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-   -   100 OCTANE aviation fuel in gasser (https://www.rcuniverse.com/forum/gas-engines-142/11005338-100-octane-aviation-fuel-gasser.html)

pe reivers 03-21-2012 11:11 AM

RE: 100 OCTANE aviation fuel in gasser
 
Sport, and others:
I did not say TEL did not slow down combustion. It is true. It is still true in 100LL Avgas with about 16 times the lead content that premium gas used to have. The LL (low lead) denomination is a bit misleading. The Avgas is highly poisonous and detrimental to engine cleanliness and the environment. The lead distorts children's mental and healthy brain development as well. That is why DA does not like it at all. European manufacturers do not have to stress this. High quality fuel is available from every pump tap, the lowest being 95 RON (~91PON)
I must stress my point that nowadays High pump octane does not burn equal to the TEL-octane of the past, though octane numbers are the same. The generalized saying that high octane burns slower is a myth. High octane obtained by adding TEL to inferior stock fuel burns slower; modern high octane fuel does not. These are the two different things.
Whilst Avgas can bring about a performance decrease in high strung engines, modern 98 - 100 gas makes them more lively. ( 4-stroke engines)

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airraptor 03-21-2012 11:43 AM

RE: 100 OCTANE aviation fuel in gasser
 


ORIGINAL: charlie1960

''Octane'' is colloquially used as a short form of ''octane rating''. Named for the ability of octane's branched-chain isomers, especially isooctane, to reduce engine knock

Octane is a hydrocarbon and an alkane with the chemical formula C8H18, and the condensed structural formula CH3(CH2)6CH3. Octane has many structural isomers that differ by the amount and location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (isooctane) is used as one of the standard values in the octane rating scale

Tetraethyllead (common name tetraethyl lead), abbreviated TEL, is an organolead compound with the formula (CH3CH2)4Pb. Its mixing with gasoline (petrol)as an inexpensive additive beginning in the 1920s allowed octane ratings and thus engine compression to be boosted significantly, increasing power and fuel economy. TEL was phased out in view of the toxicity of lead and its deleterious effect on catalytic converters. It is still used as an additive in aviation fuel for piston engine-powered aircraft.

Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. An engine requires fuel of sufficient octane rating to prevent uncontrolled combustion known as engine knocking (''knock'' or ''ping''). Antiknock agents allow the use of higher compression ratios for greater efficiency and peak power. Adding varying amounts of TEL to gasoline allowed easy, inexpensive control of octane ratings; aviation spirits used in WWII reached 150 octane to enable supercharged engines such as the Rolls-Royce Merlin and Griffon to produce 1500 HP at altitude




I think its funny how people look up stuff on the net then copy and paste it as thier own..


WHEW....That should sufice.

TimBle 03-21-2012 11:58 AM

RE: 100 OCTANE aviation fuel in gasser
 


ORIGINAL: pe reivers

Sport, and others:
I did not say TEL did not slow down combustion. It is true. It is still true in 100LL Avgas with about 16 times the lead content that premium gas used to have. The LL (low lead) denomination is a bit misleading. The Avgas is highly poisonous and detrimental to engine cleanliness and the environment. The lead distorts children's mental and healthy brain development as well. That is why DA does not like it at all. European manufacturers do not have to stress this. High quality fuel is available from every pump tap, the lowest being 95 RON (~91PON)
I must stress my point that nowadays High pump octane does not burn equal to the TEL-octane of the past, though octane numbers are the same. The generalized saying that high octane burns slower is a myth. High octane obtained by adding TEL to inferior stock fuel burns slower; modern high octane fuel does not. These are the two different things.
Whilst Avgas can bring about a performance decrease in high strung engines, modern 98 - 100 gas makes them more lively. ( 4-stroke engines)

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exactly. TEL is a neuro inhibitor. Its affects can be measured in the synapse firing in adults besides stunting brain development in children. TEL is one of those products that seemed like a good idea at the time but was really a backward step.

The unfortunately reality of avgas is that is contains a large percentage of Alkylate which is both high in RON and especially MON and therefore has a high AKI, it is slowed down (combustion) by the addition of TEL.

I simply would not advise using AVGAS at a model flying field where exhaust gases will be inhaled by ones club mates. There is no sump to absorb some of the lead emissions.

Not benefit to using avgas for performance, engine longevity. spark plug reliability and numerous health reasons also makes it a non prefered fuel.

