mustangman177

Need some advice from the" Fuel Brewing People" out there

Been doing some reading on "Brewing" your own fuel and looks economical compared to the prices of fuel in hobby shops. My question is how to "Brew".

AsI see it, the 2 main components are: Castor oil and Methanol, mixed at % of 20% oil to 80% methanol ?

I have a gallon of Klotz's Benol oil. http://www.klotzlube.com/smallprodimages/BC-175.jpg, Where do I get the Methanol to mix with ?

ANY other technical data on mixing would be GREATLY appreciated. I've been buying fuel for 20 years -mostly Byron's 15% Nitro., but the cost is getting too high. Last time was around $20. a gallon. Sure bet it has gone up since then.

Thanks for your help

mustangman177

Just read the "Home Brewing Fuel" post after submitting my post, and being over 300 posts long is quite informative. The general concensus is that the "Mix" below works ?

Didn't take the time to read all 300 posts, but Methanol and Nitro. can be obtained from a speed shop, Klotz's KL-200 is the oil of choice. Is this similar to their Benol oil ?

My 4 mix:

16% Klotz KL-200

4% Racing Castor

10% Nitro

70% Methanol

Best fuel money can buy

Flyboy Dave

My Feedback: (21)

....yep.

mustangman177

Thanks Dave...... By making your own fuel, What would you say is the cost per gallon for brewing ? Would like to compare to buying pre-mixed fuell.

Flyboy Dave

My Feedback: (21)

....I haven't mixed my own fuel for over 17 years, but when I did it was 15% nitro
and 15% oil....1/3 castor and 2/3 Klotz. Back then it cost 6 bucks a gallon. Nitro has
gone way up since then. []

FBD.

XJet

There are bound to be arguments about this but I would certainly not say that Klotz KL200 was the best oil money could buy.

There are oils which provide greater protection at lower percentages (thus giving longer engine runs and life).

Some of the more advanced synthetics have greater lubricity, film strength and superior temperature characteristics to those more commonly found in the USA.

There's nothing wrong with Klotz but why use 20% total oil when there are others who get better performance and longer engine life using half that much of a "better" oil?

hvymetalalchmst

i read somewhere (internet, so dont treat it as a fact instantly) that oil should be between 8-12%. The site said something about at less than 8%, there is a shortened life, at more than 8%, there is almost insignificant difference in engine life, and at overly high percentages (they stated around and above 20%), there are problems in its own.

the site mentioned that due to high oil, you can be running your engine excessively lean because of the oil which removes both heat and has a high chance of contaminating/poisoning the glow plug filament, requiring leaning out so your engine can sustain combustion. which in that case, there surely would have negative effects going too high or low

im about to invest AU$200 into ingredients to hombrew making around 30L of fuel. Down Under, it costs AU$15/L, and mixing myself cuts that price in half.

these are just a few things i came across that i thought was a little intriguing.

mustangman177

What is the current price for Pre-Mix fuel ?

The last time I bought fuel, (late fall) it was $20.00 a gallon for Byron's 15% Nitro, 18% oil. Has it gone up since then ? I thought $20. was excessive.

This was before the Winter Olympics and China was supposedly cutting back on Nitro production to "Clean up the Environment " for the Olympics. (That's what the retailer selling me the fuel told me).

How about the cost for other brands: Cool Power, Omega and others ?

balsaeater

Its true that very good synthethic oils can go down to ~8% However the timing of engine changes as oil drops so some engines require more nitro or more oil to change the timing back as glow plugs timing are not so precise .
Varies from engine to engine mostly to do with compression ratio so low compression ratio engines are less likely to suffer these issues.The timing issue effect on spark ignition engine that is running on a glow mix is most unlikely to happen with low oil content as the spark ignition sets the timing better than glow plugs can

I prefer to stay at 10% synthetic EDL for 2 stroke or 12 % synthetic EDL for Saito 4 stroke and no castor at all

Balsaeater

carrellh

At one of our local hobby shops, fuel with 15% nitro is $16 to $19 per gallon. They sell Cool Power, Omega, Ritch's Brew, Wildcat, and possibly another brand or two.

