Floyd,
In the US I don't know of anyone that is mixing commercial model diesel fuel. Since Davis Diesel closed the demand for diesel in the US is very small. At one time you could get it from Morgan but not sure if they still offer it.

However most that fly the diesels mix their own using Starter Fluid as the base ether. Although J Deer is the best if you are blending a conventional diesel mix for completion, but a simple sport mix is use any starter fluid that lists ether as the first ingredient (this means at least in the US that ether would be the highest amount in the total mix usually 40 -60%) then mix this straight with 25 - 30% SAE 30 mineral oil (you need to use mineral oil not castor as the mineral oil calms down the ether for a smooth run). In the US based on MSDS sheet data several brands that are good are: Johnsen 6752 Premium Starting Fluid 50%; ACE Starting Fluid; Kleen -Flo Kleen Start. Some others that will work but have lower ether but still ok: Prestone AS237 Starting Fluid: Gunk Liquid Fire: Penray 5315 High Ether Starting Fluid. To get the SF out you could do a simple mod to the spray nozzle by drilling it out to fit a small piece of metal tube which you could fit with a section of fuel tubing, Mark the level of oil needed for the mix and the total amount of fuel you intend to mix the put the oil in first and shoot in the starting fluid. Could make up a jar with a lid and a couple of tubes to have a vent and fill, once the mix is at the final level take the fuel tube from the SF and put in onto the vent then shake the mix and go fly.

Best,   DennisT

    Hello Floyd:

    It is very easy to mix Diesel fuel.  A can of John Deere starting fluid is the perfect amount to mix one half liter of fuel.  You can easily mix 1/3, 1/3, 1/3 to get started. Lol  I mix a blend of 30% ether, 25% castor oil and the remainder kero.  This is all contained .5 liter bottle.

     Last Summer, I switched to all Diesel power and doubt if I will return to glow use!  Diesel is a bit easier as the fuel is inexpensive and devoid of the glow plug hassle.  Just fuel, flip, and fly!

     Try Diesel power.  I think that you will enjoy the simplicity.

     Good Luck,

     Frank

Mark,
The short answer is Yes, it is hard to get straight ether here in the US. Our options are John Deer starter fluid (about 90% ether per can) which is the best to mix normal kero fuel mix. Other option that work for sport fuel are any of the high ether starting fluids (these will be have ether listed as the first ingredient on the can label) and just mix them with 25%,  30 - 40 SAE mineral oil (this calms the ether for a smoother run) no kero needed as they have heptane which is similar to kero. This mix has been used in fixed compression diesels and variable compression engines just fine.

Best,   DennisT

So where is the supply of good diesel engines?

Hello David
PAW's are good engines:
https://www.eifflaender.com/engines

Frank

It's the way of the world now, not enough people are buying the things any more, PAW also make bits for the motorsport industry to stay afloat now.

They're a Good solid reliable sport engine, and if you run them right, will last you for ages.. I've got several of them in 2.5 -3.5cc range, plus a sweet little 049 sized one.

They do the job they were intended to do. Tony eifflander even  won the gold trophy at the British nats with a PAW 40.

Diesel is an interesting power option. I have flown diesel in OTS competition (and place 2nd) and had no problem with over or under runs. Tony Eifflaender of PAW won the British Nats with one of his PAW40 powered Freebirds. I had the pleasure of visiting him at the PAW factory a few years ago and he said the thing with diesel for stunt is to load the motor and take advantage of the torque. He used a wide blade 11x7 prop at a lower rpm.

Another thing with diesel is the fuel. You need to keep it cool, ether boils at around 77F. Here in Florida that's the temp we wake up to in the summer. I keep my fuel in a cooler with ICE bags and try to keep the ship in the shade, so the tank isn't too warm for first fueling. I don't mass with the needle valve and need very little compression adjustment once you get the correct run setting. I like to run high ether fuel (40%+) as it is much easier to set the needle and get consistent run time.

My only real problem is the residual aromatic smell left by the kero. This is what turns a lot of people off to diesel, not the ether (it flashes off quickly). I have been looking to come up with a fuel mix that doesn't have the residual smell and found that straight high ether starter fluid mixed with 25% SAE 30 mineral oil (without the kero you need to use mineral oil to calm down the ether) works but still has some aroma, will keep working on this.

Best,    DennisT

    In what event?!  I can't think of any event where the performance would be remotely competitive in any conditions. The exception is TR where it is rigged to make diesels the only option.

       Brett

Rigged? The same way F2B is "rigged" to encourage larger and larger  engines?  Or F2A to encourage glows? Or .... what?

Dennis

How would drug store USP mineral oil stack up against the 30 SAE requirement? Or rather, would you consider it too risky even to try such an oil? By the way, I tried it out using a low ether (non John Deere) starter fluid with the drug store mineral oil on short (primer only) runs. Impressive! What say ye?

Dave Mo…

The rules are designed to ensure alternatives are not competitive.

