How long will AvGas actually store?

[kodiakyardboy]

Octane is a rating of a fuels resistance to ignition and has absolutely no bearing on a fuels potential stored energy...... higher octane ratings will not make more power in an engine unless conditions exist that warrant the higher octane rating. And even then it is the modifications that make the higher octane necessary that are making more power and not the higher octane fuel.

However..... higher octane pump fuels usually have a better additive package than the lower grade cheaper fuels.

Good answer, 100% correct.

 

[whitedogone]

I'm thinking about one of this to store (for a very short time) all the achohol that I don't use in my 2 cycle gas. WDO

http://cgi.ebay.com/JERRY-CAN-GAS-C...5|66:2|65:12|39:1|240:1318|301:0|293:1|294:50

 

[24d]

They have those in five gallon as well as two and a half but thats a little spendy for me.

Later,

 

[Old51AVE]

Avgas

Hello,

Fairly new here and learning lots!

One area I am familliar with is aviation. I work as a A.M.E (A&P in the USA).
I use Avgas in all my 2-cycle equipment, lawn mower, chainsaw, string trimmer etc. I mix 40:1 with amsoil synth for all applications. Yes, it has a superior additive package and can last for extended periods of time. It works well in aircooled engines for which it is designed. It has an extremely low vapor pressure to work well at high altitudes and low temperatures. you used to be able to get basic avgas (colored red) it was 80/89 used on older planes, it is rare now. the standard is 100LL so named because it is 100% iso-octane with a hint of tetraeythl lead. In the USA I belive you can also get just striaght 100 which is green and has even more lead! And yes the coveted 120/130 purple, again rare, for higher compression 'performance' aircraft engines, also with lead. Don't be mislead (pun intended) a fuel can only be 100% octane, anything over is a 'performance' number related to its anti-knock qualities under high compression. Usu it can be increased with additives like lead. Propane has an equivalent performance number of 120, where natural gas has 130..

For you diesel owners, you can even run jet fuel in your rigs!

We test our planes daily for fuel quality and contamination. Usually everything is fine and these 'drainings' have to go somewhere, so needless to say they find good home...

Hope that answers some questions!


D.:greenchainsaw:

 

[mbopp]

Besides octane there is something else to consider - how many BTUs per gallon of fuel is in avgas vs pump gas. Years back when I was in GM school I tracked down some figures in 87 and 93 octane pump gas. I don't have the specific numbers anymore but I do remember the 93 octane gas having less energy (BTUs) per gallon than 87 octane. Higher octanes claim to fame is that you can run higher compression & more spark advance, getting more horsepower in the process.
I don't have the BTUs per gallon of avgas. But I do remember reading about running pump gas in aircraft engines. There is no spec on BTUs per gallon of pump gas but there is one for avgas. And the article stated that pump gas has less BTUs per gallon of avgas. It may seem insignificant until you figure the range you have - IIRR the figure was 10% less range on pump gas.
So - if you run avgas does this make the saw run richer since you're putting more BTUs in per measure of fuel?
Side note - the Navy was looking into a less flammable fuel for its jets after the (Forrestal?) fire. The resulting JP-5 is less flammable than JP-4, making mid-air restarts a bit tougher. But a side result is that JP-5 has more BTUs per pound than JP-4 so the aircraft got a boost in range for the same fuel load.

 

[24d]

Does anyone know how much performance could be gained with an engine designed for and running 100 octane over 93????

Later,

 

[Old51AVE]

There are less btu's in higher octane fuels, generally.. The only time you get a boost in btu's would be to use jet fuel in your diesel equipment.. Not recommended for use in the summer, straight, (runs to hot) and it has lower lubricity, so mixing with some oil or lube is important as well.

Jet fuel is safer nowadays, as mentioned, it is only relly dangerous when atomized.. Some of the old military jet grades were cut with naptha and other agents, great for the afterburners and power but really volatile stuff, as well!

D.

 

[Old51AVE]

Does anyone know how much performance could be gained with an engine designed for and running 100 octane over 93????

Later,

Umm.... About 7%, assuming 100% efficiency!

D.:hmm3grin2orange:

 

[RiverRat2]

I'm actually more interested in if it actually makes less power since it burns cooler.

