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AV Gas vs. Race Fuel????

R

Ride_The_Rockies

Well-known member
Jun 19, 2002
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Utah
As a matter of fact, I see airplanes falling out of the sky all the time and this is due to dry fuel.

Its funny how you mention this. Maybe not because of dry fuel, but maybe too wet, as in too much water.

"NTSB: Watered down fuel caused crash that killed 2 men"

GREEN RIVER, Emery County — A helicopter crash that killed two Utah men last year was likely caused by a number of factors, including watered down aviation fuel, according to federal investigators.

http://www.ksl.com/?sid=37067704&nid=148&fm=home_page&s_cid=toppick3
 

kanedog

Undefeated mountain clutching champ of the world.
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Oct 14, 2008
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Dont mention water in avgas on this forum. Some of these clown snowesters will turn water in avgas into a worldwide epidemic that only be solved by snowmobile aftermarket companies.
 

klpilot

Well-known member
Lifetime Membership
Sep 8, 2008
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seattle
Its funny how you mention this. Maybe not because of dry fuel, but maybe too wet, as in too much water.

"NTSB: Watered down fuel caused crash that killed 2 men"

GREEN RIVER, Emery County — A helicopter crash that killed two Utah men last year was likely caused by a number of factors, including watered down aviation fuel, according to federal investigators.

http://www.ksl.com/?sid=37067704&nid=148&fm=home_page&s_cid=toppick3

I hope you're trying to be funny... if not I'll explain...

In my experience as a commercial pilot for quite few years 100LL has been exceptional. Extremely consistent and resistant to failure over long term storage. It's quite common for it to sit for years and run great in piston airplanes.

THIS ACCIDENT WAS NOT CAUSED BY AV/GAS. It was caused by absolutely horrible pilot decision making. Nearly all aviation related accidents happen on the ground prior to flight as in this case. And they are typically very easily avoided. Prior to every flight and after every fill up all pilots (with half a brain) check their fuel. It's one of the more simple things that we check and takes about 30 seconds. The fuel isn't the problem. It's a leaky fuel system that allows rain water in. Every aircraft fuel system has sumps at the lowest point of every tank and fuel bowl. We put a little clear cup or tube and simply press the sump. The water is extremely obvious to detect. It looks like jelly beans in the bottom if the cup. Judging by the huge amount of water in this guys fuel storage he never checked his fuel. And it was likely allowing rain water in for quite some time.

It's no different than any fuel. You pour water into it then and dump that into your fuel system and surprise... your engine won't run on water.

I have been running 100LL in mod two stroke sleds since 1997. Absolutely no problems.
 
A
Nov 26, 2007
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For turbo sleds av gas is excellent fuel. It is certified to be over a certain octane level, thats not to say that some blends don't have better octane level than others but it will always be above the certified level. Av gas also has a slower burn rate than race fuels or gasoline and there for tends to chemically retard your timing slightly helping to keep deto at bay. The other thing is that av gas is very clean burning. It is designed so that it can be burned at rich mixtures without fowling plugs as aircraft have mixture controls and are some times ran at fairly rich mixtures on take off at low altitudes.
 
S
Dec 12, 2013
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The short of it is Avgas is good and cheap. Comparing octane levels of avgas and racefuel is not very strait forward. 100LL Avgas is rated by two measurements, a lean mixture rating of 100 octane and a rich mixture rating of 130 octane, to keep it simple it is rated by the lean method. The actual motor octane is around 104-106 which is different than the research octane which is usually higher. Like a Sunoco 110 which is only 105 motor octane.
http://www.racegas.com/fuel/compare Avgas does have lead in it which acts as a lubricant so it is not a dry fuel. A dry fuel would be a gasoline ethanol mix like an E85 you get at the pump. The bang is good for the buck too, I just bought a couple of drums at the local fuel distributor for $5.11/gallon and that is in Washington State. And yes it also smells great.
 
V
Nov 23, 2015
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I've ran both. A 50/50 mix of avgas and 91 worked without any flaw. As for the race fuel I ran some VP 110 and some Tracktek TT111L from the Polaris shop in west both at a 25/75 mix. SO avgas cost me about 6.70 a gallon so 10 gallons of 50/50 mix would be 5 gallons = $33.50 for the avgas plus the cost of 91 (3.00?) at the pump (33.50 + 15 = 48.50) for a 10 gallon tank. The VP 110 cost me about 8.50 per gallon so 2.5 gallons of vp and 7.5 gallons of 91 =(21.25 + 22.50 = 43.75) for a 10 gallon mix. So on the average fill you save enough to buy a monster and a pack of jerky by using race fuel PLUS by using race fuel you only have to tote around half as much. These are the mixes I run. This works for 7-10 ponds of boost depending on setup.
 

Iceman56

Well-known member
Premium Member
Nov 27, 2007
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I've ran both. A 50/50 mix of avgas and 91 worked without any flaw. As for the race fuel I ran some VP 110 and some Tracktek TT111L from the Polaris shop in west both at a 25/75 mix. SO avgas cost me about 6.70 a gallon so 10 gallons of 50/50 mix would be 5 gallons = $33.50 for the avgas plus the cost of 91 (3.00?) at the pump (33.50 + 15 = 48.50) for a 10 gallon tank. The VP 110 cost me about 8.50 per gallon so 2.5 gallons of vp and 7.5 gallons of 91 =(21.25 + 22.50 = 43.75) for a 10 gallon mix. So on the average fill you save enough to buy a monster and a pack of jerky by using race fuel PLUS by using race fuel you only have to tote around half as much. These are the mixes I run. This works for 7-10 ponds of boost depending on setup.

You do realize most the time 110 will detonate the same time, or before Av... Av is usually 104 or more, where 110 can be all over the place depending how good the batch is and how old it is. No need to mix more Av if 110 works
 
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V
Nov 23, 2015
5
3
3
You do realize most the time 110 will detonate the same time, or before Av... Av is usually 104 or more, where 110 can be all over the place depending how good the batch is and how old it is. No need to mix more Av if 110 works

Thats why I stick with VP and Tracktek I don't use cheap off brand race fuel. As for the Avgas I was always told to use more partially because it was cheaper and is usually cleaner than what your going to fill at the pump as far as foreign material and quality
 
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