kevinsky18

kevinsky18

Well Known Member
I?m getting a bit tired of the whole "when 100LL" disappears scare. This chicken little, "the sky is falling" syndrome needs a bit of check and balance.

Yes there is an environmental concern and yes people would like to see all leaded gas removed. However that?s not going to happen anytime soon in the aviation community.

First environmentalists are mostly focused on over all carbon emissions. 100LL is only a minor part of that when compared to all the gas driven vehicles out there. In other words we are very small blip on their radar.

Second, every gas piston airplane engine uses lead gas. Therefore in order to get rid of it there would have to be an official announcement with at least a ten year grace period.

Third, as most know lead is not just an octane boaster it is also a lubricant for these engines. Even if you have low compression pistons, if lead is removed no aircraft engine will be getting the lead lubrication that it needs. In other word everyone is in trouble not just the high compression engines.

Fourth there are lots of additives out there to boast octane so that?s the least of anyone?s worries if or when lead is removed from aviation fuel. Everyone?s biggest worry is going to be lubrication and this can?t be made up by adding another quart of oil that?s a different kind of lubrication all together.

Fifth and this is very important. If lead was removed from aviation engines every certified engine would become decertified, period! There is no way that Lycoming or Continental would continue to say our engines are going to make TBO. Their response would be plain in clear, ?We can no longer reliably predict the life and reliability of our engines, either discontinue use of the engine or fly at your own risk.? And there are far too many vested interests in certified engines to let that happen: From the engine makers themselves, to airplane manufactures that use these engines to the hundreds of thousands of owners both commercial and private that would no longer have a certified aircraft.

People will say but car engines run just fine without lead. Yes today car engines are designed to run without lead. But older engines suffered consequences when the conversion was made years ago.

For a good example look at NASCAR they are having troubles converting from leaded race gas to unleaded and they are blowing engines in record numbers. But of all the troubles they are having getting the gas to the proper high octane they need is not one of them, it?s lubrication.

Will lead one day be removed from aviation fuel? Yes one day it will happen but when that day comes all leaded gas engines are in trouble not just high compression engines. If you want to be future safe then you need to be looking at alternatives; car engine conversions, turbines or certified aviation diesels.

I believe the aviation diesel engines will be the ones left standing when lead is removed. As it?s over all a better more efficient principle, runs on jet fuel and the cost of developing a diesel engine would be the same as developing an unleaded gas powered engine. And as far as I know there are a number of certified diesel engines flying already and I?m not too sure if there is even one certified unleaded gas engine even on the design table.

So for now I?m going to run high compression and not even think about the ?what ifs? of lead being removed. I?m betting that my engine will be well beyond TBO by the time that happens and I?ll have ordered a diesel retrofit.
 
I appreciate your comments, but the attack and prohibition of leaded fuel is a "when" not "if" situation. my bet is within 10 yrs
 
All the TEL eggs in one basket

I have heard, and I'm happy to be corrected, that there is only one plant in the whole world producing TEL now - based somewhere in the Midlands, in the UK and run by Associated Octel, I believe.

Now, that's a bit of an 'eggs in one basket' scenario, isn't it? There only has to be a bit of an environmental upset there and the place may get shut down. It will put a hole in the AVGAS supplies - already a bit random within Europe - in short order.

Anyone know anything to the contrary?

A
 
Money not lubrication

The issue with conversion is going to be driven by money, period, end of sentence! The current fight is motivated by money. Tomorrow's objections will be motivated by money. It will cost to have an airplane function differently than they currently do. Whether that means changing minor things like gaskets and seals that will cost a few hundred dollars or whether that means changing major things like a new engine in an old airframe that will take tens of thousands of dollars.

The lubrication issue may be the relevant technical problem to overcome but the fight will be against spending all of that money to make the change happen. That is where the true resistance to the change will come from. The auto industry rebelled against the changes but in the end the change occurred. And may I add, I believe for the better. The tide was turned after much government pushing of the large corporations in that industry. That will eventually happen in this industry too. The difference is going to be how tightly the existing pilots and owners of current aircraft are going to hold on to their wallets.
 
Lead= lubrication?

