Can i run 100% AVGAS 100LL?

[Mally69]

I may be misinterpreting the OP, but I think he's saying his car runs fine on his 95 (probably the same as our 91, just rated differently) but he's worried about the valves and seats, from unleaded fuel.
We basically told him that a gallon or two 100LL in a tank is plenty to save his valves, IF he can get it.

Well its def a better fuel or they wouldnt use it in an airplane. Secondly, i run it full concentration i dont mix anything because when u mix it then tune ur engine its tuned for that tank of fuel. Next fill up its going to change unless u have the EXACT ratio again and that's hard to do or not going to happen. I never understood why these guys mix it because they damn near never get the same exact ratio. Also my dist is locked out so i dont have an ignition curve, so with that being said I've i put the fuel in i turn the distributer to where it runs the smoothest and bolt it down and leave it. U manipulate the burn by advancing or retarding the timing. To be honest, i leave the timing light on the shelf because once i advance the distributer to where it runs the smoothest, last time i checked it with a light it was 40° advance or slightly more in ( my specific engine). I run about 10.5 - 10.8 static compression with alum heads. That fuel burns slower an colder so that's why it takes more advance. Every engine will be different. But mixing it. I just don't understand because you'll never get that ratio perfect next fill up unless u like retuning with each tank.

 

[biomedtechguy]

I personally run around 33% avgas, because my combo is on the ragged edge of running on pump (it will, if I take a couple degrees out), and I CAN get it.

That sounds like an ideal application for mixing in AVGas.
NOTE: Part of the reason why I am EXTATIC about the Progression Ignition system is the "If I have a high performance engine build, naturally aspirated, and I run a higher than 93 octane petroleum based fuel on race day, (like 100 octane AVGas as an example) can I get a significant increase in power?"
I know that is likely a "try it and see" answer, unless you have a fairly high compression ratio and are having to compensate with less advance at WOT than the degree that provides the highest output.
With the Progression timing tables, you can have a number of advance curves and total advance levels to try and see with the press of a couple of buttons.

 

[66Satellite47]

Gas has been an issue as long as I can recall. In the mid '70s for my drag car, I mixed AV 100 gas 50/50 with my 12.4 CR motor. Ran great. Even when they went to LL 100, worked great. I even tried the purple military 140 (helicopter) stuff. AV gas can help.

 

[RemCharger]

Well its def a better fuel or they wouldnt use it in an airplane.

Makes sense.
Like putting A1 steak sauce on a chocolate cake.