Uncle toys .. check your P.M.

This is somewhat along the same subject. I am interested in knowing the "life" of gas these days. I have read in a previous thread that Av gas has a longer octane life than what you get from the normal gas stations, where I get mine (normally 87 octane). I don't use the hi-po fuel but am wondering how long I can get away with pump gas in my boat without having to worry about the octane level getting weak. I use the Sta-bil additive most all the time.

You must be careful with AV Gas, for a few reasons.

If you have ever spilt any you will notice that it evaporates rather quickly----reg fuel does not do this (as quickly). AV is not rated the same way as street fuel, its research octane. It does not factor in motor octane---the one that counts.
Consider that AV fuel was designed for a low rpm (1000 foot per minute piston speed), air cooled engine.
AV fuel is also know to run dry, their is also a chemical reason for this, having a fowled spark flug in the air would not be your favorite thing to happen, so AV has a chemical that disperses oil (including Marvel Mystery). All oil (even a lot of it)will be rendered ineffective by this chemical. It will be hard on rings and valve guides.

In short if your motor needs race gas, buy race gas.

RT

I don't know...my engine builder recommends it, I know alot of people that use it without problems, and when I was running outboards all the Merc techs recommended it. just my .02

Newer engines have hardened seats in the heads and will not have a problem with Av gas.

I used to use AV gas in my race car, it is a little dry, but as long as the motor is in good shape this is great stuff....

Hey Gary,


What was that about blowing-up a DRIVE? Av Gas umm.




That B-Max must be looking good.

Aviation fuel is around 108 Octane, they call it 100LL because that is considered a bare min. It does burn very dry so a lubricant won't hurt. My engine builder recommends it (he builds Pro stock NHRA drag motors), although not for this application, and I personally know individuals with 1000 SC Mercs that burn it all the time. Never heard of any problems. 100LL smells just like racing fuel.

I have been runing av gas for over five years in my boats.....I have never had a problem. Hell I run it in my aqua scooter and all the quads,the best thing about it it does not go bad after a month or two.