Environmental News

Reading “tales of old Florida “
Interesting how they weren’t sure if a sponge was a plant or animal in the late 1800’s.
Even now, reading about them, definition is not simple for a simple organism

 

Ah the good old days of living by roads and freeways populated by leaded gas drivers. But absence of quantitative data in the report makes me skeptical of some of the claims.

Sad to say, today’s piston engines have more in common with 1930s tractor engines. They still use monstrous carburetors and magnetos. Air cooled instead of liquid, they run inefficient rich. Worse, not even a two speed propeller gear to optimize the power plant.

Bob Wilson

 

What an interesting article. It appears, nearly all the way through, to be only about neurotoxicity from the lead added to avgas.

Only in the fourth paragraph from the end does it mention, understatedly, "a manganese compound called MMT, another neurotoxin that EPA unsuccessfully tried to ban in fuels during the 1990s only to be stopped when Afton, also the sole supplier of MMT, sued."

Haven't a lot of them got variable-pitch blades?

 

Um, lead free, ethanol free, 100 octane racing fuel has been around for years. Why can't it work?

VP 100 Octane Fuel | MOTORSPORT 100 (MS100) | VP Racing Fuels
https://torcoracefuel.net/products/torco-race-fuel-100-unleaded

 

Sad to say, no. The variable-pitch propellers are a mechanical nightmare with obscene stress. In contrast, a simple, two-speed, gear reduction unit can solve multiple problems:

• Optimize climb or cruise performance - in practical effect there are only two setting needed. The climb and takeoff gearing allows the engine to operate at a peak power setting at low speed. The cruise setting allows to propeller and engine to operate at maximum efficiency for range at cruise speed.
• Gears are well known - dealing only with torque, a simple planetary gear and brake band can implement the two gear ratios easily with minimum parts.
• Avoids dealing with propeller hub stress - keeping the blades from flying off while changing the pitch is a hard problem.

Bob Wilson

 

I had somewhere stumbled on an article—maybe it was this one:

https://www.centennialofflight.net/essay/Evolution_of_Technology/props/Tech14.htm

—saying "Today, variable-pitch propellers are common to virtually all propeller aircraft."

But that article itself isn't dated, so I don't know when "today" was. (It cites a 1990 source, so I guess not earlier than that.)

And I don't fly, myself, so if Google told me all propeller aircraft had turbo encabulators, I wouldn't know any better.

 

There was a link to a spec sheet on both. Didn't post them cause they didn't lead back to the main page.
https://cdn.shopify.com/s/files/1/0058/8110/2447/files/Technical-data-sheet-100.pdf

The $11 was for local pick up, and likely from a pump. From what I've seen on the puregas site, speed shops sell 100 octane by the 5 gallon jug and 55 gallon drum in the $8 to $10 a gallon range. That was pre-pandemic though. Avgas 100LL ranges at $6.42 to $7.12 gallon.

Came across this, Avgas pricing - AOPA, while looking up the avgas price. Turns out those racing fuels are too low in octane; they are 100 AKI, avgas is 105 AKI. I'm guessing the 100 rating is MON. That test fits carbureted engines. Most of the world uses RON on the pump because it better represents the fuel's behavior with injected engines. VP Racing is part of a team working on 100UL.

That posting discusses the market forces and potential price of 100UL.
"Bottom line. 100UL avgas is coming. Pricing shouldn’t be dramatically different than today. But some different market price factors will affect 100UL than affect 100LL today. The relative ease of blending unleaded avgas compared to leaded avgas may lead to more market competition, and we will all benefit from that."

 

Dad spent roughly a decade flying with a pilot friend, who needed a flying partner after his spouse didn't want to go anymore. Dad never got far enough to get his own license.

His version of why much of GA is stuck in the past, was fear of liability over new tech, when the old tech is proven and well understood.

 

Fuel blending isn't exactly a new technology though. The required octane can be reached with using compounds already well known. Getting lead out of avgas should not have taken decades after it was gone from mogas in the US.

 

It isn't just a fuel blending issue. The engines must be changed to run unleaded, as the lead turned out to be a lubricant for valves. Other vehicles made the switch, I'm not sure what is holding up the aviation industry there, other than the possible prospect of scrapping the old-era engines.

 

I’m leaning toward electric with possibly a small range extender. Clean sheet, transplant an auxiliary power plant from a jet or a hobby jet driving a generator. This solves the problem of getting a charge at airstrips lacking a charger.

Bob Wilson

 

But it didn't take decades to figure out the valve issue with unleaded gas. Considering the more in depth maintenance aircraft engines see than cars, refitting new valves shouldn't be a big issue. Most of the blends being considered now aren't using new compounds. Maybe vapor emissions is a concern for the EPA.

It is more likely the few TEL producers and 100LL blenders not wanting to give up a cornered market income stream. Leaded gas for landcraft was officially phased out in 1996 for the US, and 2021 globally. How many producers are left?

 

can they beat toyota to market?

 

Everyone is beating Toyota to the EV market. But Toyota is not alone.

I am reminded that pre-PIP, there was a cottage industry converting Prius to plug-ins.

Bob Wilson