Anyone run AV gas? AV gas at the small airport right near the lake is about the same price as marina gas....

Dean,
Avgas is less dense than most racing gasolines. Instead of weighing about 6.l to 6.3 pounds per gallon like racing gasoline, it weighs 5.8 to 5.9 pounds per gallon. This lowers the specific gravity so it will require a change in air-fuel ratio calibration for the engine to perform safely. The other major difference is octane quality. Avgas is short on octane compared to most racing gasolines. The ?Aviation" antiknock rating system is different than the MON rating. 100-oct. on the aviation scale, equals 98.8 MON. Many performance engines have more spark advance at low rpm and/or during lean, part-throttle operation than AvGas can handle. The result is detonation. The notion that avgas is superior or even comparable, particularly in marine applications, is urban myth.
Bob

thanks for the cliff notes version of the whole story....... that is what I like about this place, quick and down to the basics info............

thanks again, I will just keep pumping that fuel from the marina I guess...

If your choice is pump gas or 100ll av gas I would go with the 100ll. I had some 1050's that were set up a little on the lean side for 93, I decided to run the av gas and never had a problem and I ran this boat hard.
I spoke with Mike at sterling and he said the av gas was much superior to pump fuel and that the valves would really like the lead content. He did say that race fuel would be his first choice though. Just my experience..

ditto. However, if comparing 100ll to 100+ (such as camII, etc) octane, lead or unleaded, non alcohol racing fuel, go the racing fuel. I don't know where you live, but look around. Where I live (Iowa) 110 unleaded non alcohol racing fuel (shell Cam II, according to their distributor) is available at select Kum and Go (quicke marts) for LESS $, currently $4.30/gallon, than 100LL local airport, $4.59/gallon.

i ran thousands and thousands of gallons of 100 ll thru my 10:1 motors and it was wonderful.... and cheap at the time. the motor has to be jetted for it as noted above but in anything less than 10 :1 normally aspirated, i would run it all day ESPECIALLY for the quality control aspects of it vs ANY marina...

im paying 425/gal for fuel here that comes off a south amercan freighter in barrels.... ide kill my mother for some good av gas...

AvGas:

AvGas is higher octane, which can be a benifit for some marine engines. The BIGGEST problem or downside to the AvGas is that is engineered to run at an engine RPM of 3500 to 3800. Not optimal for your boat.

Now if you have an engine that really needs high octane fuel, buy the right fuel and be done or change the calibration on your engine. If your engine is borderline then mixing AvGas with a good 100ll or 94 pump gas can be a good choice However you will need to change your tuneup in order to do this. So this will require either running the engine on a dyno or installing O2 sensors in your exhaust.

I Have Been Looking For A Thread All Morning That Had A Link To A Site That Would Calculate If You Had 30 Gallons Of 89 Octane And Wanted 96 Octane It Would Tell You How Much Race Or Av Fuel You Would Need To Get Add To Get To 96octane

Could Someone Please Find The Link.
Thanks Aptrick

BY U BOY
http://www.motorsportsracingfuels.co...alculator.html

THANKS THAT IS EXACTLY WHAT I WAS LOOKING FOR