I have no idea if you can save much by blending your own. I know a few drag racers, so I could get the nitro and methanol, but I've never priced it.

It takes me 'several' Saturdays to use a gallon of fuel so I guess the fact that fuel prices have almost doubled since 2006 does not have a huge impact on me like it does on people who use a gallon or more per week. Buying 3 cases is a chunk of cash at once but it lasts me a few years.

Lille-bror

I have tried mixing fuel with different oil %. The oil was AeroSynth2 and AeroSynth3 – should be a really good synthetic oil from Europe.

I found out, that 2 stroke .46 size engines, runs ok on only 12 % oil. I couldn’t measure any increase in RPM compared to a mix with 18 % oil. The one thing I found out was a metallic sound from my engines – not a healthy sound I’ll guess…
I don’t know if that negative effect only is present with AeroSynth oil.

From now on, I’ll stick to 18 % top quality synthetic oil.

downunder

I vaguely recall reading that too but I think it was on a car web site so it doesn't apply to plane engines. Within reason you almost can't have too much oil. My general fuel for testing a new (to me ) engine on the bench is 75/25 all castor and they've all run perfectly to the point where I wouldn't hesitate to fly them with that fuel. Oil removes very little heat and, with castor at least, I've never had a contaminated plug even after 30 or 40 hours of running.

I'm not sure of the latest price but here in Adelaide I was getting methanol for $1.25 a litre and castor for $8 a litre so an 80/20 mix was costing around $3 a litre. Of course if you use any nitro then that'll up the cost considerably. You can get castor for about the same price in Melbourne too.

XJet

That sounds *awfully* expensive.

Here in NZ (where the Kiwi peso buys next to nothing), I can buy a whole drum of methanol (209 litres) for around NZ$300 and a really good oil will cost about $20/litre.

Nitromethane is about NZ$25 a litre

So 30 litres of fuel with 12% oil and 5% nitro (what I usually fly) would cost only NZ$145 or so. I think that's probably about A$120.

You can save some real money by using a smaller percentage of a better quality oil when brewing your own fuel as even a cheap oil (Coolpower or Klotz) is about fifteen times as expensive as methanol.

balsaeater

The NZ peso is about 1 NZ $ equals ~ euros € 0.30cents ball park $0.40 cents USA

me in high tax euroland if I bought ~200 liters methanol drum delivered to the door it cost €330 euros or about ~ 3 times (edit coorection not 6) your prices but maybe earning here are a bit higher so its still not a huge cost factor for engines up to 30cc.It about ~€7 euros a liter ~$10 USA a liter ~$NZ 21 a liter
I chose to buy 4 UK gallon a time in 4 one gallon containers and that about ~30% extra cost or ~€10 a liter

If I could drive some few hundred miles to collect the prices would be 20% cheaper but i cant get insurance to carry that much fuel and personnaly I dont want that ~200 drum in the boot of mmy and the costs to go that far cancell out saving

its the nitro that s the real cost killer as the engine fuel consumpion can be doubled or trippled if there is a high nitro content and the nitro cost ~ 8 times more than the cost of methanol. So engines that use no nitro or low nitro generally high compression are popular here

When I get my DF OS91vrdf late 2009 using ~3 onzes a minute on 20% nitro then my pips will squeek a bit but its still cheaper than Electric or gas turbine for the same size and speeds

I save locally about ~15% over the LHS prices mixxing my own on normal fuels of 10% nitro no castor but the oil levels are 18% which is too high for likeing . So mixxing my own returns control to me or doctoring a LHS batch to adjust the oil or nitro levels makes it interesting for me .

