Here is the data on Stoddard solvent: aka White Spirits or Paint Thinner, which maybe what is in some BBQ Lighter Fluids too.

http://en.wikipedia.org/wiki/White_spirit


Kelly

When biodiesel is made glycerin is a byproduct. In our case when making lubricant we are adding glycerin.

http://en.wikipedia.org/wiki/Biodiesel
http://en.wikipedia.org/wiki/Synthetic_oil

Biodiesel does improve the lubricity of blended fuels. It's more viscous compared to petrodiesel. If viscosity of the blend increases from 2cSt to 3cSt this is a big change. That is great news for a diesel pump which only needs 1.8cSt viscosity fuel to survive. That doesn't make it a good lubricant for friction bearings. Most B100 solidifies above 0C. Soy Gold says their fuel has a viscosity of a bit over 4cSt.

You have to careful reading crap on the internet. Everyone has an agenda. I do not believe anything until I've seen the same information in a university study or several different sources. Higher viscosity is great fromt he standpoint of lubrication. Injection varies with viscosity so it might not be good as spray patterns deteriorate with increased viscosity. But biodiesel is required to be within the specified range for diesel fuels. Straight vegetable oils are not.

Is mineral spirits cheap? The hardware store cost is ~10USD per gallon. Hardware store Kerosene is ~8.50, and Pump Kerosene is under 3USD around here. Kerosene has a significantly lower auto ignition temp so I'm not sure why we want to stray from kerosene. Properties of mineral spirits seem to be similar to No.2 Diesel.

Auto ignition temperature of napthas in lighter fluids seems high at 300+C. Flash and poiling points are low.

Naptha by the way is a very general term. Gasoline and kerosene are considered napthas.

You have to careful reading crap on the internet. Everyone has an agenda. I do not believe anything until I've seen the same information in a university study or several different sources. Higher viscosity is great fromt he standpoint of lubrication. Injection varies with viscosity so it might not be good as spray patterns deteriorate with increased viscosity. But biodiesel is required to be within the specified range for diesel fuels. Straight vegetable oils are not.

================================================== ================================================== ==============

Greg,

Agree with you there about the Internet. What I do is to make sure I read as much as I can, that's presented on any search engine. And it can be useful to use more than one search engine. The problem is retaining what you read.

Just now, I stumbled on this:

http://auto.howstuffworks.com/diesel.htm

Mesmerizing. And the article is quite informative.

Hi all,
Some great posts again. I am glad to see a bit of explanation about modified veggie oil. Please give us more info if you have it... me, I am a chemistry virgin []

Regarding the comments about the modified veggie oil being similar to biodiesel.....
When the oil is allowed to settle overnight, or longer ( I have some which was produced days ago) there is no seperation into different layers. All that happens is there will be a bit of "crud" on the bottom of the container. Once the oil is filtered off into a clean container then there is no further deposit of any sort.

When heating and stirring the oil it will be seen, late on in the process, that there is a very thin layer of deposit on the bottom of the pan. The washing up liquid I used is green in colour. Towards the end of the process the oil is yellowish and there is a seperate, small cloud of green in there. It stays seperate from the mix and eventually dissapears, I assumed it is some sort of colouring tha is applied to the washing up liquid and it gets thrown out as non-essential gunge by the process of modifying the oil.

When the modified veggie oil is mixed with paraffin (kerosene) then it stays mixed... there is no seperation of any sort. I have some in a clear container that was made days ago and looks just the same as when I made it. It has been subjected to widely varying temperatures in my shed, fairly hot during the day and a lot colder of a night.... unless we get down somewhere near freezing (heaven forbid for a few months yet) then temperature variation doesn't seem to have any effect.... very cold temps may not make any difference apart from increasing the viscousity of the mix a bit... time will tell [X(]

I don't think, from observation, that the modified veggie oil is acting as a fuel in anyway. The exhaust is VERY oily, but pretty clean. From the amount of oil being thrown out of the exhaust it doesn't seem likely that the veggie oil is burning in the engine.I cleaned my engines down after using the veggie oil fuel and checking them days later they are not "sticky" like when they have been used with castor lubrication. When using a power pod with normal castor based glow or diesel fuel it will be sticky to pick up even though the wood and the engine were well washed down after use.... the veggie oil doesn't seem to leave behind this sticky deposit.

