I will start to conduct attempts to use mixxes including E85 / methanol on different smaller motor 15 to 46 and as well preferably on my MVVS 1.60 26cc 18*10 MA with 5% nitro 10% synthetic 85% methanol with tuned pipe when its more run in

The aircraft I use for MVVS 160 is a Biplane Ultimate 54inch for 90 2 stroke and is over powered so as to be able to do towing work so losing a bit of power isn't a big issue when not doing towing so cutting fuel costs helps

In reality manufacturer costs of methanol ~$0.80c (USA Gallon) are half the cost of Ethanol ~$1.60c (USA Gallon) but with the distribution systems and most world government tax warp this and the result is cost for Ethanol are artificially made half the costs of Methanol from the pumps or shops shelfs
Therefore its a no brainer to try to reduce costs using some replacement or all replacement of Methanol using cheaper Ethanol usually found in the form E85

Toxicity of all fuels Gasoline Ethanol and Methanol is really they are all equally toxic when compared to non toxic liquids like soda pop
as in they all penetrate the skin and accumulate in human organs to a lesser or greater extent , poison and foul taste the water but gasoline is probably the most toxic by a long way with Methanol and Ethanol being lesser toxic agents (and Methanol is not to be confused with MTBE a very toxic agent cousin derivative chemical of Methanol that replaced methanol for anti knock in gasoline fuels )

Explosive issues is gasoline is the most explosive of these fuels due to its low vaporization abilities but possibly mixing of these fuels can aid or retard these issues but suspect its not such a big issue
What appearantly can definitely risk to cause a big explosion is starting with mixing gasoline into nitro methane as that will become very shock sensitive at something like above 20% ratios eg 70% gasoline 30% nitro methane
Mixing the other fuels first and than finally mixing in nitro methane solves that issue

It appears most glow motors are tolerant of 10% gasoline mixed in and 10% gasoline often means 20% extension in motor ruin times
Other users using 60% E85 40% glow fuel 10% nitro 15%% synthetic = fuel mix of approx
~% 11 synthetic
~5% nitro
~9%gasoline
43% Ethanol
~37% Methanol
in a E85/Methanol mix which should reduce cost of fuel to ~25% to 50% and give hopefully more than 30% longer run times for same tank hopefully 60%

The power losses I expect to be more like ~5% instead of ~10% from total change over to E85


Experiments hopefully begin in April

Balsaeater

repeat post

Hate it when that double post thingy happens. I messed around with E85 a few months back in my SuperTigre's and found it to run quite well. Yes, I did have to run a different glow plug, specifically an OS A3 to replace an OS #8. After the plug change it idled just as good as 10% glow fuel. I then added 10% NitroMethane to my brew to try and get my power back which worked. All in all, it turned out to be a very good fuel. I have since converted it to Gasoline/Spark ignition with good results and that's what I am currently running it on.

Downunder, I have run automotive engines on ethanol with the C/R as high as 13:1 with no hint of detonation at all. Can't say how it would react with the C/R that high in a model two stroke as there are other factors involved such as the oil dilution which in theory should reduce the antiknock qualities of the fuel. That's just speculation though as I haven't tried raising the C/R on a glow and then running E85 in it.

Thanks good info

I have no ideas on C/R limits for Ethanol

My issues in Europe is typical local model fuel cost in components

methanol neat ~$16.00 gal imp ~$13.00 a USA gal
EDL and Klotz ~$100.00 gal imp ~$ 85.00 a USA gal
Castor Recin ~$ 46.00 gal imp ~$ 40.00 a USA gal
Nitro methane ~$140.00 gal imp ~$ 120.00 a USA gal

automobile E85~$7.00 Gal Imp ~ $6.00 a USA gal
automobile GAS~$7.50 Gal Imp ~ $6.50 a USA gal (5% ethanol)

cost for home brew 10%EDL 5% nitro 85% methanol ~$35 a gal imp ~ $30 a USA gal

I don't like to use any Castor and often using EDL or Kloz and I will use half the the amount of same in Castor so that is similar price and more power results from fuel with lowwer oil content but don't tune lean as that might grill motor



(info below supplied is for those confused why bother with these experiments and modeled in SIMPLEX )

From this the lowest costs for me in expensive Europe is a real no brainer
and is to convert to gas spark ignition if the oil content drops to ~3% and use no nitro


