av gas/100 low lead

[1300obo]

my oldest son is working at a small airport while he gets his instrument and multiengine ratings and he apparently has access to free av gas. i guess they discard the 5-10 gallon samples they test and he gets it for free. has anybody used this stuff in small engines or even old 60's and 70's cars? i'm thinking i may try it in place of the 93 ethanol free ive been using to mix for 2 stroke stuff. from my limited research on the internet there seems to be a lot of people using this stuff in lawn mowers and other small engines

 

[Bent77]

Use to run it through an old Briggs mower. It had a straight pipe and a milled head. Weeds were no problem!

 

[1300obo]

Yeah, so I'm thinking I'll start out trying it in the weedeater and blower and if nothing blows up see how it does in the pressure washer. What about topping off a partially full truck 3/4 full of 87 to just give it an octane boost?

 

[Bent77]

Probably won’t do much, not enough squeeze

Small engines like it though

 

[1300obo]

Probably won’t do much, not enough squeeze

Small engines like it though

But it won't hurt, right?

 

[nvrenuf]

Isn't the AV gas octane rating scale different from automotive fuels?

 

[fastazz81]

We used to run it in are stock class circle track cars.

 

[nvrenuf]

Octane rating aside, avgas does have lead in it which won't play well with O2 sensors or catalytic converters.

 

[Blue85]

I think the octane is rated the same as for automobile gas. 100LL shouldn't hurt any engine that doesn't have a catalytic converter or oxygen sensor.

 

[Bent77]

But it won't hurt, right?

Octane rating aside, avgas does have lead in it which won't play well with O2 sensors or catalytic converters.

Other than that, no

 

[1300obo]

Ok thanks guys, I'll keep it to the small engines

 

[ZooMad75]

Sure would be handy if somebody pissed you off. 5 gallons of leaded fuel would brick a catalytic converter in short order. Just saying, take that info however you see fit.

At a shop I worked at in college we had a lady that found some leaded fuel and dumped in her Jetta. Made it to Denver before the cat clogged up completely. We didn’t know it was leaded fuel at the time, but the engine would not run until we popped the head pipe off at the manifold. The cat was melted solid. She admitted to getting the leaded fuel.

 

[Barrman]

Besides the leaded thing. It will also foul your spark plugs. The lead will stick to the electrode and build up over time.

 

[1300obo]

Sure would be handy if somebody pissed you off. 5 gallons of leaded fuel would brick a catalytic converter in short order. Just saying, take that info however you see fit.

At a shop I worked at in college we had a lady that found some leaded fuel and dumped in her Jetta. Made it to Denver before the cat clogged up completely. We didn’t know it was leaded fuel at the time, but the engine would not run until we popped the head pipe off at the manifold. The cat was melted solid. She admitted to getting the leaded fuel.

I'll keep that in mind, lol. I'd have to be pretty spun up to do that

 

[1300obo]

Besides the leaded thing. It will also foul your spark plugs. The lead will stick to the electrode and build up over time.

So will it foul a lawnmower plug too and why wouldn't it be an issue in the aircraft? Or are you talking about a modern truck engine?

 

[Bent77]

So will it foul a lawnmower plug too and why wouldn't it be an issue in the aircraft? Or are you talking about a modern truck engine?

We ran lead only in a lot of stuff. It takes awhile. If you’re doing seasonal maintenance you’ll never see the difference

 

[1300obo]

We ran lead only in a lot of stuff. It takes awhile. If you’re doing seasonal maintenance you’ll never see the difference

Makes sense, thanks

 

[70jimmy]

Good info. Last time I ran av gas was well before anything I drove had cats.

 

[eodcoduto]

You have to make airplane noises while mowing with that gas, state law!

 

[Barrman]

Airplane engines operate at full throttle and a very high load on every take off and climb. Then in cruise about 70%-90% full throttle and load. Cruise power is normally set by leaning the fuel mixture to achieve a desired cylinder head temperature. The lead prevents detonation in all of those situations. Decent, landing, taxi and idle are pretty much just idling with no heat being generated inside the air cooled engine. If the pilot doesn’t lean out the fuel mixture after landing or any time when idling. The bottom spark plugs will and do foul during normal operation.

I am a member of a flying club. I have found it common to get in a plane flown by others who obviously don’t lean on idle and have misfires. Piston powered planes have two seperate magnetos with two seperate plug wires and plugs. That is done for redundancy. A normal preflight run up is to let the engine warm up while taxiing to the take off end of a runway. Rev to 1700 rpms and turn off each ignition system. The rpm should drop no more than 50 rpms. The club planes drop more than 50 about half the time. When that happens I just lean the mixture until it heats up enough to burn the lead off the plugs and the rpm’s climb back up to at least 1650 and all is smooth. Sometimes the plugs are too fouled and I don’t get to fly that day.

So, back to the original question. Lawnmower, go for it. Anything air cooled and run wide open with a load will be fine. Liquid cooled, mixing should be ok but 100% might cause fouling of the plugs.

I also can’t run it in my multifuel M35A2. A big data plate on the dash says NO. I put some in to thin out the used motor oil one time by accident with no issues. But apparently running 100% a gas will cause a pretty blue flame out the stack which could cause issues for anything or anyone in the back. I’d love to see someone else do it though.