I think the reason for the modified veggie oil and parrafin mix is the viscosity of the two combined, the fuel is thin enough to act exactly like the normal commercial ether mix and the compression and combustion process is very similar with either fuel. It only takes a 1/4 turn increase in compression to get good running with either a 10% ether mix or the full blown entirely etherless mix. A 1/4 turn increase is very little and is no doubt due to the slightly higher temperature needed for combustion of the paraffin. There is only a tiny difference in compression with 10% ether compared to no ether at all.If the engine is set up to run properly with a normal 30% ether and castor type mix then it is only 1/4 turn on the compression screw to run an entirely non-ether and veggie oil mix. The needle needs turning in about 1/2 turn from ether to non-ether.

I wonder...... 2 stroke oils will probably be a bit thicker than the modified veggie oil, does that increase in viscosity affect the compression and combustion cycle ?

It would be interesting if chevy tried his mix, using diesel oil and cetane booster with modified veggie oil instead of weed-wacker oil. Alternatively if he used kerosene instead of diesel oil he may find a difference. I would hazard a guess that the compression could be backed off (the 1/2 turn increase he is using sounds a lot) and the exhaust will be cleaner.

I also wonder....
If there is white smoke being thrown out with the diesel oil mix that chevy is trying... something is not burning correctly ? White smoke idicates incomplete combustion ???

Whe I set up my PAW 2.49 RC for best running conditions with the entirely etherless/veggie oil mix then there was just a light haze of blue colour coming from the exhaust... does this indicate much better combustion, the exhaust was still nice and oily so I wasn't cooking chips in there

I wonder if bio diesel is going to effect things the same way... viscosity too high ?

Didn't someone try BBQ starter or naptha and find it wouldn't run properly when mixed into the fuel they were trying ?

Like chevy I think it is great to finally run a model diesel engine on something close to normal diesel fuel. What sort of diesel uses ether ??? Nah, it's an abomination !

The weather is preventing any testing at the moment, I might just get chance to try another PAW tomorrow but won't get chance to fly the etherless mix until next week, assuming the weather will be better next week.

Reg

Andy and Greg

Thanks for the great link on How Stuff Works:

I clipped this bit out:

Diesel fuel has a higher energy density than gasoline. On average, 1 gallon (3.8 L) of diesel fuel contains approximately 155x106 joules (147,000 BTU), while 1 gallon of gasoline contains 132x106 joules (125,000 BTU). This, combined with the improved efficiency of diesel engines, explains why diesel engines get better mileage than equivalent gasoline engines.

Notice the term: “Energy Density�

I was using this concept in this thread about etherless fuel to illustrate the idea of lowering the ED of a fuel in hopes of matching the fuel metering system to a higher ED fuel. I do believe that Greg did not agree with the concept of energy density. I hope this clarifies this concept.

One more thing: I noticed this week an advertisement for a DDD head for the OS 1.60 engine. In the advertisement it showed and talked about a plastic venture reducer installed into the carb to make the required adjustments to the higher ED fuel. I do believe the mag was “RC Flyer�. The reducer looks like it made the intake about 30 percent smaller.

I do think this sort of reducer would be helpful to converted engine like the nice little Norvel .074

Have fun,

Kelly

I think that the white smoke is the incomplete burning of the lubricating oil. It might even be a bit blue-ish. My run times on a 4oz tank seem pretty good so I think I must have pretty good combustion.

My mix is pretty stinky and smoky and may not be acceptible for some people and places. I don't mind it though. Heck I like riding on steam trains burning coal with huge clowds of black smoke :-). A smoke trail comming off the airplane is just cool!

I just might try the vegy oil cook up soon. I have about 40 gallons out front from when I used to play with running my truck on the stuff.

Treven.

That sticky mess is what I want to eliminate. It runs great on castor etherless, no complaints, but the mess is bad. Synthetic is much cleaner and wipes right off the bench and engine days later, I haven't flown synthetic yet because I wrecked the model.

