Is it time to bring out the Diesels?

[frank mccune]

     Hi All:

     With the high price of glow plugs and glow fuel, is it time to return to using the Diesel powered planes again? I have three Diesel powered planes that are ready to fly plus at least five liters of fuel. 

      Anybody else ready or a walk on The Wild Side?

       Frank

   

[Dennis Toth]

The diesels will do the job, they run very similar to electric when set up right. When I was in the UK a couple years ago I went to the PAW factory and met with Tony Eifflaender. He is a British national champion, he said the diesels  for stunt like a bit of load and run more pitch then glow setups. On his ship with the PAW 40 he ran and 11x7.

Here in the US it is hard to find commercial model diesel fuel but there are simple mixes with starter fluid as the base that will work for stunt and sport flying. The best starting fluid is John Deer, it has around 80% ether. you could mix 1/3 JD plus 1/3 kero and 1/3 oil you could add 2% Amsoil Cetane improver to reduce compression. Another mix is with high ether starter fluid like Johnsen's Premium Starting Fluid 50%,  10.7oz from NAPA. With this you mix 73% Johnsen and 25% 35 SAE mineral oil (no kero) and 2% Amsoil Cetane improver. With the Johnsen and other SF like it they have heptane as the balance which is similar to kero but is doesn't calm down the ether and you get a lot of pre-ignition (knocking), the mineral oil does this. You could do a oil blend with say 5% castor but mostly mineral oil.

If you have a fixed compression Drone Diesel the fuel mix is 73% John Deer and 27% 35 SAE mineral oil, they run at around 5500 rpm on and 11x10 or 12x8 wide spoon blade prop. Will pull a 52" Zilch easy.

Best,    DennisT

[Howard Rush]

     Hi All:

     With the high price of glow plugs and glow fuel, is it time to return to using the Diesel powered planes again? I have three Diesel powered planes that are ready to fly plus at least five liters of fuel. 

      Anybody else ready or a walk on The Wild Side?

       Frank

Do I smell limes on your breath?

[Dan Bregar]

I think I still have a pint of Hexyl Nitrate somewhere 

[50+AirYears]

Well, I HAVE been curious to try my Cub .049 and Aurora .15 Diesels..  I wonder, some OLD recipes I've read about have mentioned using things like Truck diesel or gasoline in the mix.  Well, with today's lead less auto gas...

[David Murrell]

Tony, truck diesel works in place of kerosene but you still need castor based oil, try the go cart racers for oil, petrol won't (shouldn't ) mix with castor oils. Ether as above if not available from someone who knows where to get it.

Enjoy the noise and smell, just be careful running them in.

Cheers

[Dave Hull]

If you are going to run diesels, you will need to add a couple of tools and operating aids to your flight box:

1. A compression wrench that won't get tangled up in the prop;
2. A chemical ice pack for the banged knuckles as you wander around looking for a compression setting;
3. A pair of sharp scissors to cut the diesel spills out of your shirt and pants. No other way to get rid of the stains and the smell.

McDivot

[Dennis Toth]

One of the things that holds diesel back here in the US is the residual smell of the burnt fuel. Granted the raw fuel ether smell is strong but that flashes off quick and when running burns. The residual oil left on the ship is what is hard to get rid of. This seems to be from the kero used. The kero has aromatics that linger. Some have tried to cover it up with various scents added to the fuel but now you have foo-foo smell and aromatic, kinda like throwing cologne on after working up strong BO, smells twice as bad.

I have tried to do a kero less fuel using high ether starter fluids. With out the kero you need something that calms the ether from detonation. Mineral oil (straight wt 35 SAE) does this and provides very good lubrication. This mix is not the most powerful but for stunt and sport flying is OK. In these starter fluids like Johnsen's Premium Starting Fluid 50% you get 50% ether and the balance is heptane which has similar heat value to kero but no aromatic smell. To do the mix you need to set up a jar with mix levels marked on the side for the ether and oil. Put the oil in first then have the lid in place with a small hole to insert the tube from the starter fluid straw, spray in the SF, mix, fuel ship fly. I like to have all the components in a small cooler with a few ice packs to cool them. Don't let the ship sit in the sun after fueling, the ether can evaporate and change the mix. 

Attached is a Excel spreadsheet with Starter Fluid brands, chemical info and various diesel fuel mixes.


Best,    DennisT

[bob whitney]

cant open it

[kevin king]

Do I smell limes on your breath?

[Dennis Toth]

Here is a older format MS Excel spreadsheet hope you can all open it.