I highly doubt it. I think this is an OWT (old wives tale). This may have been true 20 years ago when soft valve seats were the order of the day but todays Lycomings (and clones) all have hard valve seats, thats why the clone suppliers are saying "yes" to premium unleaded.

I agree for some really ancient engines (I'd pity the radial engine owners) with the old soft valve seats it would be an issue...Nothing that can't be resolved with a simple AD right?...:)

Frank
 
This thread may set records...

Others will certainly comment on the lead as lubricant issue...

My angle is more political - There may be billions of dollars worth of engines which would be "decertified" if LL went away, but that is a spit in the ocean when it comes to national politics. Technical accuracies are obviously not part of national politics, as many examples can prove.

Everything will come down to how much money aircraft interests can send to politicians to keep the inevitable ban on lead from happening sooner rather than later. And, not just how much money, but how much compared to the environmental lobby. And, given recent events, the courts may simply mandate lead's removal without concern for Congress or the citizens. This will be a formidable effort....

Thankfully, most RV's will probably be happy with autogas.
 
Low Pass said:
I appreciate your comments, but the attack and prohibition of leaded fuel is a "when" not "if" situation. my bet is within 10 yrs
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I agree. It's not a question of when. So, we need to plan for the disappearance of 100LL sometime in the future. 10 yr is a good guess.

However, as others have noted, it all comes down to money. It's entirely possible that we could see a different tax on 100LL than MoGas / UL96. Another possibility is that the price of TEL goes up. But MoGas is normally cheaper than AvGas most places, so there is already a reason to use MoGas.

Lots of new aircraft engines run fine on MoGas / 96UL. Many Superior and other LyClones like MoGas, including the certified Vantage engines from Superior. Many "alternative" engines run better with MoGas, e.g., Rotax 912 series. Heck, Formula 1 runs with 102 octane (RON figure, measured just like AvGas), and they get ~800Hp out of 2.4 liters... Lead in fuel is not a limiting problem in engine design.

So, we can wait and fight/delay/deny or we can prepare. I've voted with my money and have a MoGas-compatible airplane. My next one will be too.
 
MoGas compatible

I bought my Superior engine because it was approved for 91 octane Mogas just in case. Then they promptly added Ethanol to all gas sold in Texas. Killed that one off before I ever even tried it!
 
Hmm yeah

Still have not heard an argument that makes sense as to why you can't have ethanol mixed with the gas....Not extolling this as a reason to go out an try it just haven't heard why it won't work.

Frank 7a
 
Leaded gas a proxy

When pilots stop at certain airports, they sort-of apologize for not buying the pumped gas. Leaded aviation gas, maybe 20 years ago, became only-very-leaded-gas. 100LL or nothing. Airports are not neccessarily easy businesses to maintain, and owners hate to be put on the spot for another liability, so they're leery about supplying no lead for grounds equipment and other things. Home refueling prevails, but there are amateurs. People who very infrequently fly, can't drain 100LL into modern emissions cars, without causing damage. Stale gas is slated for the wild blue yonder. Not many passenger planes need boosted octane, and the physical lubrication baloney about leaded gas has balloned into an emperor's new clothes charade. Because 100LL is a metaphor for FAA inspection and bonus cash, even aero engine manufacturers have to advocate lead. Let's have safe gas without lead, more universal fuel supplies, and refueling at our favorite airports.
 
hecilopter said:
I bought my Superior engine because it was approved for 91 octane Mogas just in case. Then they promptly added Ethanol to all gas sold in Texas. Killed that one off before I ever even tried it!
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All mogas sold in Texas does not have ethanol. If you get away from the metropolitan areas, you can still find non-ethanol. Dallas, Tarrant and all surrounding counties have ethanol. Outside of that, regular gas can still be found. For how long? That's anybodies guess.
 
Supercharged and turbocharged engine can't get by with mogas at high altitudes or even low altitudes in some cases without manifold pressure restrictions. You would be making many radials and big turbo sixes like in PA31s, 400 series Cessnas etc. unable to fly. These engines don't have the benefit of modern chamber designs and require something better than 91 RON.