The modified veggie oil would be fine for me if I made a gallon at a time and used only 10-15% in the fuel. I'd be making oil only once a year or less. It would be worth the hassle if it's cheaper than synthetic and runs as clean in the engine. The only thing that worries me is viscosity. Unless we measure it, we don't know what it is. Straight corn oil is about 5% as viscous as 70W motor oil, and 10% the viscosity of castor. So what does it become after the process?

Blue/black smoke should indicate rich mixture but good combustion. In my estimate our engines are running very rich, quite a way to get to stoich ratios.

I understand energy density. Energy density is a useless term for aircraft as weight is far more important than volume. Fuel is sold by volume so this is important in that regard. That is the primary reason we are using kerosene over methanol. Hydrocarbon fuels in the range of gasoline diesel, and kerosene have, Specific Energy, in imperial units BTU/Lb, varies little. When they fuel an aircraft they talk in terms of pounds of fuel not gallons. Engine efficiency is specified in pounds per HP per hour. Kelly back in post 130 is where you talked about that. Fuel air ratios are specified in mass. Why? The density of air varies with altitude.

Fuel, g/cm^3, BTU/Lb, BTU,Gal
Regular gasoline, 0.735, 18630, 114200
Premium gasoline, 0.755, 18440, 116200
Jet fuel, 0.795, 18420, 122200
Diesel fuel, 0.850, 18330, 130000

The above is from Chevron's website.

How does the energy density come into play in our engines, or any engine for that matter? Energy density is just a characteristic of the fuel. It doesn't change the way it burns. You wanted to use fuel with a lower energy density, and I don't understand why that would be desireable. Your notes on oils in that post don't seem to make sense. The oils that claim to be the cleanest burning have the lowest flashpoints. I'll agree that carb's need to be adjusted for it, but I think we are talking about combustion.

Intersting note at the bottom of this page.
http://en.wikipedia.org/wiki/Detonation

I'ed just like to post a warning/explanation on oils.
For those trying new oils as lubricants in there motors, be aware that
if the motor is run in/ well used then the running clearances have
been astablished on whatever oil you were useing.

Why is this important?
Well when new a motor may not have sufficient clearance in all
moveing/rotating places that need lubrication, dureing "running in"
these places suffer high rates of wear untill the clearance is
sufficient for the oil in use to fit the gap. At this point the wear
rate drops to allmost zero- ie: its run in.
Now changeing the lubricant to higher or lower viscosity will effect
the required clearances for propper opperation, if the new oil is
similar in viscosity to that used in running in there will be no probs,
BUT if the new oil is higher in viscosity the running in process is
restarted to establish the correct fits for the new oil.
If the new oil is lower in viscosity the clearances may be too great
and the surfaces will suffer more wear due to hammering or cyclic
movement-ie the crank rolls around the brg instead of just rotateing
within it.So increased wear and shorter motor life may result.

Now if we find after short trials that the modded vegi oil has the
desired traits we are after in our fuel its use in a new motor ie-
running in on this oil and continued use should give as good a life
as with castor.
So be aware that any motor used for testing fuels/oils is probably
going to suffer accelerated wear from higher compression settings and or
changed oil viscosity, BUT a new motor on the new fuel/oil should give
a normal life span.
Stewart

I've been resistant to the concept of reducing the bore in the throttle of our converted engines because I've found that with glow, the manufacturer seems to err on the conservative side to make sure that ganging of tolerances are taken care of. It works and works well but being the power nut that I am, I typically bore out glow throttles for more of that magic and because I run muffler pressure, generally have no problems. If I run diesel, I leave the bore alone, (most times) and that can work too, most times.

With a 40% ether mix, I've had no problems on the .06 and .074 in the air. However, as we play with more exotic fuels, this may be a bigger consideration. Elsewhere on this thread or on YouTube, this has been contradicted in some cases.

With the wonderful little Norvel .074, if converting to diesel and you have concerns, you can swap in the .06 barrel. This has a smaller bore and is a drop in replacement. Thanks, Kelly, for bringing that up, I had forgotten and will be something to do as we fly our new strange brews.