Most others who do small planes just buy ready made .heli guys and big engine guys mostly mix thier own as the bigger engines are mostly low nitro low oil content and dont like high oil content fuel from LHS the heli are high nitro so the bigger saving over ready made LHS fuel work for the heli guys

However a few dead beat heli guy buy in fuel from the USA and still cant grasp that becuase the USA fuel is a USA gallon about 80% a UK gallon they are actually paying more for the fuel eg they only get 5 gallons UK when it says 5 gallons USA they still think they got 5 gallons.Then they casnt grasp that ~30% nitro USA is only ~23% European measure as the USA fuels uses nitro % by weight and majority of the EU glow fuel uses % by volume so 30% USA fuel often isnt the same thing as most 30% european fuel types

The planet is full for dead beats who probaly deserve to get thier faces ripped

Balsaeater

mustangman177

Thanks for the replys.

Sounds like you can save 10-20 % possibly by making your own fuel, but the biggest gain in doing so is that you know what the actual % of your ingredients are.

I fly mostly smaller models .25-.90. size 2-stroke engines, Been loyal to buying Byron's fuel with good results. Last time was $20. gallon. Will see what the price is when I go back to the LHS (Not so local though) this spring to buy fuel again. I usually buy 12 gallons at a time, (due to location) which lasts me through fall. If the price goes up drastically, I will definitely look at making my own.

Once again, thanks for the input on this matter.

Cary

GhostRider32

I save about 50% mixing my own fuel. It's $22 tax included where I live to buy fuel and approx. $10 for me to mix my own with no nitro.

jetpack

My Feedback: (1)

You asked for it, you got it.

[link=http://www.nitrorc.com/default2.asp?Introduction=http://www.nitrorc.com/fuelws]Here is a link[/link] also that has a handy calculator for mixing percentages.



Glow Fuel Mixing

Recent nitromethane problems have resulted in limited availability of specific mixtures. You may want to do some fuel mixing or changing of existing mixes. Also, you may want to get some idea of what these fuels do in an engine. The following may help.

All mixes are described on a percentage by volume basis which seems to be standard in the glow engine fuel business. Standard American volume equivalents are:

1 U S gallon
4 quarts
128 fluid ounces
_____________
231 cubic inches

A typical mix, called 10% fuel, is 10% nitromethane, with 25% castor oil and 65% methanol- all by percentage volume so that a gallon of 10% looks like the tabulation below.

12.8 oz. nitromethane 10%
32.0 oz. castor oil 25%
83.2 oz. methanol 65%
______________________
128.0 oz. total (gallon) 100%

The calculation for oil, as an example, is 25% of a gallon which equals 0.25 x 128 oz. or 32 oz
and the calculation for nitromethane at 10% is 0.10 x 128 oz. or 12.8 oz.

The nitro and oil are carefully mixed with about half gallon of methanol and then the gallon is completed with methanol- thus avoiding directly measuring the methanol. Stir some more and cap the mixed fuel.

Mixed fuel, well capped, will last for years with no change in quality. I personally do two and a half gallons at a time. The materials discussed in this paper are methanol, nitromethane and castor oil. Alternates or options, such as nitroethane and synthetic oils, will be discussed briefly.

More exotic and dangerous materials should not be used. Methanol (wood alcohol, methyl alcohol, and meths in the UK) is the first oxidation product of methane, CH4, and has the chemical name CH3OH. Further oxidation produces formaldehyde, then formic acid, and finally carbon dioxide and water (CO2 & H2O), which is ultimateyou cannot burn water!

All of these godies occur in your engine and produce heat which does the work. Methanol is a colorless and almost oderless liquid which is a violent poison and is highly flameable. It burns with a pale blue flame which is not visible in daylight.
You could be on fire with methanol and nobody could see the flames.

Methanol produces 55,550 net BTU per gallon, a 3450 OF flame temperature in air, has a near 43 OF flash point (does not evaporate below 43 OF), and a 725 OF ignition temperature.

The addition of castor oil and nitromethane will slightly lower the ignition temperature of the mix. 1300 OF to 1500 OF temperature is indicated by the "color" of a hot glow plug coil. The flammable limits of methanol (% vapor in air by volume) are 6.7% lower and 36.0% upper.

So if lean or rich on a cold day (43 0F flash point), your engine will be a real bear to start. A gallon of methanol requires about 560 standard cubic feet of air for combustion, resulting in exhaust gasses composed of 78.4 standard cubic feet of carbon dioxide (CO2), 156.9 cu ft of water (H2O) at 212 OF (vapor), and 445.5 standard cubic feet of nitrogen (N2).