But this drops the power typically ~25% compared to methanol zero nitro mix (often even more as the fins for cooling need to be bigger so weight increase issues kick in )

Also pure gasoline motor will risk to stink out my tiny hatch back Japanese car and so does pure E85
and is a issue for traveling with smelly model plane in commercial flights

So after landing and quickly running engine with pure glow fuel will stop most of these problems

The most powerful and costly will be methanol with high nitro~30% plus with tuned pipes and highest compression ratios and cost can be ~5 times more than gasoline version but maybe exceeding ~50% or even more than 100% more powerful than gasoline versions

Mostly because gasoline is less powerful fuel than Methanol or Ethanol and gasoline uses less compression ratio
(Higher compression ratios often results in increased power)

ball park compression ratios C/R average for model motors

gasoline....6:1 to 9:1 ......average......8:1
methanol...8:1 to 14:1.....average...9.5:1 Example often OS tend to be a good bit lower than European low nitro S/Tiger or MVVS
Ethanol......7:1 to 13:1.....average.....9:1 (estimated from real aircraft using Ethanol)

sample reduced table of fuels might explain thing slightly better

source
http://en.wikipedia.org/wiki/Stoichiometry
http://en.wikipedia.org/wiki/Nitromethane

Fuel .....By weight ... Percent fuel by weight

Gasoline....14.7 : 1 .......................6.8%

Ethanol...........9 : 1.......................11.1% ~1.8 times more than gasoline

Methanol......6.4 : 1.......................15.6% ~2.2 times more than gasoline

Nitro.............1.7:1..(ball park est) 58.8% ~ 9 times more than gasoline


Source
http://en.wikipedia.org/wiki/Gasoline
http://en.wikipedia.org/wiki/Nitromethane

Injecting the above table into MJ/litre we see roughly how much power is available from other fuels in MJ/litre gasoline equivalent

nitro methane ~10.5 MJ/litre
(ratio consumption ~9 times gasoline result in a theoretical result of ~ 90 MJ/litre gasoline equivalent
(~ 3 times more power heat gasoline but this often translates to slightly less than double the power increase over gasoline )

Methanol 17.9 MJ/litre

usually a tad more than double the fuel compared to gasoline is used so real results ~ 70 MJ/litre gasoline equivalent
(~ 2 times more power heat than gasoline but this often translates to slightly less than 30% the power increase over gasoline )

Ethanol 23.5 MJ/litre usually a tad less than double the fuel compared to gasoline is used so real results ~ 60 MJ/litre equivalent
(~ less than times more power heat than gasoline but this often translates to slightly less than 20% the power increase over gasoline )

leaded gas 33.5 MJ/litre (estimate from leaded aviation gasoline and comparing to unleaded 5% Ethanol types of gasolines )

Uses the least fuel but less power and gets all oxygen from the air but also lower compression from knock issues

Adding ~5% Ethanol will aid compared to pure gasoline without lead additives to suppress knock but result in ~10% fuel increase and possible ~5% increase in power


Putting a tuned pipe on can retrieve ~5% extra power form most all types of fuels

Nitro methane Stoichiometric ~2:1 gets used up at ~4.5 times faster than Methanol Stoichiometric ~7:1
and ~9 times faster than gasoline ~ Stoichiometric 15:1

As nitro methane costs typically ~10 times gasoline this makes nitro some ~100 times more expensive to use than gasoline
or 50 times more costly than methanol solutions

so some rough ball park conclusions

This might infer using a zero nitro methanol fuel might be cheaper than using a 10% nitro with E85 fuel and return similar power
assuming same oil content typically 18% (50% synthetic 50% Castor) and is likely to be the case with lower compression motors like OS

Increasing the compression ratio and decreasing the oil content to 10% (100% synthetic ) and using 90% Methanol and 0% nitro and motor like super Tigre & MVVS which can do this will then probably produce more power than equivalent lower compression OS using 10% nitro with Methanol or Ethanol and be cheaper than both as the OS which usually require 15% to 18% oil

However for the novice the lower compression motors tend to be easier to start and tune and less prone to dead sticks especially the higher the nitro contents so its swings and roundabouts