Greg,

As per above, I think Kelly WAS referring to the changes usually required in carburetion when playing with differing fuels. Sometimes it's hard to express exactly what you mean on the first go around. When I did my first article in FM back in 97, it was my first experience doing such a thing. No literary genius I, Frank Fanelli was still pleased that all he had to change was a few commas here and there. I had to admit to him that the article took a year to write, off and on, as some of the work was done. The text in the article had been rewritten and revised many, many times, perhaps two or three dozen. Even now, as I read it, I mentally make changes realizing this or that had not been made entirely clear.

And maybe it's me but as I go back to some previous posts on this thread, I get new understandings of the issues that have come up as we go along. Ping and detonation was one.

Stewart,

That explains how I blew the rod in the .15 with the no oil, all biodiesel fuel. I've never seen a pin suffer such galling against softer aluminum. I suppose there might be a way of determining RELATIVE viscosity? As in, fill a small eye dropper and note the time it takes to empty with, say castor, and compare that to your other oils? Or do the same using a larger container for mixed fuel containing different ingredients.

"Diesel fuel has a higher energy density than gasoline. On average, 1 gallon (3.8 L) of diesel fuel contains approximately 155x106 joules (147,000 BTU), while 1 gallon of gasoline contains 132x106 joules (125,000 BTU). This, combined with the improved efficiency of diesel engines, explains why diesel engines get better mileage than equivalent gasoline engines."
Greg is right about the btu by weight, not by volumn.

The diesel engine is more fuel efficient is that it can convert more its btu to motion-energy than gasoline engine.(35% v. 15%). Therefore
the gasoline engine for the same HP should be hotter than the diesel engine since the btu of a gas engine went into heat instead of
motion energy.
If I understand correctly, the key for higher btu converted to motion energy between these two type of engines is its compression
ratio. "Higher compression is more efficient"

Ken

Ken,

Efficiency is a complex matter. Gasoline engines are more than 15% efficient. Recent Honda engines are ~33% if I remember correctly. The largest diesels in cargo ships are about 50% efficient. Compression does have an effect on efficiency but there is a point of reduced return. Injected diesels need 18:1 to allow cold starting. Spark ignition gasoline engines are limited to ~13:1 for the best designs due to fuel characteristics.

http://en.wikipedia.org/wiki/Specific_fuel_consumption
A Prius BSFC according to one link I found is 225g/kWh.

I estimate BSFC of my FS-48 conversion to be 360-380g/kWh on kerosene.

Andy, if Kelly was talking about the difference in carbs due to fuel, the real question is how much air does the fuel displace? With a 10% difference in volume comparing diesel and gasoline, this is trivial compared to methanol which requires twice as much volume and mass to equal gasoline. Since the density of methanol and kerosene are close we could say it's just the fuel air ratio. Straight methanol is 6.5:1 but I'm sure we run rich at ~5.5:1 and Kerosene should be 14.5:1, but I think we run rich near 11:1. We should be able to reduce the area of our carbs by 10% without ill effect. This doesn't consider the cooling effect of fuel evaporation. Restrictors in my opinion go back to the idea of mass flow reduction associated with the reduced RPM we run diesels at. The biggest change in carburetion is jetting changes(needle setting). Because we use needles instead of fixed jets this is a no brainer, the engine won't run unless the needle is close. The main thing is that you want o keep a certain velocity thru the venturi so that there is enough pressure differential to have good fuel draw.

I have tried restrictors in my four strokes and have not come to a definite conclusion at this point. So far I have just tried them but not evaluated the science behind it. The Enya 41-4CD has a substantial restrictor.

I was thinking the same about comparing viscosities to known lubricants. The probelm is keeping the lube at engine temperature to get a meaningful comparison.

Good day all,

I did some more reading (till my eyes glazed over and my brain siezed ). You convinced me that the process of cooking veggie oil as some have been using is not the same as making biodiesel.

