Just curious, anyone heard any pros or cons on running 100LL AV GAS in a hemi? Its 100 octane low-lead fuel for piston engine airplanes. I have access to a bunch of it at work (I'm allowed to use it, i'm not stealing it) and they said I could fill up on it. I have also heard that mixing it 50/50 with pump 87 octane would work too. I am hesitant, I don't want to damage the engine or valves or anything at all.

 

If im not mistaken, running that stuff straight will end up burning holes in the tops of your pistons. That stuff runs pretty hot. Mixing it should be ok like maybe 60 gas 40 AV

 

It's simply higher octane gas that hasn't had road taxes added to it. The lead will make sure any catalytic converter(s) you have left will be solid bricks pretty quickly and your o2 sensors will be fouled.

 

EXACTLY what he said. You stated yourself that the AVGAS is LOW lead, not NO lead. Tetraethyl lead in gasoline is completely incompatible with catalytic converters and O2 sensors.

That being said, you're really not going to see any increase, even without the cats & O2 sensors fouling. Higher octane in gas doesn't MAKE more power, it simply allows more power to be made by eliminating knocking or pre-ignition.

semigod - AVGAS or any other high octane gasoline based fuel does not burn 'hotter', it burns slower. You'll never burn holes in pistons by using a higher octane fuel.

 

Used to burn 100 LL in my Cessna. Had to pick the little lead ***** out of the plugs fairly often. Pretty sure your cats would be toast in no time.

Rick

 

It will also clog the injectors. It does smell good, but not compatable with EFI engines. My brother in-law used to run it in his race car.