Best,  DennisT

[FLOYD CARTER]

It seems that all the high-performance diesels have 360 deg. exhaust porting.  Without a good way to collect exhaust and route it away from the plane, you end up with a gooey mess all over everything.  That black exhaust crud is difficult to remove, and it gets everywhere; in hinge lines, and places you can't reach.

I do run diesels, but not often, and in planes where the exhaust goo doesn't bother me.

I have my own car, so diesel smell in the upholstery doesn't  get me into trouble with my wife.  (we just celebrated anniversary #64, so she's now being nice to me.)

[Norm Furutani]

Shoot!
I was just thinking about building a vintage FAI FF. A Wheeler "Eliminator" for a 1.5 Webra Record. I forgot about the smell!

Norm

If you are going to run diesels, you will need to add a couple of tools and operating aids to your flight box:

1. A compression wrench that won't get tangled up in the prop;
2. A chemical ice pack for the banged knuckles as you wander around looking for a compression setting;
3. A pair of sharp scissors to cut the diesel spills out of your shirt and pants. No other way to get rid of the stains and the smell.

McDivot

[L0U CRANE]

Dennis,
 
Thanks for the XL! Didn't realize JD contained heptane. I'd tried using other starting fluids that were mainly heptane many years back. Found it needed way more compression than ether, and ran harsher, with little tolerance for slightly off settings. Di-ethyl ether is so much better.

I first ran across that comment on scissors on the UK Barton site. It was worded as:,,,"how do you get diesel stains out of your clothing? Scissors..."

You can always tell a diesel flier by the unmistakable manly AROMA...(another quote from Barton site, w-a-ay back.)

[john e. holliday]

I remember the smell of the fuel when Dunkin&Wright would be practicing with F2C plane.  Then they loaned myself and my team mate a plane with a Super Tigre engine.  First off was teaching my team mate how to fly an F2C plane.  I got used to the smell, but the wife didn't.  House I lived in at the time had stairway from back door to basement where I would go to take shower and change clothes.   A couple of years ago I got out my Rivers 2.5 and mixed some fuel using starter fluid and kerosine from ACE Hardware plus my castor oil.   Had to teach myself again about starting diesels again.  If only I could get ether locally I would be set with diesels I have.  Oh, the wife didn't complain about the smell this time.

[GERALD WIMMER]

Hello I have always enjoyed running diesel engines especially the nice ones (that cost a bit more and usually with ball races). The smell is part of the fun and the whole family is very used to it. Sometimes I will start one up inside when cleaning them after flying with left over fuel, helps build everyone's tolerance levels and perfumes the house! Actually the second motor I got for my wife was a PAW 19 that she wore out and it needed a new piston/cylinder teaching her to fly and then to stunt. My youngest son Max loves the diesel 'challenge' .
 For cost glow fuel is a lot cheaper here then diesel and electric and gas/petrol seem to dominate overall motor sales now.

Regards Gerald

[John Park]

It seems that all the high-performance diesels have 360 deg. exhaust porting.  Without a good way to collect exhaust and route it away from the plane, you end up with a gooey mess all over everything.  That black exhaust crud is difficult to remove, and it gets everywhere; in hinge lines, and places you can't reach.

It's true, the older diesels fling exhaust muck everywhere, and there's not much you can do about it.  However, the silencers PAW supply for their engines, in addition to being very neat and small, have their outlet very conveniently arranged to take an extension, so that the exhaust goo can be routed clear of the model.  Diesels are less sensitive to back-pressure than glow motors, and a three- or four-inch extension tube doesn't rob a noticeable amount of power - not for C/L stunt applications, anyway.
Another good thing about diesels generally is that neither the raw fuel nor the exhaust goo will attack nitrate dope - until I started running glow motors I never used anything except nitrate dope and car cellulose - fuel-proofer wasn't necessary, and I still don't bother with it on my diesel models.  To clean the model after a flying session, petrol (gasoline) works well on a rag or paper towel.

John

[Dennis Toth]

One thing I've been trying to work on is a diesel fuel mix without kero that doesn't have the heavy residual smell. For this I've been looking at using straight starter fluid and mineral oil with a bit of castor. It seems that since most starting fluids have mixtures of ether and heptane and heptane is similar to kero this should work. Various searches on the net have shown that some diesel people have done this and it runs fine. The best starter fluids to work with will list ether as the first component, this indicates the ether is the highest % component. In the spreadsheet I posted I have listed several brands that meet this. It might also work with lower content starting fluids but it should have at least 40% ether to get the fuel mix with at least 30% net ether after adding the oil. You need to use 35 SAE straight weight mineral oil to calm the ether from detonation, Castor or Syn's won't do this.