In a WOT (wide open throttle ) given a choice between changing from motor 60 example simplex ~ 1 BHP with zero nitro WOT 1/4onz per minute
to use it with with high nitro like ~30% nitro to get ~1.5bhp 1/2onz per minute
or zero nitro motor like 90 to get same 1.5 BHP at ~onz per minute 1/3
the resulting fuel consumption from the 90 version will probably be ~50% a zero nitro version 60 motor
possibly supply 50% more the power 1.5BHP compared to a 60 high nitro version.
However the 60 high nitro version will probably be double the fuel consumption rate 1/2 onz per minute of the 60 motor using zero nitro 1/4 onz per minute
and will probably supply the same 50% power increase but do so on smaller lighter motor than a 90 solution
but WOT expect fuel costs to be quadruple due to high nitro factoring in multiplier affect on fuel cost

In the same scenario above for flying in acro or 3D the case is more confused
In hover with zero nitro 60 motor might be at ~1/2 gas position could be replaced with ~1/3 gas position for high nitro fuel or larger 90 motor and so fuel consumption wont be so much more excessive than zero nitro fuel when in hover mode and possibly fuel cost only ~50% greater cost with high nitro in hover mode and mayby only ~10% more fuel consumption from 90 zero nitro position

If the majority of the flight can be done at 1/3 gas with higher nitro 60 motor the cost impact is less bad the plane will tend to be lighter (but factor in fuel tank will tend to be 50% bigger to supply same flying time ) and have better punch out from hover and more grunt in the mid regime and more easier to tune (wide band tuning as in tuning will often stay the same all day long )

If cost is more important the zero nitro 90 version will be similar as higher nitro 60 version and have reasonable grunt at 1/3 to 1/2 regime as the motor will be less less stressed but will be a tad heavier than 60 high nitro equivalent but a tad more fiddly to tune (narrow band as in tuning cool early morning can be different to hot midday conditions )
The results will be similar in weight RPM and prop size and power to a medium nitro 4 stoke ~70 to ~75 motor

Heli 3D competition copters will tend to have no real choice except 30% nitro but planes can have extra options as wings can support extra weight better than rotor blades can

Replacing the fuel components with cheaper gasoline or Ethanol will impact slightly on power with gasoline affecting power the most
However the gasoline can allow less oil content as low as 2% and when its a component of fuel help lubricate motor so redducing oil lubrication needs compared to dryer Methanol Ethanol fuels
This can result getting some power back compared to 18% oil in pure glow versions
Also fuel consumption will be less with E85 type fuels so smaller lighter tanks can also assist power to weight ratios
Tuned pipes can also return back power but increase weight slightly and tend to be tuned correctly for one narrow rpm range which can be an issue for 3D
Pure Gasoline and E85 or Ethanol or high ratio mixed into glow fuels also nearly always increase weight with continuous drive glow battery or for pure gasoline a spark ignition solution adds weight also

Factoring in all these multiple of variables for me requiring a quazi four stroke large prop turning more slowly affect I can sorta achieve that with a standard two stroke when I double the size the of 2 stroke engine and run it at lower gas regime
Fuel consumption can also be controlled better with slower regime and bigger props turning prop more slowly in RPM tend to return better efficiency than smaller props at high RPM speeds

Bigger engines with low nitro rates will be more stable in engine regime at low RPM and will be possibly less affected with lower power fuel like E85 mixed into the glow fuel and tuned pipe could help recoup the lost power hopefully at ratios of 60% E85

With this formula my 90 sized biplane Ultimate with a MVVS 160 with tuned pipe costing ~$2.50 a 16 onz tank using 5% nitro 10% EDL and 85% Methanol WOT ~1.3 onz per minute mid regime ~3/4 onz per minute could possibly be replaced with a 60% E85 40% zero nitro glow fuel where elements will hopefully be

..8.00 % gasoline
47.50 % Ethanol
37.50 % Methanol
..6.00 % EDL or Kloz

And hopefully reduce cost of fuel to $1.60 c per 16 onz tank and probably still 3/4 onz per minute to get same power at slightly higher gas setting and recoup the lost 10% power with the tuned pipe and higher gas setting
and hopefully reduce costs per tank to
~60% of pure glow 5% nitro version
and suffer at most a 10% power drop compared to pure nitro version

For towing gliders work changing the glow plug and back to 5% glow fuel will give me max power