Rubbish. Because of the nature of team racing the whole idea is to ensure that you can't complete the required number of laps on a single tank full. Hence the need for a TEAM member who's job is to restart the engine. To make certain there has to be a pit stop(s) the tank is limited to 7cc. Now if you can come up with a fuel that works in a glow engine but sips fuel as frugally as a diesel does then have at it. Nowhere do the rules state you must use a diesel, it's simply that a diesel is best suited for this particular competition.

Rubbish. Because of the nature of team racing the whole idea is to ensure that you can't complete the required number of laps on a single tank full. Hence the need for a TEAM member who's job is to restart the engine. To make certain there has to be a pit stop(s) the tank is limited to 7cc. Now if you can come up with a fuel that works in a glow engine but sips fuel as frugally as a diesel does then have at it. Nowhere do the rules state you must use a diesel, it's simply that a diesel is best suited for this particular competition.

   I know what the rules are, you might remember my offer to keep the USA TR team from getting unsupported by getting a bunch of stunt guys to build "goat" models with 15FPs and just do 15 pit stops. Uncompetitive, but intended to raise entries enough to not run afoul of the AMA blue book.

   But, you know you that can't be competitive, and the 7cc was set to make impossible to do with a glow engine, you'd have a tough time getting its started on 7cc of prime. Also, trying to fly glow engines would raise the performance so much that either flying it on the short lines, or 3-up, would be dangerous.

    The current participants want it to remain Euro diesel racing, so they altered the rules to make sure that was the only thing that could be competitive. If that is what everyone wants, then fine, but don't pretend it is anything other than trying to maintain the status quo. I certainly don't care one way or another.

    FAI F2B is similar -  yes, it's legal to run any engine you want, but in fact, the rules have been rigged to encourage RTF models (no BOM) and electric (restrictions on IC engines but almost anything goes in electric). The people doing it made no bones about it, they wanted to favor electric, and wanted to pander to buy-and-flies. I and many others *do* object to that, because it is demonstrably *not* what the participants want - recall the rejected Appearance Points rule that everyone agreed to and the F2B working group "passed" - and then was killed by the CIAM by the usual FIA bullshit.

     Brett

   

   

Dave M,
No, the drug store mineral oil (or castor) will not calm the ether the way SAE mineral motor oil does. Mineral Motor Oil has some aromatics in it and that is what does it.

Best,   DennisT

Dave,
For glow fuels the drug store oil is OK. For diesel if you use a old standard 1/3;/1/3/; 1/3 of ether; kero; oil then it is OK as long as the kero is not odorless, if it is odorless lamp oil use the motor mineral oil (this is just plain old gauge store motor oil) to calm the ether. If you use just the starting fluid use the motor oil.

Best,    DennisT

Sorry for a silly question, but what’s the urge to use these ”drugstore” oils and mineral oils? You can get proper castor, synthetics and blends from Klotz, for example, that also work with diesel fuel.
Also, the Maxima #927 mentioned in the previous post is very good, maybe the best oil actually. L

 The oil issue is one that has been around for years. When ignition was king they used white gas (Coleman fuel today) and mineral oil (some called for 70SAE gear oil (gear oil is graded different than motor oil, the equivalent motor oil grade is 40SAE). Mineral oil is a very good lubricant, and protects our model engines just fine. When glow came on the scene the methanol became the base fuel. Mineral oil will not mix with methanol but castor oil was about the same viscosity and film strength as 40SAE motor oil and does mix with methanol. So castor oil became the base oil for glow.

In the diesel world guys became convinced that castor was the way to go. Problem was that castor does not mix well with what became the base for diesel - Kero. But since we still needed ether and ether is a very good solvent it allowed the castor to mix with the total fuel mix. Mineral oil still works just fine but it was not the first choice as the top flyer were all using castor and that was what was selling.

Some have tried the Drug Store high purity mineral, but it doesn't work as well as plain old motor oil to give a smooth run as it lacks the aromatics in motor oil.

Best,   DennisT

SP,
First off I'm an ME not CE so not trying to be a SME on motor oil. The motor oil aromatics are very slight only a little smell not as strong as kero. I don't know the complete chemical names. This is just unscientific knowledge that has been around in the diesel sector since the 1940's with the Drone Diesel. I don't have the specific combustion details just know it works and it has been discussed by others (Adrian Duncan for one in his article https://adriansmodelaeroengines.com/catalog/main.php?cat_id=356) that are much more knowledgeable on diesel operation than me.

I know that in those areas that have easy access to ether the old standard diesel mix of 1/3, 1/3, 1/3 works fine for engines with variable compression. In the US two things go against diesel. First getting commercial model diesel fuel is very difficult it not impossible for most guys. Second, the standard mix with kero leaves a very strong aroma that gets on helper's clothes, that glow fuel doesn't, so it's hard to get a helper for holding/launching diesel.

Best,    DennisT

Jerry,
Interesting, I don't know the type of ether that is, best for model diesel fuel is diethyl ether. it has an autoignition temperature of 320F. Other ethers might work but they will need more compression as their AI temp is higher.

Best,    DennisT