I just rediscovered a forum that Andy already had about biodiesel stuff.

http://biodiesel.infopop.cc

I have posted some questions about our cooking veggie oil process with relation to biodiesel in the hope that someone in the know will provide a clearer understanding.

here : http://biodiesel.infopop.cc/eve/foru...1/m/5151043661

and here: http://biodiesel.infopop.cc/eve/foru...3/m/3361084661

for anyone cooking up a batch of veggie oil, common consensus from much reading of the above web site seems to indicate that Canola oil is the better choice with soya oil not quite as good; however the difference between better and not quite so good is very small and with all things gleaned from the internet, to be taken with a grain of salt.

This is an interesting site if you have any interest biodiesel / green fuels. Lots of rhetoric but lots of interesting tidbits as well.

In any respect, I took some time to continue my biodiesel testing yesteday before the rain started. In these tests I added 10% kerosene and 10% ether to the straight B20 biodiesel (20% biodiesel 80% mineral diesel). Assuming that the unburnt oil's that I have been seeing in previous tests is the biodiesel and has been acting as my lubricant, the addition of the kerosene and ether reduced my oil content from 20% to about 15 to 17%, still acceptable I belive - remember my test engine is a old nearly worn out PAW 2.49CC.

This mix ran well, better than the B20 biodiesel + 5 or 10% ether. Less messy, less oil coming out of the exhuast but still a white/light blue tinged exhaust. Notice that I did not use any Cetane Boost.

Next test was the same mix with the additon of 2.5% Cetane Boost (Amsoil brand). It did not run as well. Compression and needle valve setting where more sensitive and it did not run out the full tank of fuel before stopping on it's own.

I have never had a clear indication in any of my testing of what effect more or less Cetane Boost had until now. Clearly 2.5% Cetane Boost had a deterimental effect over the mix without. I have been using 2.5% as it seemed to be a good figure, common convention or wisdom was always to add ignition improver at about that percentage. From now on I think I will less, 1.5 to 2% in fact. I realize that ambient temperature and humidity has an impact and under certain conditions more may be beneficial but I would rather compromise and a more all around figure.

I repeated my test just to verify what I saw the first time; mix without cetaine boost and then with, same results.

And then the rain came ;(

All this messing about with the B20 Biodiesel has been fun and interesting I think it may be a bit of red herring. While it does work I/we have not proven that it has sufficient long term lubricating properties although my test engine shows no short term wear but as Andy commented on the condition of his connecting rod it may just not be good enough.

I am not sure we will ever find a substitute for ether but we have shown that you can run these small engines without it and that some is still handy for starting. During one of searches of the net I found an article on the use of ether in commercial diesel fuel use; proposed for much the same reason we have been using it - it's low self ignition temperature.

Incidentally did you know that many years ago ether was drunk like alcohol for the same inebriating effects? Those that drank ether were called (I think) ethermaniacs. Apparently the effects where shorter lived than when one drinks alcohol. And, in order to get as much ether down your throat and into your stomach, they would have a drink of very cold water first before the shot of ether. Ether was commonly available at that time and drinking it was common until they re-classified ether as a poison which ended it's easy availablity. This over 100 years ago.

for an interesting time line of Ether see: http://www.erowid.org/chemicals/ethe...r_timeline.php

If nothing else, this thread has shown that we do not need to use ether in the amounts previously specified and there are alternatives to castor oil, amyl nitrate and IPN as well.

In reference to my previous post about the self ignition temperature of mineral spirits (I can often buy it at a lower cost than kerosene) Turpintine has a self ignition temperature of 220 to 255 C. Turpentine is usually a non-petroleum product and may have some interesting properties in a fuel. I wonder what burned diesel fuel spiked with turpentine would smell like ? better? worse? Another experiment for another non-flying day.

cheers, Graham in Embrun near Ottawa Canada.

Greg,

I'm in agreement with you that automatically going to a smaller venturi for diesel isn't, shouldn't be, cast in stone. There are variables to consider, none of them it seems, predictable. My .06 and .074s don't mind the stock or even larger bore venturis. The bigger engines show signs of some compromises required. This may simply be a case where the manufacturer went way too small for likely legitimate reasons. They have to make the engine to suit all conditions and customer experience. I've been far too critical of the people who make these things, just my anal, perfectionist nature. I get it now.

