100ll

[thejackrabbit]

anybody running 100LL gas in their 2 strokes? whats the general opinion?

 

[webmaster]

I used to run 100LL av gas in a kx250 and a 4 stroke years ago. I also used to mix it with Race Gas to save money. And I was mixing it with pump gas to get the ethanol percentage down in recent years.

You will hear a lot of negative things about it from folks who have never used it.... Made for airplanes running at constant rpm etc...

My experience is that it works okay by itself - but throws the jetting off a tad as the specific gravity is different from pump gas.

I have found that mixing 100LL with ethanol free premium pump gas makes it "very happy". I go for a 50/50 mix if the premium has ethanol to reduce the overall ethanol content. And if the pump gas is ethanol free - I can do less 100LL in the mix.

I see that you are in PA... You can find listings for stations that sell ethanol free gasoline here :

http://www.pure-gas.org/index.jsp?stateprov=PA


jeff

 

[thejackrabbit]

do you think should try it at 50/50 with 93 so that I'll have 5% ethanol, or should I mix it with a lower octane?

 

[(F5)]

lead is a fantastic octane booster. Add a bit &octane will raise. Add a lot & it will raise a little bit more. Add heaps & it will raise maybe only a smidgen. Av has heaps to avoid detonation problems in planes which would be more than a bad day.

Mixing with lower octane will bring better than the average of the two octanes. Octane is only a small part of a fuels worth. Running a high octane in a mid to low compression engine (anything std) will give no benefit at all), but if you can get rid of ethanol it must be a good thing.

 

[webmaster]

Chevron premium mixed with 100LL would be my choice.

If you are looking at buying av gas you should also look at having your squish dialed in. Big bang for the buck. Ron at rb designs is highly recommended.

Jeff

 

[webmaster]

lead is a fantastic octane booster. Add a bit &octane will raise. Add a lot & it will raise a little bit more. Add heaps & it will raise maybe only a smidgen. Av has heaps to avoid detonation problems in planes which would be more than a bad day.

Mixing with lower octane will bring better than the average of the two octanes. Octane is only a small part of a fuels worth. Running a high octane in a mid to low compression engine (anything std) will give no benefit at all), but if you can get rid of ethanol it must be a good thing.

It isn't just the octane in this case - you are blending two different base fuels plus their additive packages.

And yes, the octane will be boosted by the lead. Back in the mid 1970s in the U.S. when unleaded regular came on the market - premium was still leaded so we could play the truck to mix the leaded premium with the unleaded regular to get something with higher octane than the premium... But they quickly cut the lead content in the premium to negate the gains, eventually removing all the lead in the premium altogether.

You make a good point on the compression and the engine greatly benefits from a head machining/cleanup to dial in squish and compression...

Reminds me that I need to head over to the station near me that sells E0 (no ethanol) premium. I bought several steel cans (jerry cans). I use this for the motorcycles and all my lawn & power equipment (blower, mower, pressure washer, generators etc.)


jeff

 

[thejackrabbit]

In my county its the law that E10 must be sold , I have to travel 30 minutes to get E0 and even then its 87 octane so I have to blend that with some of the race gas the same station sells. my buddy lives right by an airport so for his benefit and mine as I travel there anyway to ride, I figured 100ll might be a viable choice

 

[husley]

Ran it in my Trials bike when we were above 6000'. Helped reduce the loss of power due to altitude

 

[nknudsen]

Here's a funny one. My buddy runs a local airport and had a fellow stop by with his street bike to get a fill of "jet fuel". The cycle guy had heard about it on the internet. I guess to him 100LL is the same as Jet fuel. He was even arguing with them to fill it with jet fuel (basically diesel) but they finally got the point across to him. Duh!

 

[(F5)]

And the same guy will be telling his mates how he filled up with Methanol or somesuch rocket fuel & his bike was doing uncontrolable wheelies in 4th. Yeah heard them all, fortunately people tend to grow out of it. Or get slapped down enough by uncharitable grumpy cynics. I think of it as a public service.

 

[iajim]

My personal opinion is stay away from the av gas, just use a 50% mix of premium pump gas and racing fuel. No, I have never used av gas, my reasons are b/c (1) av gas octane is calculated using a different octane engine, 100 octane av gas is more like 97/96 octane in a research or motor octane engine. (2) av gas has a much lower vapor pressure, 5.5 to 7.5 on average, regular or premium pump gas is 9.0 (3) spec. gravity is different (4) you're still purchasing a product that was made for a 4 cycle engine, mix some oil w/it and you're not much better off because of the higher amount of carbon (oil). You don't need the carbon, just the lubrication. If your engine really needs higher octane b/c of high compression or advanced timing go with the race fuel, a lot less headaches. Consider the race fuel as an upgrade. By the way, my information comes from the years I spent working in an oil refinery laboratory. As I've said before, E10 works fine in a Dodge or Toyota and Av gas works great in a Cessna, just don't try to mix and match.

 

[Brian VT]

Lucky to have Premium E-0 available at the pump in my town again. I was buying Sunoco race fuel @ $8/gal., then 100LL for @ $6.
Even our Liberal Governor is against ethanol in gas. He said it killed his chainsaw.