The nitrogen comes from air, 21% oxygen (O2) and 78% nitrogen (N2), which must be pushed through the engine to provide oxygen for combustion of the fuel. Good methanol is both anhydrous (free of water), and hydroscopic (absorbs water from air and is soluable in water). It should never be exposed to humid air (most air is humid) for more than a few minutes.

Dry methanol is a good fuel, while wet methanol is a dog- will still burn, but not well. Good dry methanol has a gravity of 0.7914 and anything higher shows water. Pure water has a gravity of 1.0000.

Castor oil is the "classsic" oil for glow fuel; a vegitable oil from the beans of a plant called RICINUS COMMUNIS. Chemically it is C11H10O10, viscous, clear to yellow, and about the same weight as water. Medically it was an old fashioned laxitive and if 75 year old memory serves was pretty potent!

Castor oil as a lubricant is exceptional because of heat resistance, cling, and lubricity. The cooeficient of frictiom for steel om steel, using castor oil as lubricant is 0.095, which is better than all other oils listed in the handbooks.
Compare to wet ice on wet ice with a cooefficient of friction of 0.05 to 0.15, where the lower number is the most slippery. Castor oil at 10% would lubricate an engine, but it is raised to 25% so that the oil can also act as a coolant. It does not enter into combustion, just pumps through the engine the same as nitrogen.

The castor "smoke" you see in the air is mostly fine droplets of oil. Traces of true smoke may be produced in a very hot engine. Castor oil smoke has a pleasant odor, while most of the synthetic oils have a perfume-like odor associated with their smoke. The two together produce a definite and unique flying-field odor.

The main difficulty of the synthetic oils is that there are so many of them, each manufactured for a specific purpose, but not for glow engines. I tried one by NATIONAL CARBON, which was manufactured as a substitute for castor oil, and used as a lubricant for rubber conveyor belts.

Using 1/3 synthetic and 2/3 castor as a 25% fuel component, I have experienced no problems and will continue as long as the keg of synthetic oil lasts. The big negative with castor is that it polymerizes to a tacky varnish when left on surfaces and exposed to air- makes messy airplanes.

Synthetic oils seem to reduce or soften this polymerization when mixed with castor oil. Nitromethane (CH3NO2) is a colorless liquid, sweet smelling, soluable in methanol, and normally stable- but with the chemical potential to detonate. When mixed in methanol it gives the mixture the "alcohol" smell and provides some oxygen for combustion beyond the induced air.

The OSHA exposure limit is 100 ppm over an eight hour period, so don't just sit there and sniff the stuff. At my purchasing level nitro is about $30.00 per gallon. The "old hands" say that the nitromethane "activates" the methanol, but as a nasty old combustion engineer, I do not know "what the watermelon hell", "activates" means.

Let's look at the combustion to see if we can figure it out. The molecular balance for the combustion of methanol (CH3OH) is: 2(CH3OH) + 3O2 > 2CO2 + 4H2O or two mols of methanol require 3 mols of molecular oxygen (two volumes of molecular methanol vapor require 3 volumes of molecular oxygen for complete combustion), but oxygen comes in a package called air which is 21% molecular oxygen and 78% molecular nitrogen.

There is 3.76 times as much N2 as O2 in air. 3O2 + (3.76 x 3N2) or 14.26 "mols air" are required to burn 2 mols of methanol. Fuel/air ratio for methanol is 1/7.14. The molecular balance for the combustion of nitromethane, (CH3NO2) is: 4(CH3NO2) + 3O2 > 4CO2 + 6H2O + 2N2.

4 volumes of nitromethane vapor require 3 volumes of molecular oxygen for complete combustion, which is 14.28 volumes of air as above. The fuel/air ratio for nitromethane is 1/3.57. Nitroethane (C2H3NO2) will provide available oxygen the same as nitromethane, but will not provide as much extra oxygen per unit volume.

