surprises down the road.   Because the aromatic components are different in G100UL there are significant and real concerns.  George has said this publically and said it at the event I attended at Buckeye.

A few item tests aren't conclusive and "test it in the field" isn't what most of the community or regulators are looking for, and especially not the distributors and vendors.   I suspect this may be one of the bigger barriers, but we really don't know.   The AOPA Baron had a tank patch fail in the bladders on the side holding G100UL, but it isn't known whether or not this was related to age or the G100UL.   In any case, it's not true that there have been "no issues".

Hmm, GAMI has had G100UL in their fueling rig for many years.  Plus in planes.

And it seems you don't really understand accelerated testing.  BTW, typically done to ASTM standards.

Let's see, do bladder patches fail?   YES.  Have other test aircraft had patched bladders, that one I don't know.  But the Baron bladders were planned on being replaced before they started the demo (it is not really a test), but they were back ordered.

Posted
21 minutes ago, Pinecone said:

Hmm, GAMI has had G100UL in their fueling rig for many years.  Plus in planes.

And it seems you don't really understand accelerated testing.  BTW, typically done to ASTM standards.

Let's see, do bladder patches fail?   YES.  Have other test aircraft had patched bladders, that one I don't know.  But the Baron bladders were planned on being replaced before they started the demo (it is not really a test), but they were back ordered.

It looks to me like all of the supposed “issues” are non-specific. 

Posted
45 minutes ago, Pinecone said:

And it seems you don't really understand accelerated testing. 

I do.

Posted
1 hour ago, Brandt said:

So, I am going to ask what is maybe a dumb question.  But it occurred to me as I was reading the Car and Driver article on the new Corvette ZR-1 with 1064 horsepower and 20 psi of boost running on 93 octane unleaded that it doesn’t have a detonation problem. I assume this is achieved through a knock sensor that adjusts timing.

If I am correct, does that mean the only reason we need 100 octane fuel, whether leaded or not, is due to the lack of variable timing and a knock sensor? Or am I missing something here.

As I am being vulnerable here, be gentle….

 

So, once again you cannot compare car engines with aircraft engines. For one thing, if you could get that 1064 HP continuously, which would be very difficult, it would overheat within a few minutes. And if you could keep it making that HP without overheating, it would probably self destruct in short order.

The real question is what HP will that engine make continuously in its installed configuration? You have to realize that a Corvette probably takes less than 30 HP to run down the freeway at 70 MPH. Another question is, what HP will that engine make at 2700 RPM? That is what it has to do to drive a propellor without a gearbox. Gearboxes have proven to be delicate and unreliable. I actually just found it, it makes 300 HP at 2700 RPM. I wonder what the weight of that engine is with all its accessories and full cooling system? I bet it’s a lot more than our engines.

 

Could somebody take something like an IO470 and make it into a very reliable 200 HP engine that would run on UL94 without issue. That would be easy. One thing you cannot do is take a high performance engine like the IO360 and get 200 continuous HP out of it with UL94. It just cannot be done. You might get an IO390 to make 200 HP with UL94.
 

Contrary to popular opinion, our engines are highly refined and very high performance. The power to weight ratio and BSFC are unequaled by modern auto engines. 

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Posted
1 hour ago, Brandt said:

Thanks for the response, but I think we are talking past each other a little.  My question focuses on the causes of detonation, not continuous power output.  I understand octane rating is a measure of resistance to combustion and octane in conjunction with lowered compression ratios in turbo engines are two key factors in preventing detonation. I believe ignition timing is the other factor.  So assuming you already have a lowered compression ratio, can timing changes t least in part replace the need for higher octane?

If you read all the posts in this thread, your questions will be answered.

Posted
On 8/7/2024 at 9:42 PM, GeeBee said:

There is a good article in this month's Aviation Consumer about G100UL and what the STC means. Basically it says that per the General Counsel's "Busch Letter' an STC is the final word on the suitability of a product to be used and that Lycoming's "might not warranty" is BS because the FAA has said the fuel meets the requirement of the Certificate Holder's specifications on the engine, even if the type certificate holder does not specify or agree. They went on to note that airframe manufactures tried the same weasel words with VG mounted on the wing and that did not work either because as long as the airframe (or engine) was used within the parameters of the TCDS the STC would have no effect upon its viability, parameters or service life.

Has Lycoming ever stated that using mogas under the Peterson STC is grounds for denying warranty claims? If not, then one must wonder why?  