The diesel fuel mix from the SF/oil approach while not the most powerful fuel for racing is not bad for stunt or sport and should be reasonable cost.

Best,    DennisT

[Paul Smith]

I had a couple of diesels for a while when I was working on the CL endurance record.

If I continued to use diesels I would have needed a dedicated car, clothes, and storage shed for the stinkies.

Apart from the kerosene smell, the ether has become a prohibitive controlled substance, thanks to a single free basing incident by Richard Pryor.

[Brad LaPointe]

My negative Diesel experience began at the 1994 WC in China . Our team were allotted two rooms to store our equipment. The stunt guys and speed guys took one room . Us combat guys ended up with the team race people. Since at the time I worked for a chemical company my MK 1 nose detector was working overtime trying to determine what cancer causing agents were present in our room .

During the practice week the chemistry experiments continued. I was wishing for a Scott air pack just to grab the combat gear . Things got really serious one night . The next morning our room looked like a bomb had gone off . In fact one had . One of the science experiments stored in a glass container had exploded during the night . Glass shards everywhere. How the whole place didn’t burn to the ground l will never know .

To this day I will never understand why team race  doesn’t have supplied standard fuel without the exotic chemicals . Of course we kept the ah @#$% moment quiet . Personally I was convinced that Diesels were never going to be a part of my model experience .

Brad

[Dave Hull]

Has anyone tried the "odorless K-1 substitute?"  I bought a jug for testing, but haven't mixed a batch yet. (I'd rather test it on a sport motor than on a racing motor....)  I bought the Klean Strip brand from the Home Despot. It is sold for use in heaters and stoves.

Dave

[L0U CRANE]

Re: The mess and stink of diesel fuel...

I found quite a while ago that ordinary auto diesel, that pump alongside the gasoline pumps at almost all stations, runs cleaner, with less 'essence of filthy bilge.' It also handles - near as I can tell - just like the other "kerosenes" in many "diesel" fuels. Price is another possible advantage, even if it has often cost a bit more than standard unleaded gasoline.

I've seen "high purity kerosene"  that cost over double even the recently increased price of pump kero or gasoline. Didn't try that stuff. Did some wok with auto grade diesel from filling stations.

Consider: it is there for private cars. It does not stink like the usual mix we use. It seems easier to set a good needle/comp combo and still have the residual exhaust oil at worst a dark honey color. Softer settings don't go that dark. (In my benching experience, anyway.) Haven't had recent experience flying such blends for several reasons...

The recent discussions of John Deere SF are welcome. I have a method of getting the volatiles out of the spray can safely and with minimum waste. Find a spray nozzle with a straw that fits the the JD can's supply tube. Set up a  quart jar with two lids. One intact to make a good seal. Punch a hole through the other lid large enough to pass the straw and allow some breathing around it. Spray through the straw into the jar. When you have as much as possible in the jar, switch to the sealing cap. Or, when all the propellant pressure is exhausted turn the can upright and punch several holes in the rim to pour out any liquid still remaining. THEN switch to the sealing cap. Plumbers' teflon tape adds to the threads' seal.

[qaz049]

Interesting that it's the US based people that complain about the smell of diesel fuel. It's rare to hear the same complaints from people in places where there's a vibrant diesel culture. I wonder if it has something to do with the quality of Kerosene available in the US?

[GERALD WIMMER]

Hello
It does make me wonder too if the Kerosene does have a different odor between regions and brands.  When I have made up diesel fuel using my Tractors pump diesel it smells stronger and burns dirty compared to supermarket brought Kerosene. When spilling diesel it all over yourself which I have done a few times topping up the fuel (with Jerry cans ) on our John Deere and Same tractors it irritates the skin and gives you a good headache till you've showered and changed, thankfully flying diesel powered model airplanes is never that extreme and very pleasant by comparison.

Regards Gerald

[Air Ministry .]

What about this ' Jet Fuel ' Airplane engine Kero , then . JET 1 or something .

[richardm]

Lamp fuel or some of the naptha blends have less odour, but personally I like the smell, takes me back

[Dennis Toth]

If you use the odorless kero you will need to use 35 -40 SAE straight wt. mineral oil to calm the ether down and prevent detonation (knocking). The simple starter fluid with mineral oil mix works for stunt and sport flying.

Best,   DennisT

[L0U CRANE]

Errata for my recent post...

It's a typo! I did not stir-fry any #2 diesel. I did some work with it...

More practical note:- Once you 'capture' all that's possible from the JD spray can in a glass jar and seal it, blend up your batch of ready-to-fly fuel soon after. Not that it is likely to lose running qualities, but that a fragile container with several ounces of ether isn't very wise to have around. heat expansion pressures. Flammability if the jar breaks... Common sense...

