AVGAS 100LL Replacement

[bushpilot357]

Hi friends:

I own a PA18-150 and have just now installed a new factory overhauled
engine. I will get a certificate which allows me to operate the
aircraft on Auto gas. I intend to use 95 Octan rated Super as we use
it in Katanas (AVGAS is extremly pricy here in Austria). For the
break in period I will stay on AVGAS only as the lead content is
needed for lubrication. After break in I use a tank of AVGAS every 25
hours or so to have some lead in the engine.
I am limited to 10.000 ft due to the vapor problem. So that's what I
know. Is anybody out there who can give me some additional
information or has used Auto gas in his engine.

Regards,

Peter

[Rick Sanson]

I had my O-32A2B overhauled (by Superior's "Millenium program) and used AeroRecips 160HP STC.

Does anyone know anything about using auto fuel in this engine??

Thanks in advance! Rick

[cubdrvr]

I ran Pawnee's for 8 years in my ag operation strictly on unleaded auto fuel ( 0-540......low compression engine). It was a gravity flow system as in the cub. I mixed 2 gals. of Marvel mystery oil to 1000 gals. gas. The only problems I ever experienced was on extremely hot days the engine didn't want to idle smoothly........but never a problem under power.

[PA12driver]

0-320 a2b for years and ran what was then "regular" car gas I believe that the advertised octane was at that time 89? I have been told that since then 15years ago that "they" have changed the way they do the octane ratings? I put over 3000 hours on the engine and the only work I did was unrelated to the fuel. I was careful to lean properly (50 degrees rich of peak) and not shock cool the engine! this plane was flown regularily and I had no problems, remember the 160hp engines have a higher compression piston and they tend to run hotter. I am no chemist or economist but relative to the cost of engines the fuel is still pretty inexpensive? Also compared to good scotch, house paint, perfume, even soda pop?

I would love to be in Austria flying one day!

Tim

[Cubus Maximus]

I used 91 Octane unleaded auto gas for a number of years in my O-320 A2B with no problems. I would throw in 6-10 gallons of 100LL every 4-5 tankfulls of auto gas just to throw a little lead in the system. I also put in some Marvel Mystery Oil after every fill up (plus a pint of AvBlend every 25 hours). Even on hot days, there was never a problem. The PA-18 is not nearly as prone to vapor lock as a low wing aircraft due to the gravity feed.

The O-320 B2B 160hp engine is capable of running on 91 octane Auto or higher. The 150 is nice in that it will eat just about anything.

As an aside, we were looking at a 43 L-2M Taylorcraft Grasshopper yesterday. The little C-65 (which get's it off in 500 ft or better) will take anything down to 73 octane! Whoa, sounds like Benzene from Tajikistan will even work in this cute little bird.

Brad

[Crash]

I have run all types of fuel in my 160HP PA-18 in the last ten years and here's what I've noticed. Regular 87-89 octane, (especially out in the Alaska bush) makes the engine still run even after pulling the mixture and shutting off the mags. It just keeps kicking over and won't shut off (too much compression). My buddie's 150hp Cub sitting right next to me shuts right off. The trick I found was to run it up to 1000 - 1200 RPM for a few seconds then pull the mixture without closing the throttle. Texaco Super works like Av gas and shuts right off. It also picks up 50 more RPM after a few tank fulls. Av gas just has too much lead and gums up the rings and lead fouls the plugs. I see this when cleaning the plugs. Crash

[SuperCub MD]

Other than the run on problems previously mentioned, car gas is much more economical. 87/89 octane seems to run about a dollar a gallon cheaper than 100LL, at least around here. 1 dollar per gallon at 8 gph times the 2000 hour life of the engine is $16000. If you were really smart, (I'm not), you would take the money you save on every fillup and put it in the bank. Use some of the money at 1000 hrs to have the valves done, and it should be trouble free up to TBO. At TBO you should have enough money for a good overhaul. Needing to run 91 in 160's and 180's makes for less savings, but it should still add up quick. Also, cheaper fillups mean more flying, and more flying means a much safer pilot.
Mark Drath


P.S. to Brad, I almost bought a L2M once, If they still have all the glass, the rear swivel seat so your navigator can spin around to look out the back and work at his desk, and the spoilers, they are cool little planes. I ended up buying a Cub instead though, go figure.

[SuperCub MD]

I forgot something, some people run 100LL in one tank and cargas in the other. Take off and land with 100LL, cruise with cargas, just to be safe, and to avoid the sputtering problems on shut down and start up. Also then the 100LL sits on all the seals and hoses in the system when not flying, the best of both worlds. Being able to manage you fuel system more precisely is yet another reason not to have the silly spam can both type system.
MD

[Cubus Maximus]

Mark, on your PS: Yeah, this L-2M has most everything. The full observer glass, swivel seat etc. (no heavy field radio and atena crank for talking to the arty boys though.) This one is in great shape, the engine has been majored (not run yet), the wings and fuse rebuilt and covered and the guy wants 12k for it. Not bad! He just decided to quit flying as he has too many retirement projects, can't hear anymore and his peripheral vision is going. When he wants to get it out of his system now, he goes to Arizona, rents a sailplane with instructor and wrings it out for a few hours. Done for the year. If I had 12k available, the plane would have been gone yesterday. Oh, he got rid of the spoilers and the wing has stall strips instead. Great performer! (6 inch wheels, 8:00x6 tires and auto stc as well) It's a poor man's Super Cub.

Brad

[SuperCub MD]

Oh why don't I have some disposable income. Make sure whoever buys it checks the primary structures real well, (wings, ailerons, tail feathers), some were wood, some were metal, and could be rotted. But can't complain to much for 12 large with a fresh engine. Tell whoever gets it to give me a call if they want the spoilers reconnected, I seem to remember researching it, and found I could get them legally operational again. (They originally had to be deactivated for civilian registration)
Mark Drath

[supercubc37]

We've run auto gas for years in the aircraft we've had (1964 172, 0-200 powered cuby, 0-320 powered 150 TD) and the only thing we've found is that you have to be careful of is flying in the spring time on winter blend fuel. For those of you that forgot that the lower reed vapor pressure of the winter blend fuel the potential for vapor lock is increased. We had a guy put a 172 in a bean field last year for that reason. Other than that works great.

Matt