Compare methanol fuel/air ratio with nitromethane fuel/air ratio, 1/7.14 for methanol and 1/3.57 for nitromethane. The nitromethane is providing some oxygen for combustion and needs less induced air to burn; in fact, twice as much output is available from pure nitromethane as from pure methanol for the same amount of air. So the nitro is a chemical form of super-charging.

With an increase in hp there is a corresponding increase in rpm, with an additional increase in induced (carbuerator) air, with a compound increase in output hp. I am working on an algorithum to relate % nitro to % increase in engine output realizing that no two of these little engines are the same or will experience the same operating conditions.

How much output increase is very difficult to calculate, but we know with increase in % nitro we gain in output, engine operating temperature, and the cost of the fuel. The conclusion is that nitromethane provides extra oxygen above that provided by combustion air and therefor improves hp output.

The practical rule is to provide no more nitromethane than needed for your plane, your engine, and your flying wants. Most of us can get along on 5% or 10% nitromethane fuel. 10% nitro is actually 13.3% nitro if you look only at combustibles- the oils do not enter into combustion so can be thrown out of the calculation for effective percent of nitro.

A twenty year old ringed SUPER TIGRE "60" size engine running at 11500 rpm pumps 6900 cu in of air per minute or 3.99 cu ft of air per minute- on a good day! Round this out to 3,5 cu ft of air per minute because of nominally poor air, porting losses and blow-by. Apply the old combustion rule that a cu ft of air can burn a 100 btu, and the old engine burns about 350 btu per minutr. The engine may "suck up" a lot more fuel than this, but wastes it; these engines are rich even when "leaned out".

1 1/8 oz of 0-25-75 fuel runs about one minute in the "60", but this is only 0.844 oz combustibles since the oil is not to be burned or about 366 btu of methanol per minute. Note that there is more btu of fuel than btu of combustion air (366 to 359), so the air is limiting the input of the engine to 350 btu per minute. 350 btu per minute is roughly equivament to several hp, but a lot of energy is lost to exhaust temperature and very low efficiency in these small engines.

The result is that engine output is estimated to be less than 3/4 hp- would hardly pull a sick river-boat gambler out of church! Your engine output may be more or less when running on 0% nitro. Back to mixing fuels. If we have a gallon of 10% and wish to chaange it to 5%, we first realize that the 10% has 12.8 oz nitro per gallon and we need only 6.4 oz per gall for 5%.

There is no way to take nitro "out" of the 110% gallon, so the 10% gallon must be diluted to reduce the nitro to 5%. The extra nitro can build another gallon of mixture at 5%. The second gallon requires 32 oz (25%) of oil.
Using a two gallon container, dump in the gallon of 10% mixture, add the 32 oz of oil, and enough methanol to complete the 2 gallons. Stir well and tightly cap the new 5% fuel. The new 2 gallons of 5% mixture is:

12.8 oz nitromethane 5% of 256 oz (2 gal)
64.0 oz oil 25% of 256 oz
179.2 oz methanol 70% of 256 oz
________________________________
256.0 oz total 100% of 256 oz (2 gal)

When the added methanol completed the two gallons, 6.4 oz of the added methanol filled in for the 6.4 oz nitro that was "taken out" of the 10% gallon to start the new 5% gallon. To move from 5% fuel to 10% fuel, start with the 5% gallon which holds 6.4 oz nitro. Now add enough nitro to make a 10% mixtue (larger container now needed).

The new mixture will have a volume of 128 oz plus whatever nitro is required to make a 10% mix. This sets up a small algerbra problem algerbra at the RC field what is this world comming to? If "x" is the added nitro, then (128 oz + "x" oz)(0.10) = "x" oz + 8.4 oz. This equation translates to 10% of the new volume is equal old nitro plus the added nitro.

Now you hot shot math purists realize that adding nitro requires that we add a little more oil and a little more methanol. We are approaching a true 10% mix by simultaneously adding oil and methanol. The above algebraic approxamation puts us within 2% of being "right on", so do not worry about it unless you enjoy simultaneous equations.

