How long will 100LL last?

[RDRickster]

http://www.aopa.org/whatsnew/newsitems/2004/040811avgas.html

There is only one TEL (tetra-ethyl lead) supplier left. Avgas is a high-cost, low-volume product for refiners, representing less than 0.2 percent of their total output. The few refineries still producing aviation gasoline only devote a few days a year to making batches of avgas. They have to shut down and purge their systems after refining avgas because of the lead. Undoubtedly, some refiners will make a business decision to stop making avgas (as Kern Oil did), and ultimately the government will ban all leaded fuels.Comments?

[George Semel]

There has been this talk for as long as I have been flying, and I started in 1974. In that time I have seen 80 100 115 oct grades of Aviation Fuels. Its now pretty much 100 LL and STC's for Auto Fuel. Avgas has always be sort of an orphan since 1973 embargo. There are a lot of piston Aircraft still being flown in the world, and most of them are airplanes. Once a diesel option comes along. There are some weight issues with that, once solved you will see aircraft re-engine and then it will be a Jet-
A world. The thing is that its not going to be in my life time your yours.

[Chimbu chuckles]

A company in the US is designing a proper electronic ignition timing device that will be able to be fitted to most of the higher powered piston engines...IO520/550/TIO540 etc...you get the picture.

When that comes on the market it will mean that engines that currently require TEL to control detonation while still producing sufficient power will be able to swap to unleaded super 'mogas'.

TEL is VERY bad stuff and the limitations on 100LL manufacture and transport are as you suggest...somewhat stupifying...but to just stop manufacturing it until an option exists and grounding 10 of thousands of piper, cessnas, beechcrafts, and the various piston flingwings is not worth considering.

Chuck.

[headsethair]

I read a CAA paper on this recently. If 100LL goes it really "only" affects turbo-charged engines. Normal forecourt fuel for non-turbo aviation engines is fine = "premium unleaded". (But illegal in the UK)

[RDRickster]

This may have been a long time coming, but the time for 100LL is winding down (another 10 years). As of now, there are NO producers of 80 Octane AVGAS and there is only ONE producer of 100LL. The fix will be in the form of a fuel additive, because I doubt that engine modifications will work given the diversity of the piston fleet.

[Lu Zuckerman]

The US Army, which at that time was flying a lot of Bell 47s, and Hillers as well as L-23s and L-19s used an additive made by Shell. It was Tri Cressel Phosphate (possible misspelling) and it was abbreviated TCP. The Army mechanics called it TomCat Piss.


The TCP scavenged the TEL during the combustion process keeping it from plating out on the plugs thus lengthening the time between plug changes.

During my military stint we were flying a Bell 47 and a Sikorsky S-51. The Bell was designed to run on 80 octane (no lead) and the Sikorsky on 91 octane, which had lead in it. On board ship we could carry only one type of fuel and that was 91 octane. Using 91 octane in the Bell resulted in plug changes about every 20 hours, which kept me quite busy.

:E :E

[B47]

Lu,

Were you flying turbo-charged 3B-1s?

As someone who expects to keep his classic Sioux running for longer than the next ten years, what is the reason for turbo-charged engines being fussier over the alternatives to 100LL?

[Lu Zuckerman]

To: B47

When I was working on helicopters the only thing flying for the USA that had turbo super chargers were B-17s and P-38s. There may have been more. The biggest engine in helicopters at that time were 985s,1340s,1300s.

:E :E

[Steve76]

B47,

The benefits of 100 leaded are various but predominantly two fold.
100 octane for anti-detonation qualities and leaded for valve lubrication.
Your 47 will need to have 100 octane for the anti-knock characteristics. With the pressurisation of the cylinders by the turbo the increased pressure can preignite the fuel/air mixture before the spark is introduced. The 100 provide more power in the increased pressure cylinder as well.
As for the rest of the non-boosted machines, I agree that a better ignition system with more accurate metering of fuel, ignition and air will allow a comfortable transition to the cheaper "MOGAS".

My old turbo Cordia loved the Avgas and there are many pilots still out there who daily save the fuel drains for the free miles.....
My bike loves the lead too. :ok:

[headsethair]

CAA diiscussion docs here - pdf:

http://www.caa.co.uk/docs/393/srg_acp_00013-01-300103.pdf

http://www.caa.co.uk/srg/general_aviation/default.asp?page=630

[Spunk]

Maybe I've got a language problem but there are already certified diesel engines out there...
Diesel (http://www.centurion-engines.com/)

just to name one...

[Avtrician]

I would not recomend Lead Replacement Petrol (LRP) for use in any engine, it not only cloggs carby jets and valves, but the bowsers as well. My XD falcon hated the stuff, ran like a two legged dog with a handicap. Premium was ok, normal unleaded no good.

definitely no good for your MX5:yuk:

[Head Turner]

Getting rid of Avgas and avgas fuelld engines should be a priority. The piston engine manufacturers have had their day and the sooner the diesel is the norm the better. Until then there are going to be many refuelling errors.

The diesel is environmentally friendlier and maintenance ought to be less.