Higher Octane fuels ie: racing gasolines work best in High compression motors,,, I say this from years of outboad drag boat Pro Gas/Modified class racing,,, we would see harder acceleration which yielded quicker ET's,,,,
what I saw that struck me funny that top end speed gains were negligible

JMHO the higher octane racing gasoline (114 octane) is a waste of money in a stock compression/porting application,,,, the av gas 100LL octane or (100) lower octane race fuels should be OK for a non catalytic muffler saw especially over ethanol blends which adversely affect carb systems on a saw when they start to degrade which unfortunatly happens pretty fast especially if you leave it in your carb/saw,,,,,,

As far as Alcohol Motors,,,, they do run cooler,,, make Gobs of power,,, but the fuel delivery system must be upgraded (larger ID plumbing & fuel pump) to deliver the higher volume required to keep them from leaning out,,,,, A higher energy ignition system is needed as well

 

[litefoot]

Higher Octane fuels ie: racing gasolines work best in High compression motors,,, I say this from years of outboad drag boat Pro Gas/Modified class racing,,, we would see harder acceleration which yielded quicker ET's,,,,
what I saw that struck me funny that top end speed gains were negligible

JMHO the higher octane racing gasoline (114 octane) is a waste of money in a stock compression/porting application,,,, the av gas 100LL octane or (100) lower octane race fuels should be OK for a non catalytic muffler saw especially over ethanol blends which adversely affect carb systems on a saw when they start to degrade which unfortunatly happens pretty fast especially if you leave it in your carb/saw,,,,,,

As far as Alcohol Motors,,,, they do run cooler,,, make Gobs of power,,, but the fuel delivery system must be upgraded (larger ID plumbing & fuel pump) to deliver the higher volume required to keep them from leaning out,,,,, A higher energy ignition system is needed as well

Ahah! Now your avatar is starting to make sense to me.

 

[777ER]

Hello,

Fairly new here and learning lots!

One area I am familliar with is aviation. I work as a A.M.E (A&P in the USA).
I use Avgas in all my 2-cycle equipment, lawn mower, chainsaw, string trimmer etc. I mix 40:1 with amsoil synth for all applications. Yes, it has a superior additive package and can last for extended periods of time. It works well in aircooled engines for which it is designed. It has an extremely low vapor pressure to work well at high altitudes and low temperatures. you used to be able to get basic avgas (colored red) it was 80/89 used on older planes, it is rare now. the standard is 100LL so named because it is 100% iso-octane with a hint of tetraeythl lead. In the USA I belive you can also get just striaght 100 which is green and has even more lead! And yes the coveted 120/130 purple, again rare, for higher compression 'performance' aircraft engines, also with lead. Don't be mislead (pun intended) a fuel can only be 100% octane, anything over is a 'performance' number related to its anti-knock qualities under high compression. Usu it can be increased with additives like lead. Propane has an equivalent performance number of 120, where natural gas has 130..

For you diesel owners, you can even run jet fuel in your rigs!

We test our planes daily for fuel quality and contamination. Usually everything is fine and these 'drainings' have to go somewhere, so needless to say they find good home...

Hope that answers some questions!


D.:greenchainsaw:

There's 80 (red) and 100LL (blue) easily found at most airports here in the US... 100 (green) is just harder to find.

Jet fuel is basically cleaner fuel with more additives than plain diesel fuel Hence no problem running in rigs or diesel engines.

I was sitting in a pickup truck waiting for a ERJ-145 to come in for maintenance and saw this aircraft fueler truck stop on the ramp, takes the over-the-wing backup nozzle (which is used when the SPR is disabled or on MEL) and bring it to the front of the truck and filled the truck's engine tank up from it's own huge 'Jet A' tank in the back

You can even use home heating oil in a diesel engine.
My bro does this for his jeep since it's cheaper than diesel from the pumps and it's low or tax free fuel. It's dyed red to deter it but cops don't check diesel personal cars, they check the commerical rigs with a clear glass tube and if it's dyed red, they fine the driver a hefty $$$ ticket.

A&P here

 

[Mad Professor]

Be careful you don't get caught running any AV fuel/heating oil in on-road vehicles, Mr. Tax man will not like it.