Question about Saw Fuel

vsteel · Jul 25, 2003

While the smaller race fuel companies might use it as a base stock, just burning it pure is not good for motors not designed for it. Its a dry fuel, designed to be evaprative in very cold weather with slower running engines. For the most part its a slower burning fuel, thats why people will say wow, I was making so much power that my exhaust was red, when its really the unburnt fuel.

Just burn the lowest octane gas you can that won't give you problems. Or if you are hell bent on burning av gas mix it with gasoline for cars to get some of the lubricating additives in it.

bwalker · Jul 25, 2003

The dry fuel, slow burning old wives tails about avgas are non sense. It actually has a high 10% boiling point to ward off vaporlock so it isnt designed to work at low temperatures like you say. It also doesnt burn any slower than pump fuel. octane and falme speed are not interelated. The highest octane pro stock drags fuel have the highest flame speeds. The red headers(4 cycles) you mention is the result of a stuck choke or a over rich mixtures. The lubricity issue doesnt exist as pump gas and av gas have no lubrication ability in and of themselves. Some people call av gas "dry" because it has excellant solvency charachteristics.

Crofter · Jul 26, 2003

Carburetor icing is a big concern with piston engine aircraft and I believe Av gas is formulated with this in mind. (Evaporative cooling effect) Vapour lock resistance could be a tradeoff but not likely as big a concern to aircraft application. Good or bad for a saw???
Frank

bwalker · Jul 26, 2003

Good or bad for a saw???

It is very consitant from batch to batch, doesnt contain alchols, and is mandated by law to be of good quality so I would say its pretty good.

HUSKYMAN · Jul 26, 2003

The only bad thing about avgas is the extreme amount of lead in it. Over time it could cause deposits.

No real advantage to running it unless you have a shaved jug for a compression increase