• gramie@lemmy.ca
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    14 hours ago

    Just today I learned that the fuel Cessnas use has lead in it, because the engines were developed when lead was in all gasoline and they have not found it worthwhile to certify all of those tens or hundreds of thousands of planes with new engines.

    In fact, I was at a fly-in today and there were several Cessnas that were 60 and 70 years old. no unleaded fuel, and no added ethanol, either.

    • Captain Aggravated@sh.itjust.works
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      13 hours ago

      So in the specific case of Cessnas, the first Cessna 172 to require leaded fuel was built in 1977. That was the year they switched from a 6 cylinder Continental O-300 engine to that goddamn 4 cylinder Lycoming O-320 H2AD engine. Bigger displacement, two fewer cylinders, more compression, required leaded fuel.

      I gave flight instruction in a new built light sport aircraft equipped with a Rotax 912 engine. Instead of Lycoming and Continental’s 1930’s era tech, BRP-Rotax’s aircraft engines are basically 1980’s motorcycle engines. Water cooled, Nikasil cylinder linings, electronic ignition, constant velocity carburetors or EFI, gear reduction, and they run absolutely fantastic on regular automotive gasoline. No lead.

      • gramie@lemmy.ca
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        11 hours ago

        Thanks for the additional information. Everything newer seems to be Rotax now. Except there was one guy who had a Corvette engine in his Cessna. Other pilots were talking about how it has so much torque his rudder isn’t big enough to compensate.

        Hopefully in 5 or 10 years, everything will be electric!

        • Captain Aggravated@sh.itjust.works
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          10 hours ago

          I mean Rotax is kicking some ass, they’ve got a 160 horsepower engine now, weirdly enough out of the same displacement as the 912S. Imagine if they made a 6 cylinder variant, damn thing could make 300 horsepower easy.

          I cannot think of a reason to use a Corvette engine in an airplane other than “fuck it.”

    • FordBeeblebrox@lemmy.world
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      13 hours ago

      It’s an issue with machining tolerances of block/cylinder/piston/piston rings, older planes need lead to reduce the piston knock or it could damage itself. Modern engines have much tighter tolerances, but it would mean essentially rebuilding or replacing the whole engine on every piston engine plane. It would be great if we could phase out leaded Avgas but it won’t be going anywhere anytime soon

      • Captain Aggravated@sh.itjust.works
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        13 hours ago

        False! The industry is phasing out leaded gasoline in 2030. California signed a ban on leaded gasoline after 2031 into law. There are some aircraft out there that I wonder what’s going to happen, but a lot of the GA fleet is going to be well supported.

        In addition to that, there’s an expansion of the light sport rule in the works which should allow most of general aviation to advance past the 1970’s.

        • FordBeeblebrox@lemmy.world
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          12 hours ago

          I knew we were moving away from it but didn’t know Cali set a date, thanks for the info. I imagine there will be a big market for grease monkeys to put all this in place

          • Captain Aggravated@sh.itjust.works
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            11 hours ago

            There’s gonna be a lot of pencil whipping by A&Ps I think. If I understand correctly, the way they’re gonna deal with it is roll out a high octane lead-free fuel that just works, so most of the mechanic’s job is going to be putting new stickers next to gas caps and signing logbooks.