I've played around with M3 gasoline and that works quite well. E10 gasoline is not available where I live but if it was I would not hesitate to use it. One just has to make sure you use a E10 compatible 2 stroke oil and don't store the engine with fuel in for long periods of time.
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OliverJacob 03-21-2012 12:13 PM

RE: 100 OCTANE aviation fuel in gasser
 
Any opinions about Coleman 'White Gas' ?

tkg 03-21-2012 12:14 PM

RE: 100 OCTANE aviation fuel in gasser
 
AV gas does nothing to make an engine run better. BUT it does not harm an engine, other than the need to clean spark plugs more often.
As burn speed.... On a very highly tuned piped 2 stroke, I trive AV gas once. The header inside turned from black to gray showing that the fuel was still burning after the exhaust port opened. Went to regular w/o ethnol and 16:1 oil mix. After I set a new track record told the other racers I was using 32:1 oil mix and premium. :D took them about 4 races to figure it out.[X(]

comanche260c 03-21-2012 03:13 PM

RE: 100 OCTANE aviation fuel in gasser
 
SO who ruined there engine on av gas   speak up. I have not heard one person say they used av gas  and  did damage.       

comanche260c 03-21-2012 03:16 PM

RE: 100 OCTANE aviation fuel in gasser
 
http://www.arboristsite.com/chainsaw/191031.htm  I googled avgas in weedwacker

charlie1960 03-21-2012 03:33 PM

RE: 100 OCTANE aviation fuel in gasser
 
never claimed it was MINE........you ASSUMED

OliverJacob 03-21-2012 03:58 PM

RE: 100 OCTANE aviation fuel in gasser
 
I was wondering why there is no one with actual bad experiences using Avgas.
With a full size aircraft you might see some more problems, these get a lot more use then the average RC engine.
So with a few hours each season, there is probably very little lead build up.
And it's always a good idea to stay out of the fumes of anything that burns or smokes. So lead poisoning from your RC engine can easily be avoided.
Also no one knows about the long term effects when breathing the fumes from our glow engines...not wanting to start another discussion about it, al the different forms of glow fuel have not been tested to an extend that we can not absolutely be sure it won't cause any harm.





mach2 03-21-2012 04:37 PM

RE: 100 OCTANE aviation fuel in gasser
 
Well I posted earlier about my negative experience with 100LL. However it was not an rc engine, but a 125cc motocross bike.  Really the only difference in the engines is size and the motorcycle is water cooled. It ran way too hot and smelled like it was overheating, as getting hot enough for me to feel the heat on the inside of legs through my thick pants, under armor pants, long socks and knee braces. If I had continued to run that fuel, it surely would have ended up seizing my engine....

Just my experience.

captinjohn 03-21-2012 05:31 PM

RE: 100 OCTANE aviation fuel in gasser
 
If you read enough you will find the following below.Capt,n PS I agree.

<div class="bbcode_quote_container"></div><div class="bbcode_postedby">http://www.arboristsite.com/images/misc/quote_icon.png Originally Posted by cujet http://www.arboristsite.com/images/b...post-right.png</div><div class="message">There is quite a bit of misinformation about 100LL Avgas. I'll try to address some of this.

1) Avgas contains lead. However, recent modifications to 100LL (under the very same specification) have resulted in a product known as 100VLL (very low lead) It's what is generally available at Avgas pumps now. In other words, much of 100LL sold today is actually 100VLL.

2) Avgas is engineered to vaporize readily, for excellent cold and high altitude performance.

3) Avgas is high octane fuel.

4) Alcohol free unleaded has limited real world anti knock performance. Generally 93 is the maximum number, R+M/2. Without significant engineering, unleaded gasoline is incapable of higher octane. Swift fuels (a 100LL replacement) is an experimental high octane unleaded. It's not available.

5) Due to excellent vaporization, idle, low speed and high speed "jetting" may need to be adjusted slightly leaner with the use of 100LL.

6) Many high RPM engines exhibit a slight loss of power on 100LL. This is generally due to improper fuel/air mixture.

I use 100LL in all my yard equipment. It is trouble free. A perfect example is the lifespan of the primer bulbs on pump gas v 100LL. I have a 12 year old Echo blower with the original primer bulb at my aircraft hangar, still in perfect working order (avgas since new). Where my Echo weed eater at home has been through many primer bulbs with auto gas. I've now switched to 100LL in everything and my fuel system troubles have been eliminated.

Also, when properly tuned, 100LL just runs smoother in 2 strokes at low loads. Mostly due to vaporization issues.</div>

DMAYLE 03-21-2012 05:37 PM

RE: 100 OCTANE aviation fuel in gasser
 
I've been using Avgas for the last 4 years. Basically no smell and I haven't had any negative issues with my DLE 20, Evolution G26, and DA50. All engines run great.

unclecrash 03-21-2012 06:29 PM

RE: 100 OCTANE aviation fuel in gasser
 
Just went and filled up on 100LL it for this years flying. One big plus is it does not go bad like regular gas. Another is it does not stink. Another is it does not kill the carb diaphrams like regular gas. Yes it contains lead but there are far worse things that kill people every day.