The best thing is that if you have the tools, courage and capacity, JUST TRY IT. It may surprise you. While waiting for the .15 rebuild, I strayed to the glow side and discovered, by accident, but on a hunch, a fuel mix/additive that boosted performance and acceleration by a surprising amount. And this was an experiment to make up a glow fuel using locally available ingredients. Aviation oil is next to try. If it works and lubes well enough, I just may start flying .60 and up planes again. We'll, see.

Graham,

A good summation and some great links to bend the synapses into pretzels. God, I wish I had a better memory. But it's not over by a long shot. Two new ideas to try. On the bio-diesel forums, I was alerted to a product that is supposed to turn ordinary veggie oil into a fuel without the alchemy of making biodiesel.

As my experience with the virgin soy oil showed, oil will burn in our engines. Not efficiently but who knew that they would run at all. Before the taboo against electric starters was broken, yes, you could say that a model diesel will not run on straight vegetable oil. But no, as we found out, it won't START on pure veggie oil but it certainly will RUN on it. The trick is to find a combination of oil, fuel, additive and even engine design that puts it all together. Both Greg and Kelly have inspired a new experiment that involves more efficient delivery and atomization of the heavier, veggie fuel, whether it be biodiesel or straight vegetable oil. This could only be tried on a Norvel and that is next in line. First to make a number of runs on a stock engine, do the mods and repeat.

Your experience with too much ignition improver seemingly contradicts my own. I went to 10% Amsoil CB and the engine ran well enough with a much decreased compression setting. But throttling went away and never came back. There are applications where this is not an issue. Not for me. Food for thought. Need to revisit the matter.

I haven't got to the ether history link yet but it's my understanding that the anesthetic vaue of ether for surgery was known for hundreds of years but was ignored by the establishment. Much suffering in that time, going under the knife fully awake and aware. Many refused the ordeal and preferred to die. All for nothing for hunderds of years. Or so I had been told.

Off to the shop to chop alluminum.

The viscosity of biodiesel is low and I don't think the engine will hold up without additional lube. I don't think it's a good idea to use significantly less than 20% after crunching some numbers this morning. I was hoping we could go lower, but I know that the exhaust in my four strokes on 20% oil etherless is dry already. There is a property of lubricants called lubricity that is the ability of the lubricant to reduce friction other than it's viscosity. The problem is that there is no standard method of defining lubricity.

Andy, how much of your soybean oil was burning? Are you sure it wasn't just the ether burning? I don't remember a post with a run on straight soybean oil? Post 234 is what I'm referring to.

I was looking through Klotz's site again and looked at the Coxoc. The MSDS says it has a flash point of -18C and a AI temp of 180C. This is very close to ether. The odd thing is it says it freezes at 0C which is above the flash point. It doesn't really say what it is, and at 71USD per gallon, it actually costs more than John Deere Starting fluid. If I could get a small amount of it I'd try it. Nobody seems to know what the stuff really is.

The nitropropane in their Nitro is similar to nitromethane in that it carries oxygen allowing more fuel to be burned.

Greg,

That's an excellent point. I suppose I really should not have jumped to conclusions but as I see, you did try to point this out but only said that there was a lot of oil being ejected. It certainly could have been virtually ALL of the oil coming out of the exhaust.

Next step is to get some SVO, run it with the 30% ether and then take the ether out in increments to zero. That will tell the tale. Now that I have the .15 re-built with a proper, brass bushed on both ends rod, we can really beat it up with these trials. Made two so if I trash the rod, I can keep on truckin' with not too much anguish. [:@]

And about lubricity? There IS a way to test for it. That's the blown rod test. See above. [X(]

I have my doubts about the treated veggie oil. There doesn't seem to be enough happening in the pot to do anything significant.

I think someone posted this a while back.

http://www.copper.org/innovations/1999/09/oil.html

The process they go through seems far removed from glycerin and cooking.

They do make two stroke oilsand they are a bit cheaper than synthetics. They might smell nice, who knows.

http://www.engr.psu.edu/NewsEvents/E...pring/corn.htm

gkamysz,
I have noted an increase in viscosity after doing the vegi oil boiling , and also noted the amount of sediment is less than the amount of glycerine that was added so my assumption is the glycerine has combined with the oil- dont forget the glycerine molecule is a natural part of vegi oils, the amount and type of bond determines the oils level of unsaturated,monosaturated or saturated fats in the oil.