Changing to pure gasoline on these smaller motors is probably not worth the power drop and the possible risks of the greater vibrations and when I go on holidays on commercial aircraft simply changing the plane to run on glow fuel before departing can remove the serious strong odour problems with the gasoline and E85 fuels and allow me to more easily package the plane for international flights and simply buy the local glow fuels with 5% nitro preferably synthetic but Castor or mixed would do while on holidays


If the experiments fail well the MVVS 160 motor on glow fuel 5% or zero nitro is still affordable as its mostly on 1/3 gas or less to loop and most acro so its not to expensive each flight certainly with low nitro is probably cheaper than Lipo electric versions and probably a lot cheaper than 90 version on 30% nitro



I am also trying to work on a more complex version of this type of program supplied fre at this site


http://www.taa.org.au/html/home_brew.html

For standard glow mix this program works well and can I gather also supply costs per Gal /Litre /KG/LBS as you go along

I would want to try to more fuels including other families of nitro such as nitro ethanes also acetones and ISO alcohols etc and include Stoichiometric rates costs ratios and MJ/litre and so be better able to project better the cost and power ratio issues

If the program already exists or useful info is there be happy to look it up save me leg work

or if somebody with better programing abilities wants to do similar let me know also

Balsaeater

I experimented with an Enya 60X using 80/20 all castor fuel and gradually raised the compression from the standard 9.75:1 checking the rev increase each time. Past 13.5:1 there was no more rev increase so I backed off to the 13.5 as the final optimum compression. I kept the same plug during all this but further increase was likely if I'd gone to a colder plug. However this gave me a 22% increase in HP based on the before and after revs. With ethanol you'd have to do a similar experiment to find the optimum compression.

Excellent info and a lot cheaper than 10% nitro to get the same results

downunder you seem to be really up to speed with all the guru of this no nitro solutions so please keep the info flowing

Thanks

How was starting and tuning with the higher C/R?? or if there were issues as C/R increased did they kick in incrementally or did they arrive abruptly at certain C/R like 12 :1 or similar or were there no issues ??

Using the same methods this might return back sufficient lost power using E85 or Ethanol to make it more interesting to do !

I have a very rarely used pre 1990 Super Tiger 4cc 25 that needs experimenting on as it seems only to know one speed WOT
and its cheaper than experimenting first on my bigger engines which eat fuel fast

To raise the C/R do you machine down the head or do you do it buy hand carefully as I don't have access to Lathe or similar and can only remove shims or do manual changes


Later if experiments pan out well instead to get new MVVS 45cc gasoline version I could get the Glow version and make a FLEXY FUEL version before putting it into a 1800mm CAP and hopefully get power outputs like a 80cc gasser

Balsaeater

Brian, you may have already answered this in another thread and if so forgive me for asking again. Are you measuring C/R for the full piston travel or just from where the ports close?

Jezmo,
I prefer to measure compressions using swept volume same as used for 4 stroke car engines, mainly because even a 4 stroke has it's inlet valve still open past BDC (gas inertia..blah blah blah). It's a bit of a controversial subject as to which way is more correct but because 2 strokes all have very similar timings then either way can be used. I just find it simpler using swept volume because I'll have already measured the stroke or found it in the manual.

With the Enya, starting was identical (one flick, can't improve on that ) but you can feel the difference in compression although it was still quite easy to flick over. From memory (a hard disc crash wiped out all the details) I increased it each run by .5 at a time until the rev curve started to flatten out then went by .25 for the last couple of runs. There was no difference in handling on any run. As far as tune goes, the main needle needed to be about a quarter turn further open but the idle surprised me because I had to lean it out considerably (the Enya uses an air bleed for idle but also has a midrange adjustment). Idling was much smoother and lower, I suspect because it had much more useable idle compression which made it more efficient at burning fuel. In flight it gave one more surprise in that it unloaded like crazy , far more than it did before. It's never burned out a plug and got quite a lot of flight time after the testing (which really didn't take all that long anyway). For interest's sake, the modded .60 exactly matched a standard Enya .80X on the same prop and fuel.