An unleaded avgas suitable for most existing engines is certainly possible to make today, I would think at similar cost to 100LL. It will happen sometime in the future, whenever environmental concerns make the politicians mandate it.

The ethanol thing really just involves changing out incompatible rubber/ plastic parts. Probably not too hard as long as you don't have bladders.
 
frankh said:
I highly doubt it. I think this is an OWT (old wives tale). This may have been true 20 years ago when soft valve seats were the order of the day but todays Lycomings (and clones) all have hard valve seats, thats why the clone suppliers are saying "yes" to premium unleaded.

I agree for some really ancient engines (I'd pity the radial engine owners) with the old soft valve seats it would be an issue...Nothing that can't be resolved with a simple AD right?...:)

Frank
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Can you explain this in a little greater detail for us non-technical types . . . The lead is supposed to lubricate the valve seats, but oil can't get there, however, gasoline can?

Thanks,
 
Certainly..:)

But remember this based on what I've read and some (hopefully common sense).

There is not an automotive engine in the world running leaded gas...So does it need lubrication?..Clearly it doesn't. ,

Basically you have a mixture of gasoline and air at an approximate 14:1 ratio that is on fire...Or WAS on fire....Now if so called lubrication was that important we'd have cars littered up and down the highways with burnt valves.

Having said that, years ago (like 20+) valve seats were made of soft cast iron (either cut directly into the cast iron cylinder head) or heat shrunk into an aluminium head.

When leaded gas first went away the wear rate on these valve seats went up significantly. The logic from way back when was that unleaded gas produced a somewhat higher exhaust gas temperature which the soft cast iron didn't like. As far as I remember the valves (steel) generally did OK but the seats got trashed.

Anyway, the auto manufacturers then found a more resistant alloy for the valve seats and this is what is found in all auto engines today...Namely a HARD valve seat.

I am reliably informed by the clone manufacturers that all Lycs have these hard valve seats.

There is a lot of old nonsense about the lead providing a protective coating on the valve seats...it might be providing a coating all right...like fouling the passageways in the head and sticking valves in the guides but there has been no documented evidence (as far as I'm aware) that this coating (if it even exists on valve seats) provides any protection whatsover.

This is just my humble opinion of course..:)

Frank 7a
 
frankh said:
Still have not heard an argument that makes sense as to why you can't have ethanol mixed with the gas....Not extolling this as a reason to go out an try it just haven't heard why it won't work.

Frank 7a
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Lots of non-metal things don't like ethanol - gaskets, o-rings, tank sealant, etc. It's easy to make these parts out of EtOH compatible material. How do you tell if you have a fuel system that is EtOH compatible? Easy - use MoGas with EtOH and wait for leaks. :eek:

Seriously, it's mostly a problem for older aircraft. When the automotive industry started gearing up for EtOH, suppliers started making components that were compatible. I suspect this has bled over to aviation components as well.

There's also the problem of water - EtOH is completely miscible with water and will help dissolve it in the gasoline. This can lead to bad things, including more aggressive corrosion with aluminum and other metals.

And then there's the small issue of EtOH having less heat content = worse mileage....
 
Timely article written last month by a 33yr fuel/oil veteran with Shell Oil:

Ben Visser

3/23/2007

As oil refineries stopproducing avgas, what'sthe future hold for us?

Adrian Lineberger, like many aircraft owners, is worried.

"I fly a turbocharged Cessna 206," he wrote recently in an email. "I was just wondering if you had any new thoughts on the fuel situation over the next five to 10 years?

"I think the industry is starting to see the writing on the wall as evidenced by production diesel engines on newer GA aircraft and the retrofit companies in Germany," he continued. "Do you still think avgas will be here for a while or is it time to shop for diesel conversions? Will unleaded or alcohol-based fuels be a viable option in turbocharged engines with appropriate conversions? I don't want to own an expensive aircraft that suddenly becomes obsolete with the next world disaster."

I understand Adrian's concern. At the present time there are 11 refineries in the U.S. that produce leaded avgas. It appears that Shell Oil soon will stop producing leaded avgas at one of its Louisiana refineries. This is a normal business decision based on the need for high octane unleaded components, normally used in avgas, for blending in auto fuels. Don't forget to factor in the high costs of operating a leading facility and keeping the leaded fuel totally separate from the rest of the products.