I have bioled up a small batch of "OLIVE" oil last night, I used different amounts of additives than have been listed in the process, will mix some fuel and test this afternoon. This Olive oil has higher viscosity than the cheap mixed vegi oil that I used befor so should be more like castor.
Stewart

Stewart,
I would be very interested to hear how the olive oil worked. I have been tempted by it but not yet given it a go. Did you use cheap olive oil or the virgin olive oil ? You mentioned altering the quantity of the ingredients when modifying the olive oil. are you thinking that more glycerine is better ?

Like you I also thought that the modified veggie oil was slightly thicker than before it was modified.

My friend, the one who used the modified oil mix quite some time ago is now back out of hospital and online sooner than I expected. I am off to email him and see what further info I can get.

Reg

Here's one to be going on with....

Automatic transmission fluid !

Looking at an email from my mate it appears he has used... straight 30 SAE mineral oil - avoid the multigrades with their additives. He also used commercial 2 stroke oil and reckons some people swear by automatic transmission fluid. He believes that one fuel manufacturer uses this for high stress engines such as those in ducted fan which have to run at about twice their design speed to produce effective power.

Anyone got any auto transmission fluid to hand that they can try in an etherless mix. ?
What is the viscosity of auto transmission oil like compared to ordinary engine oil ?

I have left a series of questions which I hope he will answer which might be of some use.

The caveat is.... he only ran his mixes in control line models with venturi instead of RC carb. His choice of oils may well have worked with an engine running flat out but will they work with one which needs to be throttled and is capable of good idling ?

Anyone got any comments/ideas about the use of automatic transmission fluid ? I know it is often recommended as an afterrun oil.

Reg

Straight diesel and 20% crank case drainings out of my Diesel truck:

Last night I got the engine to run on a no cetane boosted mix. The engine needs to be heated to start it and I used the electric starter. It ran but I don't think well enought to fly.



With the 2% cetane - diesel mix I now have an engine that will idle without limit at 3,000 rpm ( it will idle slower but throttle-up may suffer ) and flat out at about 8,800 RPM on the 12X6 Master Air Srew. This will fly!

Starting is very quick with about 30 sec. of propane torch and then a bump with the electric starter.

Flew all day today on eitherless- actually about 3 hours flying time. I was the only one at the field which was nice because it took alot of landing and adjusting to get things perfect. The engine definetly runs colder in the air than on the ground so you have to adjust more compression to get it right in the air. It will start by hand but it is alot esier with the starter. I warm the cylinder for about 15 - 30 seconds with the plumbers torch.

It runs about 3 minuets per OZ or about 30 min. for the 10 OZ tank.
Idle should be kept about 3,000 RPM for reliability.

When I finally got everthing adjusted right I could do touch and goes and land and taxi back and take of again over and over no problems. I could let the engine idle and even fuel it back up without ever shutting it down ( I have a seprate fueling line )

Sometimes when starting it actualy liked a little less compression other wise it would do that stop on TDC routine. The compression settings are much more sensative than with either but when it's right it's great. If it starts and runs and then stops I found that choking it till it warmed up will keep it running. It really needs to be rich to keep going if it is cold.
It was about 60 - 65 deg. F. today. I don't know if it will run so well on cold days - we'll see.

The plane would have stayed perfectly clean if there wasn't a bit of a leak at the mufler joint. I have a tube running to the tail for the exaust. If I can just get the mufler seal perfectly that will be the icing on the cake.

Thanks Andy for your expiramentation and inparation and for the Amsoil cetane boost tip!

I flew again today on eitherless. It was about 55* F. I had a bad time. It wouln't run nicely and definatly wouldn't run on yesterdays settings. It was just too cold out. I should have quit while I was ahead....... It quit after I made my take off turn when it was headed down wind at about 30'. I should have just landed down wind but I thought I could make the 180* turn. I almost did bud hit one of the steel net flight line stakes and it cut my wing back to the main spar. I can fix it but what a pain.

