<<You cannot find a single reference in the SAE literature that attributes any premature valve failure to the presence of oxygen in the exhaust stream >>

That's because there IS no oxygen in the exhaust stream.

It is a misconception that you mix fuel with air, burn it, and get exhaust products which are water + carbon dioxide + excess unreacted ingredients.  If you're running lean of peak, you don't have any oxygen molecules in the exhaust. If you're running rich of peak, you don't have any unburned gasoline in the exhaust.

What you *really* have is an exhaust product mixture containing largely carbon dioxide and water vapor, but also partially reacted ingredients and partially decomposed (the precise term is "dissociated") products.  Where you sit on this spectrum depends on many things, but the fuel-air ratio is probably the biggest factor.  Think of carbon monoxide and carbon dioxide in the exhaust -- if you had more oxygen to start with you'd have more dioxide and less monoxide in the exhaust, but you'd always have some of both.

Well, enough non-Lancair-related rambling.  What I *really* want to know is why I can't run my IO-360 powered Lancair with autogas, but I can run my O-200 powered Cessna and the buddy's O-360 powered Skyhawk with autogas....

- Rob Wolf