Once in awhile I am going to need another way to up octane when I run out of Toluene or race gas. I know it would be bad on the cats if I ran it all the time but is there any problem with adding some once in awhile?

Thanks,
Mark

 

cant be any worse than me running 112 sunoco leaded in mine.

 

It's always a good subject for debate....

I run it 50/50 in my offroad VW sandrail with 2110 engine and 9.5 to 1 compression.

It is cheaper cause theres no road tax, just tell them at the airport your running it some offroad toy. They won't put it directly in your truck but they will fill gas cans ."PITA"

Smells different, will turn your pipe gray, it sure won't detonate.

"They say" Whoever "they" are that the octane rating is different and there would be problems. Airplanes run at constant speed and all that.

I have been running it on and off for years and never seen or heard of a problem. Don't forget lots of airplane engines run 30LBS of Boost and detonation would be a bad thing. So would carburator ICING.
Airplane owners frown on engine problems while there in the sky.
I guess there just picky about things.

 

It is just a high octane fuel with alot of lead in it. I wouldn't run a leaded fuel through an engine designed for 91 or 93. One of the tugs (small tractor for towing airplanes) at work went down. We pulled the head off of it, and found 3 burnt valves, and a hole in a piston. The tops of the pistons were severely coated with lead, as were the plugs. What was left of the valves was also coated with lead deposits.

Just a little info in case anyone wants it. Airplanes are designed to run on it because they have a high compression engine, and fly in very cold temps compared to running it in your car. I work on airplanes, and have run that stuff in old carbed engines, with high compression. No problems with those.

 

AvGas LL is 110 Octane, I'm pretty sure, at least that what I think I put in mine.
My plane is not turbocharged (Cessna 172R, with a Lycoming engine) but a some are and they don't seem to have any problems. A thing to consider is a plane runs at much higher altitude (there is a **** to lean it out or richen the mixture, once at altitude we lean it out a bit) and manifold pressure is much different on a plane, expecially one with a variable prop (where you run constant RPM and play with the M pressure to adjust the power).


Just a thought, for real help with this, read the section of the Flight Manual Training book on constant RPM engines, I don't fly that kind of plane so I really don't know much about them, I studied it once to get my ticket, but that was 20 years ago.

G

 

Maybe I should clarify.

All I have ever used around here in Colorado is 100 Low Lead AVE GAS and thats what I mix 50/50 with 91 pump which is about the best you can find at a pump. Can't really speak for other mixes.

In the winter they sell this ethanol mix everywhere which works ok but has lower BTU and power rating. I mix with that to and have done a few tear downs and seen no problems on my engines.

 

FWIW, in the world of dirt bikes, the criticism of Av Gas is decreased throttle response. Works well at preventing detonation, though.

 

If it doesn't foul out your O2 sensors or Cats and raises octane then what the hell it should be ok to use it.

 

Straight av gas is very areomatic.It will cause you more problems than not running it.You can get into hi rpm stumbles and misses and it can act like it is vapor locking[yes even in a EFI vehicle]Also av gas is rated on the lower of the 2 methods.Were as the pump gas is on and average of them both.IF you rated 11ll as pump fuel it would rate around 80.The only thing that saves the high comp street engine is the amount of lead in it.Which as you have already read lead fouls things.
If you use it mix it with reg pump fuel to make it more stable.Stan