TimBle 03-22-2012 03:42 AM

RE: 100 OCTANE aviation fuel in gasser
 
My edits in red

ORIGINAL: captinjohn

If you read enough you will find the following below.Capt,n PS I agree.

<div class="bbcode_quote_container"></div><div class="bbcode_postedby">http://www.arboristsite.com/images/misc/quote_icon.png Originally Posted by cujet http://www.arboristsite.com/images/b...post-right.png</div><div class="message">There is quite a bit of misinformation about 100LL Avgas. I'll try to address some of this.

1) Avgas contains lead. However, recent modifications to 100LL (under the very same specification) have resulted in a product known as 100VLL (very low lead) It's what is generally available at Avgas pumps now. In other words, much of 100LL sold today is actually 100VLL.
<span style="color: #ff0000">100LL contains 0.56 gPb /L. this is in contrast to 0.13g/Pb/L that was allowed in leaded gasoline some 20 years ago. This is more than 4 times the lead content.
Considering that a day at the races would leave a spectator with a severe headache, its stands to reason that spectators at a flying field are well within the affected zone for lead inhalation. </span>

2) Avgas is engineered to vaporize readily, for excellent cold and high altitude performance.
<span style="color: #ff0000">So why does a RCengine benefit from it? It doesn;t because at 150m above the pilot the engine si not going to feel a significant temperature drop</span>

3) Avgas is high octane fuel.
<span style="color: #ff0000">How is this advantageous to a low compression two stroke?</span>

4) Alcohol free unleaded has limited real world anti knock performance. Generally 93 is the maximum number, R+M/2. Without significant engineering, unleaded gasoline is incapable of higher octane. Swift fuels (a 100LL replacement) is an experimental high octane unleaded. It's not available.

<span style="color: #ff0000">Complete crock</span>. <span style="color: #ff0000">Alkylate is a majorcomponet in unleaded and has AKIin excess of 93 and a RON of in the 110 range and MONin the 106Range.</span>

5) Due to excellent vaporization, idle, low speed and high speed "jetting" may need to be adjusted slightly leaner with the use of 100LL.
<span style="color: #ff0000">ow does it have excellent vapourisation when the boiling range for 100LL is narrower than for gasoline. It also has a lower Reid Vapour Pressure, indicating it has much less or no butane in it when compared to gasoline.</span>

6) Many high RPM engines exhibit a slight loss of power on 100LL. This is generally due to improper fuel/air mixture.

<span style="color: #ff0000"><span style="color: #ff0000">This is because the fuel burns slower....</span></span>

I use 100LL in all my yard equipment. It is trouble free. A perfect example is the lifespan of the primer bulbs on pump gas v 100LL. I have a 12 year old Echo blower with the original primer bulb at my aircraft hangar, still in perfect working order (avgas since new). Where my Echo weed eater at home has been through many primer bulbs with auto gas. I've now switched to 100LL in everything and my fuel system troubles have been eliminated.

Also, when properly tuned, 100LL just runs smoother in 2 strokes at low loads. Mostly due to vaporization issues.</div>

Sport_Pilot 03-22-2012 08:49 AM

RE: 100 OCTANE aviation fuel in gasser
 
Here is what Rotax says about aviation fuel in their engines for ultra lights and home built aircraft.




</p>

Aviation Fuels</p>

It is possible but not recommended to use 100LL AVGAS, since the the lead content will increase deposits in the combustion chamber and on crankshaft ball bearings, inducing premature wear. Its higher octane rating does not bring any significant advantage to the engine's operation.</p>

</p>

Desertlakesflying 03-22-2012 10:17 AM

RE: 100 OCTANE aviation fuel in gasser
 
110 race runs realllllllly good in the Evolution 40GX.

Runs smoother, cooler, and produces more power than regular.

pe reivers 03-22-2012 02:16 PM

RE: 100 OCTANE aviation fuel in gasser
 


ORIGINAL: Desertlakesflying

110 race runs realllllllly good in the Evolution 40GX.

