One compound that refiners added to gasoline, both automotive and aviation, was tetra-ethyl lead. This improved the anti-knock or detonation properties for the high octane fuels such as 100, 115, 130, etc. aviation fuels. The EPA banned the use of leaded fuels for automotive applications and is pushing hard for the same ban on 100 LL. Problems with leaded fuels are sticking exhaust valves and rings, burned exhaust valves, corroded exhaust pipes and mufflers, fouled spark plugs and plaque in carburetors and fuel injectors. Actually the EPA was not concerned so much about engines and such, but what the free lead in the exhaust emissions was doing to people. Problems cited were still borne and deformed babies, and retarded kids from lead poisoning. Adults are not immune from such nerve damage either.
My understanding is there were no production engines designed to run on leaded fuel per se. Rather the designs were for a specific octane fuel. Compression ratio is the design parameter. The cheap way to get the high octane fuel to perform correctly was to add the tetra-ethyl lead. Refiners did figure out how to make high octane fuels work without the lead, such as the automotive gasoline we use and pay dearly for today. Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA sidney.w...@titan.com -----Original Message----- From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf Of Allen Wiesner Sent: Thursday, August 18, 2005 3:20 PM To: KRnet Subject: KR> Re: Auto Fuel/Avgas IIRC there "used" to be an lead? additive that could be added to gas for engines that were designed to run on leaded fuel; does it still exist? and if so, what is the name/maker? _______________________________________