  • Like 1
Posted
13 hours ago, N201MKTurbo said:

... Another question is, what HP will that engine make at 2700 RPM? That is what it has to do to drive a propellor without a gearbox. Gearboxes have proven to be delicate and unreliable. I actually just found it, it makes 300 HP at 2700 RPM. I wonder what the weight of that engine is with all its accessories and full cooling system? I bet it’s a lot more than our engines.

And another issue this presents even if it did work as good or better (which in our case did not) is when you run a car engine at its optimum RPM for max HP it is high reving which in short bursts like quick acceleration, or drag racing is acceptable to hear and feel. But in an airplane trying to fly it at 65 to 75% power feels like going down the highway at 70mph stuck in second gear! And after just 20 mins is exhausting!  My dad built an RV-7 and decided to put a Subaru water cooled fuel injected car engine as the power plant. It looked awesome on paper who would not want optimal fuel management controlled by an ecu to get the best fuel consumption per mile possible without worrying about hot cylinders in the climb and not shock cooling in the descent all on cheap no lead auto gas. Problem was to get 75% power the engine was turning at 6000 rpm! If we tried to get the rpm’s down to 3000 the speed dropped off alot.  The only good effect of this setup is i could always tell when dad was in the pattern as it sounded like an indy 500 race car speeding by. There is something relaxing to engine turning at less than 3000 maybe because all our cars do this at cruise and we just grew up hearing this as normal. Even the Nissan CVT transmission when it first came out would let the engine rev to 6500 and hold it there continuously while adjusting the transmission as the car accelerated. Problem was it felt like and sounded like someone just slipping a clutch as the car accelerated. Nissan solution was to put in rpm changes so that it felt like shifting gears, sacrificing efficiency for more normal sounding engine RPM increases instead of a pegged steady 6500RPM. 

  • Thanks 1
Posted
15 hours ago, N201MKTurbo said:

So, once again you cannot compare car engines with aircraft engines. For one thing, if you could get that 1064 HP continuously, which would be very difficult, it would overheat within a few minutes. And if you could keep it making that HP without overheating, it would probably self destruct in short order.

The real question is what HP will that engine make continuously in its installed configuration? You have to realize that a Corvette probably takes less than 30 HP to run down the freeway at 70 MPH. Another question is, what HP will that engine make at 2700 RPM? That is what it has to do to drive a propellor without a gearbox. Gearboxes have proven to be delicate and unreliable. I actually just found it, it makes 300 HP at 2700 RPM. I wonder what the weight of that engine is with all its accessories and full cooling system? I bet it’s a lot more than our engines.

 

Could somebody take something like an IO470 and make it into a very reliable 200 HP engine that would run on UL94 without issue. That would be easy. One thing you cannot do is take a high performance engine like the IO360 and get 200 continuous HP out of it with UL94. It just cannot be done. You might get an IO390 to make 200 HP with UL94.
 

Contrary to popular opinion, our engines are highly refined and very high performance. The power to weight ratio and BSFC are unequaled by modern auto engines. 

I actually dug up the HP and Torque curves for the naturally aspirated 2024 C8. Output is remarkably close to the IO360 at 2700. That’s where the similarities end. The LT2 is 170lbs heavier than the angle valve Lycoming IO360 and 210lbs heavier than a parallel valve O360. I don’t have the Chevy’s fuel specifics, but I can say with confidence they’re not as good as the Lycoming.

 

 

IMG_0433.jpeg.3db1df68f4efbedc80214a290d3a75f9.jpeg

 

Posted
59 minutes ago, Shadrach said:

I actually dug up the HP and Torque curves for the naturally aspirated 2024 C8. Output is remarkably close to the IO360 at 2700. That’s where the similarities end. The LT2 is 170lbs heavier than the angle valve Lycoming IO360 and 210lbs heavier than a parallel valve O360. I don’t have the Chevy’s fuel specifics, but I can say with confidence they’re not as good as the Lycoming.

 

 

IMG_0433.jpeg.3db1df68f4efbedc80214a290d3a75f9.jpeg

 

I actually got my numbers from the 750 HP LT-1

Posted

I for one am excited to try G100UL.  Having read all that I can find on it, and watching about every George Braly video on youtube, I actually believe what's he's saying.  I am an engineer, and like others here am naturally skeptical about any new shiny object.  But, I'm also able to follow the science, and truly believe that a crankcase and oil will be MUCH cleaner without burning TEL.  Thus I believe that oil changes and overhauls will become less frequent.  