Runs smoother, cooler, and produces more power than regular.
Compared to what? Regular? I would not even dare to run that fuel unless at least 4000' up in a mountain range. Tthe 40GX needs 90 - 91 PON octane minimum!
I found no difference whatsoever running the engine on the prescribed 95 RON gas or running on Shell V-power 100 RON gas.
For gas octane ratings, see http://en.wikipedia.org/wiki/Octane_rating



comanche260c 03-22-2012 02:21 PM

RE: 100 OCTANE aviation fuel in gasser
 
OK  I loaded the taylorcraft with av gas today  with 100LL.It has  a Zenoha 26 in it.   Ran like poop.When i gave it throttle  wasnt smooth and  couldnt get it to idle without stalling in 1 minute. Tryed  adjusting needle valves  but  got frustrated, Put  87 octaine in it and   doesnt stall no matter what i do. Ok  why is that?is it the  slower flash in the gas?    motor has ignition built into it ,no electronic  ignition.. Is there a way i could of adjusted timing?   How  about my quadra 75 with eletronic  ignition  will that be a diffrent animal

aussiesteve 03-22-2012 02:36 PM

RE: 100 OCTANE aviation fuel in gasser
 


ORIGINAL: comanche260c

OK I loaded the taylorcraft with av gas today with 100LL.It has a Zenoha 26 in it. Ran like poop.When i gave it throttle wasnt smooth and couldnt get it to idle without stalling in 1 minute. Tryed adjusting needle valves but got frustrated, Put 87 octaine in it and doesnt stall no matter what i do. Ok why is that?is it the slower flash in the gas? motor has ignition built into it ,no electronic ignition.. Is there a way i could of adjusted timing? How about my quadra 75 with eletronic ignition will that be a diffrent animal
It may be all the lead buildup making your piston too heavy :D

There is a lot more to an engines running characterisitics than just "Octane rating". Ignition timing, mixture adjustment, fuel viscosity.
Note that most of the previous mentions of people who ran avgas and were not happy with it - many mentioned poorer running (Including on the chainsaw sites).

OliverJacob 03-22-2012 02:40 PM

RE: 100 OCTANE aviation fuel in gasser
 
You'd have to advance the timing on both engines. The electronic ignition adjusts the timing in relation the the rpm, not to the fuel quality.
Most electronic ignitions have slots on the sensor bracket, you'd loosen the screws and to advance timing you'd turn it against the prop rotation.

warbird addict 03-22-2012 03:08 PM

RE: 100 OCTANE aviation fuel in gasser
 
This issue has been run through the mill and the end result was several rc engine manufacturers stepping in and stating the reason NOT to use AVGAS in their engines as they are LOW compression Engines and are not designed to run on it at all , The RC engines we currently use are designed for optimum efficiency and power using 87 octane regular pump gas, they aslo addressed the issue of coleman fuel which they determined to be too low of an octane rating but the end result in all cases was good ol 87 octane.
On a personal note I use the 87 octane in all my motors and started using some stuff called StarTron an enzymatic treatment which neutralizes the adverse effects of E-10
and much to my surprise it really woke these engines up to the point that they had to be retuned , at which point they ran much cooler and made alot more power as well as ran alot more reliably, additionally startron claims you can't overdose and should their product be determined to have caused a catastrophic failure of your engine they will replace the engine at no cost to you and thats any engine, boat , car, weedwacker, motorcycle, snowmobile, atv, or an rc engine, so far my experience with it has been stellar I leave my carbs wet for extended periods of time with no problems, take em out turn em on and 3 flips later it's running, just my.02

comanche260c 03-22-2012 04:23 PM

RE: 100 OCTANE aviation fuel in gasser
 
thanks oliver not sure i will go with av gas now .seems like a big hassle guess i will add a add aadditive like warbird just suggested on next post THANKS EDDIE

crashprofector 03-22-2012 04:24 PM

RE: 100 OCTANE aviation fuel in gasser
 
We have been using 100LL in all our gassers at the verses this so called gas at the pumps with better results no carb problems now, Great choice u will like it.

comanche260c 03-22-2012 04:40 PM

RE: 100 OCTANE aviation fuel in gasser
 
cash didyou change the timing in your engine

TimBle 03-22-2012 08:56 PM

RE: 100 OCTANE aviation fuel in gasser
 


ORIGINAL: comanche260c

OK I loaded the taylorcraft with av gas today with 100LL.It has a Zenoha 26 in it. Ran like poop.When i gave it throttle wasnt smooth and couldnt get it to idle without stalling in 1 minute. Tryed adjusting needle valves but got frustrated, Put 87 octaine in it and doesnt stall no matter what i do. Ok why is that?is it the slower flash in the gas? motor has ignition built into it ,no electronic ignition.. Is there a way i could of adjusted timing? How about my quadra 75 with eletronic ignition will that be a diffrent animal
The higher initial boiling point means the AVGAS won't atomise very well at cold temperatures unless you some good compression going on. Lycomings, Vedeneyev and other piston engines in full size planes are 4 stroke and have higher compression than your two stroke. The engines fueling system generates a higher fuel pressure to force teh fuel through an atomising nozzle making it easier to burn.


You are going to have trouble with AVGAS at some point down the line but I guess we all have to knock our own heads.
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