Avgas Update

[WKPoor]

Well its been about 3 months now that I've been running Avgas in not just tractors but everything at my house that doesn't say "EFI" on it. Here is my conclusion: Pump gas is junk-repeat-JUNK, barely anygood for anything but washing parts. Pour it out in a pan alongside another pan with Avgas and the pump gas might lay there for almost a day. The Avgas evaporates in minutes. Unless your fuel delivery system sprays it under pressure and your ignition system is hot hot that stuff just doesn't burn right. I got to thinking about all the problems I've had with other things like the my Boat fouling plugs last summer at Cumberland and how the pressure washer is hard to start after it is run awhile. With Avags the washer starts right up easily. The chainsaw starts on the first pull now everytime. Basically, yes there will still be issues where indeed overfueling will be why somethings are fouling, but I believe the problem is worse because the fuel we now buy at the pump is JUNK. It smells bad because it is bad. Can't wait to see how the boat performs this summer with good GAS!!

[John *.?-!.* cub owner]

. Pour it out in a pan alongside another pan with Avgas and the pump gas might lay there for almost a day. The Avgas evaporates in minutes.

Wonder how much you will lose to evaporation in a a tank that has open vents like an antique tractor rather than a closeed system.

[WKPoor]

Must not be too much of a factor as aircraft wing tanks vent the same oldfashioned way. Its a fact though, spill a little on the concrete and it goes away like laquer thinner. Spill some pump gas and its there for hours. I'm a thinkin cars don't atomize quite as well as fuel injection and thats why these fouling issues are becoming more prevelant. Couple that with the fact that carbs can't regulate fuel/air ratios as well and the problem is compounded. Add in a situation where the carbs a little rich to begin with and the blaim falls right square in the carbs lab. Quarantee you take that same situation only add Avgas to the tank and that rich condition will go away.

[Charles (49) Mo]

Being an ex-AC owner of a 182,1960 model, I agree with some of your points. However, many older AC had a STD available for auto gas useage. Then 80 octane avgas was being phased out and 100LL avgas was the norm. Our Cub gets worked hard for 6 or 7 hours steady, every couple of weeks. And I wonder if light loads and not being brought up to operating temperature for hours might be more of a problem?

[WKPoor]

Charles, You are correct that light loads and low operating temps is another angle on the protractor not helping the problem. As for STC'd aircraft, that has always been controversial. 10yrs ago I would say it might have been ok, but not now, no way. Knowing what I now know about fuels, I wouldn't want to be off the ground with pump gas in my tanks. How would you know whats really in there?

[Donny M]

Diesel...Problem sloved

[Jim Hudson]

All my junk runs fine on Rot Gut gas!!

[WKPoor]

Diesel...Problem sloved

Donny, You don't know how funny that statement was. I here that at least a couple of times a week. Same person tells me to sell all my antiquers and get one new compact and be done with it. I'm just wondering were the fun in that would be.

All my junk runs fine on Rot Gut gas!!

Jim, You got any Gravely machines around there? I'm talkin L Models walk-behind. You know the kind-that like to pull your arm out of its socket when they kick the wrong way on a pull start. Thats that good ole rot gut gas for ya!

[Ron L]

Bill. I know what your talking about with those Model "L" gravelys. I only wrap the strap around 1 1/2 - 2 times now .....

[Harold R]

I have to agree with Jim H. All my stuff runs good on 87 octane pump gas. With Avgas north of 3 bucks a gallon, my tractor will continue on 87 octane pump gas. Avgas is a throw back to WWII when high performance aircraft needed a common fuel that would run high compression engines from sea level to 30+ thousand feet, and from 120 degrees(F) to -50(F). Today's application is still important, as the piston driven a/c still have and need high compression, operate with changing fuel/air mixtures, and wide temperature range.
With that said, running 100LL probably will have no short term effect on your equipment. Unless I had something, (like my old street-rod), with better than 10.5 to 1 compression ratio, I'd just buy some lead additive or octane booster. Besides, I wouldn't want to get my cub hooked on something I can't afford.

Oh, by the way, If you running 100LL avgas in your automobile, your local DOT rep will appreciate you using the "road-taxed" version.

[Carm]

No doubt Avgas is some fine stuff. There is not really any problem since the lead content is so low. I friend uses it as winterization fuel for his boat, the last fill up of the year is avgas and then he tops it off for the winter. We used it in an old Dodge pickup that ran like crap and it helped. I wonder though, if the quality of the Avgas helps to mask the problems wit equipment that does not run right on regular pump "rot gut". I love the stuff. Oh, and Donny's suggestion to go Diesel....I have Jet fuel for that!

[Harold R]

Donny, wonder what a load of "Jet A" would do in your truck.
May get home a lot quicker.

[S.H.A.F.T.]

What is the octane rating of the aviation fuel? It's over 100 isn't it? Do you know how much tetra-ethyl is in it? I wonder if it has the same lead content as the old leaded gas?

S.H.A.F.T.

[Harold R]

I think avgas has been "Nader-ized" as well.

[Lurker Carl]

Jim, You got any Gravely machines around there? I'm talkin L Models walk-behind. You know the kind-that like to pull your arm out of its socket when they kick the wrong way on a pull start. Thats that good ole rot gut gas for ya!

If your "L" model Gravely is kicking back, the problem is not fuel. The timing is too far advanced or your magneto needs some mechanical attention.