And let it be known I generally don't trust 3 letter govt agencies, but the fact that two FAA field offices approved G100UL after each of them went through ALL of the testing criteria, I'll admit to being impressed.  And I'm also impressed with the amount of testing that GAMI has done for over a decade, and nobody disputes that they have the best aviation fuel testing rig known to man.  I'm impressed that the fuel that has been stored for years works perfectly.  I'm impressed with the fungibility of the product, and the materials testing.

I'm not concerned with the lack of "standards", knowing how such standards work.  I've been involved in standards work with software many times over my career.  You can't miss the hatred of GAMI that oozes out of almost everything that PAFI and EAGLE put out in their press releases.

I expect that only FBOs in CA and those that operate at fields where there is another provider of fuel will be willing to provide G100UL until they are forced by the all powerful Federal Govt to stop selling 100LL, but when an FBO within a reasonable distance sells G100UL, I'll go out of my way to support them.  I understand that G100UL will cost more, but it wouldn't surprise me if the price doesn't drop dramatically when there are multiple producers, distributors, and sellers of the fuel.  That's just how competition and free markets are supposed to work.

I guess all of this makes me a fan boy.

Ute

  • Like 1
Posted
45 minutes ago, N201MKTurbo said:

I actually got my numbers from the 750 HP LT-1

???? That is not a number that I have seen published for a production LT1

Posted
2 hours ago, UteM20F said:

I for one am excited to try G100UL.  Having read all that I can find on it, and watching about every George Braly video on youtube, I actually believe what's he's saying.  I am an engineer, and like others here am naturally skeptical about any new shiny object.  But, I'm also able to follow the science, and truly believe that a crankcase and oil will be MUCH cleaner without burning TEL.  Thus I believe that oil changes and overhauls will become less frequent.  

And let it be known I generally don't trust 3 letter govt agencies, but the fact that two FAA field offices approved G100UL after each of them went through ALL of the testing criteria, I'll admit to being impressed.  And I'm also impressed with the amount of testing that GAMI has done for over a decade, and nobody disputes that they have the best aviation fuel testing rig known to man.  I'm impressed that the fuel that has been stored for years works perfectly.  I'm impressed with the fungibility of the product, and the materials testing.

I'm not concerned with the lack of "standards", knowing how such standards work.  I've been involved in standards work with software many times over my career.  You can't miss the hatred of GAMI that oozes out of almost everything that PAFI and EAGLE put out in their press releases.

I expect that only FBOs in CA and those that operate at fields where there is another provider of fuel will be willing to provide G100UL until they are forced by the all powerful Federal Govt to stop selling 100LL, but when an FBO within a reasonable distance sells G100UL, I'll go out of my way to support them.  I understand that G100UL will cost more, but it wouldn't surprise me if the price doesn't drop dramatically when there are multiple producers, distributors, and sellers of the fuel.  That's just how competition and free markets are supposed to work.

I guess all of this makes me a fan boy.

Ute

This is pretty much sums up my take. 

It's been said many times that Ayn Rand wrote cartoonishly idealist heroes into her novels (I tend to agree), but that her villains were real.  I can see a touch of Randian drama playing out in this initiative.

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Posted
52 minutes ago, Shadrach said:

???? That is not a number that I have seen published for a production LT1

Not sure which engine it was from. I quit paying attention to cars when I started flying.

It was some 750 HP Corvette engine. Here is the one for the big one.

 

065 2025 Chevrolet Corvette ZR1 LT7 Engine Power Torque Curves

Posted
23 minutes ago, N201MKTurbo said:

Not sure which engine it was from. I quit paying attention to cars when I started flying.

It was some 750 HP Corvette engine. Here is the one for the big one.

 

065 2025 Chevrolet Corvette ZR1 LT7 Engine Power Torque Curves

Forced induction is a hell of a drug... That powerband is insane. A step from 2500-3000 and a consistent pavement peeling pull all the way to 7000 with a drop off back under 900hp near redline.

Posted
26 minutes ago, N201MKTurbo said:

Not sure which engine it was from. I quit paying attention to cars when I started flying.

It was some 750 HP Corvette engine. Here is the one for the big one.

 

065 2025 Chevrolet Corvette ZR1 LT7 Engine Power Torque Curves

Is it typical for the torque curve to be so flat?

Posted
15 minutes ago, Shadrach said:

Forced induction is a hell of a drug... That powerband is insane. A step from 2500-3000 and a consistent pavement peeling pull all the way to 7000 with a drop off back under 900hp near redline.

I imagine the flattening of the torque curve is where the boost controller kicks in.

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