I had to machine the head to raise the comp to the level I needed because taking out any shims simply doesn't do much at all. As I said, I lost my data but I'm fairly certain I ended up lowering the head by .024", most shims are only about .008" and usually only one is fitted anyway. On the Enya, removing this much was no problem because it still had around .020" squish clearance. I've got a self imposed limit (meaning hey let's not take any chances here ) of .010" squish clearance.

Engines will vary as to how they respond though. I did a quick and dirty mod to an ST 45 not long ago and only saw a 200 rev increase which worked out to about 4% extra HP but I was basing the before revs on a run I did long ago, not back to back. My son bumped up the comp on his SC 1.08 and got a massive 800 rev rise. This was the same increase I had with the Enya but his engine was only turning the prop down around the 8500 range where the Enya was in the 12,000 range.

Thanks
I know a machinist and can throw him a few beers XXXX now I know the principle

Pity my RC Enya 2.5cc 15 died from a crash but thats life

Balsaeater

Brian,
Thanks for the info. I am in the process of raising the C/R on my SuperTigre 51 that I am running on gasoline with spark ignition. I have it at 11:1 now (measured by the swept method) and the power increase is huge over the stock C/R. Yes, as you said, just taking out the head shim isn't much so, like you, I have been machining to get the rest. I am running high octane race gas so I should be able to go to at least 12:1 without fear of detonation. After I get the needle bearing rod in it I am going to try some E85 and see how it runs on that. Have a great one in the land downunder.

I have a question about oils. I have been reading about home mixing fuels and was curious about mixing lawn type 2 stroke oils with E85 to attempt use in glow engines. I know caster and its synthetic counterparts are supposedly superior oils for glow motors, but the primary reason that has been given for its use is the lack of anything else blending with methanol. If lawnmower 2 stroke oil will blend with 100% gasoline, it should at least stay mixed with E85. I may be way off in thinking this may be a way to get away from expensive castor and synthetic castor, but it would be nice. Anyone have any thoughts or experiance with this brew?

Ethanol is a alcohol like Methanol and 15% the E85 is gasoline
I ant no expert but the last links I saw suggested that alcohols are different in molecular bonding and resist disolving the normal gasoline lubrication oils and so might suggest the oil will fall out of suspension to easily
The gasoline fuel has a exrra lubrication quality and hopefully could help reduce amounts of lubrication needed

I personally haven't experience of mixing E85 as it only came my local region a few weeks ago but if somebody does speak up and hopefully save me money from experiments that wont work

Balasaeater

I have been doing more tests with E85 fuel and have some info that you might make use of. I bought a remote temperature meter from Harbor frieght on sale, with a laser pointer. I measured the cylinder head temperature of several engines in the .25 to .61 size range in cold weather (30 degrees to 50 degrees F). Engine manufacturers don't seem to give that info out. Engines running on 15% nitro commercial fuel seem to run between 350 and 400 degrees F. E85 runs at about 220-275 degrees F. (These of course are on the bench tests). I find that wrapping the cylinder head with thin cardboard to insulate it brings the temperature back up to 350 when using E85. This really helps improve the engine operation. Also after trying every glow plug I could get my hands on here in the out back, I have settled on the one that gives the best performance and life, at a reasonable cost (remember my goal is the cheapest flying possible). The Thunderbolt #115480 4 stroke and large 2 stroke glow plug is the best I have found. It runs very well on E85, with excellant power and has a long life from my tests to date. Note it is still winter here, so temperatures rarely go over 50 dregrees F, usually sub freezing. The OS F 4 stroke and other 4 stroke plugs are too fragile, and burn out after several flights. The cold plugs run, but the colder operating temperature retards the timing so output power is low under the cold conditions. Perhaps they will be better once summer arrives. The Thunderbolt plugs are available from Hobby People for $5.49.
I advise buying a remote sensing temperature meter frome Harbor Frieght or some other place, as it really helps figure out what is going on.
Once summer arrives, standard E85 will become available (85% ethanol, 15% gasoline). Hopefully it will work better than what I have now (70% ethanol, 30% gasoline, the winter blend available here).
My next step is to make some new cylinder heads that accept 2-3 glow plugs. I think that will boost the power. Only one plug has to have an intact coil, so I can use some of my sacrificed test plugs. I will make the heads with no cooling fins to increase the temperature up to 400 degrees F. I will make a baffle to install for winter flying as well. I would like to make an automatic temperature regulator baffle system using a servo and a small microprocessor controller, but it would be a bit heavy and only practical for larger engines. I will post any new test results that I find.