From now on I'm not bothering messing with Eitherless unless the temprature is over 65*

Next I'm going to run 10% either and see if that will work for the colder tempratures.

I need to build a S.P.A.D. coroplastic airplane if I'm going to be running thease kind of flying expiraments and dead sticking after takeoff Time to work on the balsa and put the fuel expiraments asside.....

Reg,

Something new to try.

About etherless mixes. I've found that even straight vegetable oil will run and run reasonably well. Starting is the issue and with heat, lots of ether prime and initial, tight compression along with an electric starter, they CAN be made to run. Lots of fuels never even considered before, will run. And if WOT is your thing, then it's just a matter of finding the oil/fuel/whatever that suits your purposes.

But as you say, throttling is a BIG issue with many of us.

I finally got my .15 re-built with a new, beam style, bushed rod. I also managed to install brass bushing in the crankcase on both ends. ZERO slop in the system.

Ran it yesterday on glow to limber it up and find settings.

Today, I ran it as diesel and tried out my stock, 40/40/20 mix. A hunch told me to leave out the Cetane booster. The result was a start with no need to alter the compression setting once warmed up. Idle was solid and the top end strong. Transition was good.

Then I added the 2% Amsoil, cetane booster. The result was a start at the last setting but a minute later, the gnarly sound of overcompression became evident and the CP had to be backed out a quarter turn. Hmmm. And now, the idle went crappy because the CP was turned out from the optimum setting for idle. Hmmm.

So I went to a mix of 70% kero, 20% castor and only 10% ether and no booster. This time, the CP had to be turned in a quarter turn from the normal start position. And it didn't need adjusting once warmed up. It DID take three or four prime runs to get it going. The high ether fuel, booster or no, started easily with just the initial prime. Idle and throttling became touchy though, I wasn't able to adjust the idle mixture to my satisfaction.

There's something here. I think there may be a chemical solution to the dilema of getting a good idle along with not needing to adjust the compression between a cold start and a normally run when hot. Likely a chemical solution along with a static, mechanical one.

The carb was also given the brass treatment in the way of a new barrel with a reduced bore. This is the carb off of the Norvel .25. The original barrel had a 5mm bore and the new one was given a 4.5mm bore. Not a lot of difference but to compare the two, it does look like a substantially reduce bore. The only result was a reduction in RPMs at the top. Throttling didn't get better on any of the fuels tried. In any case, I'll be sticking with this arrangement only because it IS more like the original .15 throttle and it should make the experiment more pure.

It was cold, about 60F and damp. As it got dark, I had to use a flashlight to get tach readings. As I did so, the flashlight beam highlighted something that I had suspected for a while. As the engine ran at full throttle, there was a substantial spray of fuel droplets pouring out of the carb throat. I was amazed at how much fuel was being ejected out the carb. A screen has been installed and more runs will be done tomorrow. The screen will serve to prevent the fuel from being ejected and allow it to be pulled back into the engine. This may or may not make a difference, as the smaller .06 has a screen as a stock feature and with or without, the engine runs and throttles the same.


Chevy,

Sorry that you busted up your plane. Yes, a SPAD would be a good idea. I'm considering that for my .15. I see that on YOUR mix, the cetane booster helped. My mix, this time, on this engine, didn't like it. Next time, I'm going to use the 50 weight Aviation oil instead of the Benol castor. If that takes me in the opposite direction, I may try a blend.

I've been thinking alot about the cetane booster. It makes the fuel quicker to light off but does it change the auto ignition temprature? They are different things I think. I thougt maybe there is an advantage to a delayed ignition. If we had delayed ignition we could run a higher compression ratio and still not get knocking and have more reliable ignition.

The thing is it really seems like the cetane booster helps the engine run.

On the straight pump diesel what I think I'm having problems with is that it needs heat to vaporize. No vaporization = dead stick. Of course Kerosene would probably help. Also I would just love to figure out a way to keep the engines temprature more stable. If I could figure out a way to keep the crankcase warmer that would help with fuel vaporization. Warming the fuel on the way to the engine with a few wraps of copper tube around the mufler could help but it still might get cold when the plane is idling. Just might have to try that though. Heating the intake air off of the mufler might work too......