Other companies in the area have excess capacity, so I would not expect any negative impact on supply and cost in the short term.

But what about the long term?

The long term availability and cost of leaded avgas is still a great uncertainty. I was a little surprised last year that avgas prices did not go up more. Avgas is only 3/10 of 1% of the fuel market. As such, it is entirely at the mercy of the needs and demands of the auto fuel business. If the demand for high octane auto fuel goes up, the cost of avgas will go up significantly.

Now to my crystal ball for a look at the future: I see a cloud. It is called politics. Right now the war in Iraq is the main topic of political discussion. However, global warming and the environment are starting to get some play in the media. I am definitely in favor of protecting our environment and leaded avgas should not have any significant negative effect on global warming or the environment. But there is concern that once the government starts imposing new regulations, it will go after anything that even sounds bad.

So what changes will be made in the next five to 10 years? Probably very few. I think the diesel engine effort will grow significantly. This will be especially strong in the third world market where good quality leaded avgas is very difficult to find. Diesels also will see inroads in the commercial market. About 80% to 90% of the piston-powered aircraft flying today could be operated on a high octane unleaded fuel. However, the other 10% to 20% consume about 80% of the avgas used. Many of these high usage aircraft may be converted to diesel fuel for economic reasons.

If this happens, the need for leaded avgas will decline and eventually become unprofitable to produce.

But I do not see that happening in the next 10 years.

My best guess as to what will happen in the next 10 years in the aviation fuels business is:

? Leaded avgas will be generally available in the U.S., but at an increased cost;

? Electronic fuel injection and ignition controls will become more commonplace;

? Unleaded conventional avgas may become available that will meet the requirements of almost all of the nation's piston aircraft, with engine modifications needed for some;

? Alcohol will not be recommended for airplanes ? or their pilots.



Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985. You can contact him at [email protected].
 
Email from superior regarding engine lubricartion

The XP360 engine with standard 8.5:1 compression ratio is designed to run on
Avgas of 91 octane or higher with no additives such as alcohol or ethanol.
Lubrication is not an issue and many customers often use both 100LL and
Avgas.



Brent Henman

Customer Service Manager

Superior Air Parts

621 S. Royal Lane, Suite 100

Coppell, TX 75019-3805

I am pretty sure Mr. Henman meant "mogas" instead of "avgas". (comment added by Sam Buchanan, forum moderator)
 
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The original post claimed since Nascar went to unleaded fuel they are blowing engines at record numbers. That isnt true . We dont turn our aircraft engines 7800-9000 RPMs for 500 miles
 
tcrv7 said:
The original post claimed since Nascar went to unleaded fuel they are blowing engines at record numbers. That isnt true . We dont turn our aircraft engines 7800-9000 RPMs for 500 miles
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Still, it doesn't matter. Consider the twin-turbo 3.6l V8 from the Audi R8 Le Mans Prototype. It puts out 600+ Hp at 6200 RPM and runs on 100 octane (RON) unleaded gas and often races for 24 hours at a time. It has never had an engine failure in competition. They normally drive 3,000+ miles in 24 hours, going from slow second gear corners to flat out down the straight, thousands of upshifts and downshifts.

Unleaded gas does not have any inherent problems in terms of power or reliability.
 
the_other_dougreeves said:
Still, it doesn't matter. Consider the twin-turbo 3.6l V8 from the Audi R8 Le Mans Prototype. It puts out 600+ Hp at 6200 RPM and runs on 100 octane (RON) unleaded gas and often races for 24 hours at a time. It has never had an engine failure in competition. They normally drive 3,000+ miles in 24 hours, going from slow second gear corners to flat out down the straight, thousands of upshifts and downshifts.

Unleaded gas does not have any inherent problems in terms of power or reliability.
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All true, but very "last year" This year's winner, the R10 was a diesel (TDI.) I think this is a little view of the future. Problem is, for what the engine development cost Audi we could probably re-engine the entire RV fleet.

John Clark
RV8 N18U "Sunshine"
KSBA
 
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