Good luck

Re: sopwith

Once summer arrives, standard E85 will become available (85% ethanol, 15% gasoline). Hopefully it will work better than what I have now (70% ethanol, 30% gasoline, the winter blend available here).

I would think that winter blend with more gasoline will be hotter as gasoline burns very hot

the low temperature is not sounding good

I can handle higher costs so running a 50% glo and 50% e85 soulution would be ok for me

thanks keep us posted

Hi sopwith, most valuable info you share with us above. I sure admire your systematic approach to the use of E85 and you certainly changed my earlier misconception about engines running (too) hot on E85....THANK YOU........I will try E85 again this coming season and make sure the engine(s) become hot enough to run well. Do not know what could be a european equivalent to the Thunderbolt plug you used..?..any ideas..? I will try E85 on my 4S Saito engines as before...Cheers/Harald

I have tried lots of plugs, but getting European plugs is a problem here. I know a fair amount about 2 stroke plugs, but don't have a clue about the 4 strokes, what heat range they are, how much platinum they have, exactly how they retain their heat from cycle to cycle, ect. All the 4 stroke plugs I have tried run well on E85 (except the Fox brand, which runs poorly). The big problem is that they all die fast when used in a 2 stroke engine. I guess they can't handle the extra power, the coil breaks after a few flights. The Thundebolt plug I mentioned is the only one I have tried that does not burn out after multiple flights. It is advertised as a "4 stroke and 91+ 2 stroke plug", so I would look for a European plug that has a similar description.
Wrapping the head with an insulator is important as well. Measuring the temperature I see that the engine will not run reliably until the head is at least in the high 200's F, and the plug heater has to be kept on much longer than with methanol fuel as well, adding further stress to the plug. Starting the engine is difficult in temperatures below 50 degrees F. I squirt a little pure methanol into the carburetor for starting to solve the problem. Once the engine is heated up, it runs fine, I don't have any dead sticks anymore, and the needle valve sensitivity is much less when the engine is a stable high temperature. I highly recommend getting an infra red remote thermometer to figure out how big a baffle you need on your particular engine cylinder head.

Good luck!

thanks

excelent info keep it coming

My understanding is that with less oxygen on the molecule for ethanol and no oxygen the gasoline molecule the less fuel input and beter ranges obtained compared to Methanol fuels would reduce cooling from as less fuel is put into engine to soak up heat

Also the platinum reacts best with methanol and less better with ethanol and often requires a permanent on board glow driver to react with gasoline fuels

I think also a measure of the RPM would indicate if there was a drop in power from possibly the gasoline not burning at all or the fuel is not burning completely and therefore reducing benefits to change fuels to a pure 100% E85 version

E85 mathematically should result in a 5% to 20% power drop over methanol fuels due to less calorific values with smaller engines showing the biggest power drops

But a lot of experiments being done in this time do not seem to match the predictions ??

every extra fuel solution all helps

balsaeateer

Came to think of the OS A3 plug which I believe should have a coil of somewhat thicker diameter than usual...and pretty cheap plug too...have you tried it..??....Cheers/Harald

