AV gas for the generator

[wopachop]

A Facebook friend just posted a spot hes getting AV gas at. Runs it in his generator. Any of you old school guys have advice on slight tuning changes? Lean out the altitude screw maybe? Different plug?

I'm mostly just curious. Enjoy topics like this. Next camping trip maybe I will finally try AV gas. I've heard about people using it for offroad toys.

[MEXICOWANDERER]

Years ago the blend of avgas at dispatch used a centrifugal spin filter special tank trucks for both 87 and 110 L/L. Both grades were the same fuel except the leaded 110 contained 10% more alkylate and 1.3 grams of tetra ethyl lead per gallon. Purple 110/145 octane was highly restricted because it contained 50% alkylate and 5.2 grams of TEL. It cost 20x more than 88 octane and did absolutely zero for a snowblower and my Sunbeam Tiger. But on the other hand 12.5 to 1 pistons. Giant valves and a full race cam worked magic on a propane 350 engine in a pickup truck. Butane cost .45 a gallon down here then.

[wopachop]

Chum lee wrote:
I'm a private pilot. Right now, the average price for 100 octane low lead AVGAS is $5.17/gal in the SW USA. IMO, this fuel will work fine in your generator, but, . . . why would you consider using it when 87 octane unleaded fuel (the correct fuel for your generator) is readily available in SO CAL for under $3.00 a gallon?

Chum lee

I dont put 87 in anything. AV gas is $3.50 and 87octane is 3.29. My buddy who posted the AV gas price was excited i think because it was a good deal. We are desert people and its been a good 10 years since i heard talk of guys running AV gas in their sandrails or dirt bikes. When he posted about using it for the generator i thought it could be something interesting to look into.

For me its hard to keep fresh gas in my genny during the summer. I literally add 1 gallon every 2 or 3 months. Just so i can start and run the genny for 45-60 mins.

[wopachop]

prichardson wrote:
Ditto. Running any engine on a higher octane fuel than what the manufacturer recommends is a waste of money.

Not always. Ive been putting 110 octane fuel into small engines for 25 years. People often overlook how excessive engine load can cause knocking as well. Its not strictly about compression ratio. Swear to you i currently have 8 month old 110 octane inside a little 1989 TW200 motorcycle. I ride this bike every single day up and down the same hill where i live. While it does not need 110 octane, i promise you there is a performance gain. The bike makes 15 HP i hold the dang thing wide open and ride it like a maniac. It runs stronger on race gas. Its even mixed to 40:1. Only running it because i ran out of regular 91 and need to use up the old gas.

Another thing people dont consider is that yes the manufacture recommends 87 octane. Trailer sits for 6 months. What octane do you think that gas has degraded to? I always put 91 into my trailer for this reason.

Lwiddis wrote:
Why not just follow the engine manufacturer’s recommendations?

Because with very basic modifications you can increase efficiency. I have never owned a vehicle and left it completely stock. For example the big ole Donandson air filter on my 7.3L. It filters better and flows better. Engine manufacture would most likely recommend i buy a motorcraft filter im guessing. I like OEM for some things. Aftermarket for others. The manufactures engine tune is junk. You can increase power and fuel economy if you dont follow the manufactures tune.

[Chum_lee]

I'm a private pilot. Right now, the average price for 100 octane low lead AVGAS is $5.17/gal in the SW USA. IMO, this fuel will work fine in your generator, but, . . . why would you consider using it when 87 octane unleaded fuel (the correct fuel for your generator) is readily available in SO CAL for under $3.00 a gallon?

Chum lee

[EV2]

hypoxia wrote:
The only advantage I see is if you plan to leave the generator sit unused for years.

On point...

[EV2]

Without recommendation, the best quality of a gas can be proven to be a higher level of refinement. Compare two clear jars with a pint of auto fuel vs a pint of 100LL after evaporation. The LL jar will be almost clear and the auto fuel will show considerable varnish.

[hypoxia]

KD4UPL wrote:
What's the point of paying for / running AV gas?
If you want ethanol free then just buy ethanol free. It's readily available just about anywhere.

Ethanol free is nearly impossible to find in some parts of the country. Marina boat fuel and racing fuel is about it.

Airplane spark plugs accumulate balls of lead from 100LL avgas. The only advantage I see is if you plan to leave the generator sit unused for years.

[Lwiddis]

Why not just follow the engine manufacturer’s recommendations?

[prichardson]

Ditto. Running any engine on a higher octane fuel than what the manufacturer recommends is a waste of money.

[KD4UPL]

What's the point of paying for / running AV gas?
If you want ethanol free then just buy ethanol free. It's readily available just about anywhere. I only put ethanol free in my boat and my small engines. Pure-gas.org lists over 15,000 stations selling ethanol free in the U.S. and Canada.

[richclover]

wopachop wrote:
A Facebook friend just posted a spot hes getting AV gas at. Runs it in his generator. Any of you old school guys have advice on slight tuning changes? Lean out the altitude screw maybe? Different plug?

I'm mostly just curious. Enjoy topics like this. Next camping trip maybe I will finally try AV gas. I've heard about people using it for offroad toys.

Unless it’s an old generator I wouldn’t run 100LL in it. “Low Lead” is still leaded. All my small engines are designed to run on unleaded gas. I found a station in town that sells clear gas (ethanol free). That’s what I use in my small engines now. It’s cheaper than avgas at my local air patch 😉

[wa8yxm]

Should not require any adjustment on older generators.

The issue is the alcohol in automotive gas.. And it's not so much rich/lean (Gas-ahol is a bit "leaner" so you need to enrichen a bit) but the way gas breaks down over time.. Gas-ahol breaks down fairly fast relative to pure gasoline.

There are some other issues. too much booze in the tank and there is engine damage as well. UNLESS the engine is designed to run on boozy gas that is.