Presume a 5% mixture and a 10% mixture; the challange being to produce a 10% mixture. I would not waste my time thinking about this one- the practical approach is to correct the 5% to 10% and the 20% to 10% and throw the two into a container marked 10%.

References are the North American Mfg Co combustion engineering book and Chemical Rubber Co chemistry and physics handbook.



Here are also some safe guidelines suggested by Webra, who make no/low nitro motors and world reknown for some of the best engines available, and last practially forever using their mix.

Flyboy Dave

My Feedback: (21)

....yep.

mustangman177

Wow !!! Talk about the "Holy Grail" for brewing fuel. Very informative. Thanks.

Cary

hvymetalalchmst

hm... i understood all of it, but thats only because i have a kind of fascination that you share jetpack

but for some reason, and dont ask why, but i think that you may have gone a little overboard and overkilled what mustangman was asking for, haha

nonetheless, great info and very informative. im sure we'll all understand what youre saying by the time we're all 75yo combustion engineers too! :P

jetpack

My Feedback: (1)

Aaaah. The magic of "cut and paste" of gleened articles off of the internet can make even me look like a total genious![sm=lol.gif]

Beware of anyone with a full arsenal of glow power information stored on their PC. [sm=49_49.gif]

I think the article (I forget where I actually swiped that one!) is great, but I find the simple mixture calculator on that one link I put up is the best.

Luna_Rendezvous

The biggest problem with home brew fuel is finding suppliers of quality ingredients, the last lot of methanol I bought was utter s*#* Obviously the shop where I bought it from didn't use any filtering to stop moisture being introduced as they decant. Methanol is very hydroscopic, meaning it will readily absorb moisture from the air. Ask your supplier if they use a Vent Dryer of some sort, if they look at you funny and say what? Just turn around and walk out the door. If you intend to buy methanol in 5 gallon containers or more and you live in a high humidity area, then by yourself a vent drier and some reusable desiccant. If you mix a gallon at a time it ensures that the last gallon will be just as good as the first.

downunder

Well here's a bit more to add to the arsenal, nope, not a cut and paste this time but just something I've learned. Infernal combustion engines get more efficient the higher the compression is but of course this is limited by what the fuel can handle. Nitro is terrible at handling compression so you give away efficiency but gain back by burning a lot of what's really not a good fuel in itself.

Most engines have a compression of around 9-10:1 which is fine for relatively high levels of nitro (~20% area?) but methanol can handle around 17:1 compression. I experimented with an Enya 60X by running it on 80/20 fuel and incrementally raising it's compression. At 13.5:1 it'd gained a little over an extra 20% HP which probably put it somewhere around what it would get using lots of nitro. I'm certain I could have gone even further if I'd also experimented with colder plugs which would have retarded the ignition point so allowing an even higher compression to advance the ignition point again.

Given what I found, I convinced my son to use the same fuel in his car but with the compression also raised to the same level. It performed exactly the same as identical cars/engines using 25% nitro other than he could race for 8 minutes per tank compared to 6 minutes for the others. Quite handy when they have to make pit stops .

The difficult part about doing this though is you need some accurate measuring equipment and a lathe because taking out a few shims doesn't come anywhere near doing enough.

Ram Jet

Bite the bullet. Sig Manufacturing for fuel. Consistant quality, quality content, fast delivery, great customer service. If you have to ask how much it costs take up jig saw puzzels.

Bill

jetpack

My Feedback: (1)

He wants to mix, let him mix. There IS a cost savings. The answer isn't go buy a jug from Sig, and lump it.

Sig wants $12 for a gallon of FAI plus shipping charges.

How much does a gallon of methanol cost per gallon? I sure hope it isn't $12. He has a whole gallon of BeNol to use up.

Mustangman just needs to find a race shop that sells karts or speed parts for cars. A call to a local circle track would point him in the right direction. There seems to be at least one of either in most counties where I live.

Methanol can also be found in a bottle of HEET gas line anti-freeze, but you'll be buying a pint at a time that way...not too economical, but it is 100% methanol.

I buy from Sig, love the company, but when it comes to fuel it's not my first choice. I buy locally and mix myself and pocket the change.