There were some questions about my posts, so I will elaborate further. Before I tried E85, I was mixing my fuel with methanol with no nitro. I tried all kinds of mixures to see how they worked. I tried mixing gasoline and diesel in various percentages. They both caused very poor operation in all ambient temperatures. I was surprised about the gasoline problems, but I suspect it interferes with the catalytic effects of the methanol and platinum. The more I added, the worse it got until it would not run. Needle sensitivity got worse as well. I did not have an IR remote thermometer so can't comment on engine temperature. I did not take notes at that time, so don't remember what plugs I tried ( I since have wised up and write down everything I do). I abandoned the use of other fuel additives with the exception of acetone, which helps a bit in cold weather starting. When methanol prices rose to over $5 a gallon here I started experimenting with E85. I have never had access so far to summer E85 (85% ethanol, 15% gasoline). I have only used winter blend (pump sign says "may contain up to 30% gasoline"), so I don't know what the actual mix is. I am sure the gasoline is interfering with combustion as it did when I tried it with methanol, so I am hoping for better performance when I get my hands on the summer blend.
I tried lots of plugs, the OS A3 needs the glow heater attached for the engine to run. I tried Thunderball super cool plugs, the engine runs but it appears the timing is retarded as the engine power is low. Other cold plugs worked better, the best was the Duratrax Gold plug, but the element would burn out after a few flights. The OS R5 was not quite as good as the Gold plug, with the same burn out problem. All standard plugs will not run without the glow heater installed. 4 stroke plugs generally ran very well, except the Fox Miracle plug, which was not much better than a standard plug. They all burn out after a few flights except the Thunderbolt #115480 which is advertised as a 4 stroke and .91+ 2 stroke plug. This is the only plug that seems to run well and not burn out prematurely. I don't know much about 4 stroke plugs, can't seem to find a good site online. Some other posts say they have good luck with the OS A3 and other hot plugs. It may be engine dependent, as none of my engines run with it. Also my flight field (cow pasture) is at 5300 feet above sea level, and all my E85 tests have been in the winter with cold temperatures. The engines I have tried are older OS FP .25, OS FP .40, Vecco and K&B .61, newer OS LA .40, Super Tigre .45, Thunder Tiger .46 engines (several of each). They all have similar operation on E85, with the older engines running the best.

P.S. from my last post ( I always forget something). There were some questions about power loss with E85. Some posts claim there is only a few hundred RPM drop in power when compaired to commercial glow fuel or methanol without nitro. This is not my experience. Realistically you can expect a drop of at least 1000 RPM, and likely several 1000 RPM. This is a substantial power drop. To get a good idea of how much power you lose, download the free "extended prop" software and calculate the power loss from:

www.gylesaero.com

The software available at this website is among the most usefull I have encountered. Some programs are not free, but the prices are one step above free and top notch.

Good luck!

My local prices for 100% methanol are ~$15 USA gallon and been static for several years

My Gasoline and E85 prices are ~$ 6.50 a USA gallon

Most Europe would be simalr high prices due to tax so E85 is a very very interesting option

Ethanol would tend to run best at lower compression ratios (CR) than Methanol But higher compression ratios than Gasoline

Probably find the older engine are built for low CR with high nitro to bring CR back up

On a engine with 10,000 RPM with methanol a drop to 9000 RPM would often mean ~20% plus drop in power and not 10% due to the drag^4 affects on props


With the cost of motors being very low relative to fuel cost simply purchasing a motor with 25% to 50 % plus bigger size in CC or cubic inch would often still make this a very interesting fuel to use when Methanol cost exceeds $ 5 a USA gallon and at $15 a no brainer


Thanks for saving me experimentation with straight gasoline from your results

Its E85 or E85 glow mix of some sorts

thanks for the links

Balsaeater

I have been starting to buy older engines on Ebay that are larger than recommended for my planes, .40 for the .25 planes, .61 for the .40 ect. to make up for the reduced power of my home made fuels. It adds weight, but the lower fuel consumption allows less fuel per flight, so it sort of evens out. I only use synthetic oil at 10%, so that increases the power slightly as well. With the lower power output and cooler operating temperatures I have no fears of ruining engines. If I ever do destroy one with too little oil (I haven't done so yet), the saving in fuel costs makes up for the occational loss of an engine, witch are mostly used anyway. For a competative flyer, cheap fuel mixes don't make sense, but for the fun flyer it is the only way to go.

For those of you interested, I just bought a case (4 gallons) of Green Heavy 4 Stroke oil from Morgans Fuels. It cost $25.30 per gallon including shipping. That is cheaper than caster oil, and considerably better. I was surprised it was not more expensive. The phone number is:

334-347-3525

I have always bought my oil from these guys, its 54 bucks a case of 4 gallons.. plus shipping

I always used the light with castor, works fine for me...

They sometimes run a free shipping deal, wait for it stock up!!!!

http://www.tommyskarts.com/Cat.Oils.htm

Looks like Tommys Karts is the place to buy oil, cheaper than the manufacturer. It may be about the same after shipping though. It said $8.00 minimum or something to that effect. I assume that is per gallon. They also had the heavy without caster oil (case) for $66.24, still a great price. I only use the caster free stuff, since in winter the caster oil gums up the engine. Does anyone know of a place that sells the oil in the center of the country for those of us out here?

Thanks