TO Air Ministry - if you can find a source of aviation jet fuel. it should be good.  There are several grades of aviation jet fuel. Some are deliberately kept impure and dirty to reflect likely conditions on board ship or in the haste and difficulties of land combat needs. The MilSpecs were of interest for a project I worked on with a friend about 20 years back. "Kerosene" fuels are 'safer' than gasoline fuels. They are much less  likely to go  into a raging fire, like those that destroyed or damaged a few aircraft carriers in WW2 and caused dire risks in other conditions.

[David Murrell]

Agreeing with Matt (air Ministry) and Lou, a trip to the local airport fuelling facility and you might be able to procure a litre/gallon of commercial jet fuel, as good as it gets Cheers

[FLOYD CARTER]

In the past, several have recommended Lamp Oil instead of kerosene.  I have a bottle of lamp oil (for our lamps) but haven't tried it for diesels.  It really doesn't have any smell.  Lamp oil is sold in most of the large hardware stores.  Used for those outdoor patio "Tiki" lights.

[John Park]

In the past, several have recommended Lamp Oil instead of kerosene.  I have a bottle of lamp oil (for our lamps) but haven't tried it for diesels.  It really doesn't have any smell.  Lamp oil is sold in most of the large hardware stores.  Used for those outdoor patio "Tiki" lights.

Many years ago, there was an article in AeroModeller that mentioned the use of lamp oil in place of kerosene (or paraffin, as we call it).  As I recall, it said that lamp oil was so much more 'oily' than the domestic heating paraffin we commonly used when we mixed our own fuel, that the proportion of lubricant could probably be reduced without danger.  Sounds reasonable, but I never heard of anyone trying it: I'd imagine 20% castor oil instead of 25% might be safe enough - but that is just a guess.

John

[Dennis Leonhardi]

Forgive me for shameless self-promotion, but I've listed a literally new PAW .19 RC engine with silencer in the Classifieds.  Standard venturi and needle valve assembly are readily available last time I checked.

In response to a remark by Floyd Carter, I think PAW does a good job with their silencer in "routing away the exhaust" (and slime) ...

Then again, I'm often wrong.


Dennis

[John Park]

Forgive me for shameless self-promotion, but I've listed a literally new PAW .19 RC engine with silencer in the Classifieds.  Standard venturi and needle valve assembly are readily available last time I checked.

In response to a remark by Floyd Carter, I think PAW does a good job with their silencer in "routing away the exhaust" (and slime) ...

Then again, I'm often wrong.


Dennis

A handy thing about the PAW silencer is that you can install it in several different ways.  On the .09, .15 and .19, with the three-bolt cylinder jacket, it can be fitted across the rear, exhausting to left or right, or slanting back at a 60 degree angle on either side.  The very short tailpipe has a groove round it to aid the attachent of a silicone rubber tube extension - diesels are quite tolerant of back-pressure and a three- or four-inch extension tube doesn't seem to rob a signnificant amount of power, while helping to direct that horrible diesel exhaust gunk clear of the model.

John

[Dennis Toth]

John,
One of the issues with using lamp oil is that it might not calm down the ether like normal kero does. One way I know to keep the ether calm (no detonation) is to use mineral oil (SAE 40 wt is the same weight as castor). The old Drone Diesel use 75% ether and 25% mineral oil. I think mineral oil fell out of favor when glow fuel started to dominate the hobby cause mineral oil doesn.t mix with methanol. The old sparkers also used mineral oil. Mineral oil is not a bad lubricant, also inexpensive and readily available.

Simple diesel mix is high ether contain starter fluid (should list ether as first ingredient on can) mixed with 25% mineral oil. If you have some Amsoil Cetane improver or Royal Purple Max-Tane (also cetane improver same base stuff) could add 3 - 5%.

Best,    DennisT

[Chris Wilson]

In regards to diesels being tolerant to back pressure, I disagree.
ANY pressure change drastically changes their ignition point, just try using a tuned pipe .
What happens here is that ignition is complete far sooner than a glow engine that has a rolling flame front and so the remainder of the power stroke acts as a buffer for any negative pressure wave, but time that pressure wave sooner and the engine goes hard and overcompressed from pre-ignition.
The tolerance with back pressure stems from backing off the comp.to avoid the above.
Chris.

[Chris Wilson]

To this day I will never understand why team race  doesn’t have supplied standard fuel without the exotic chemicals .

Brad

The problem is that what is 'standard'  in one country or region will never be in another.
Kerosene is a variable hydrocarbon soup that greatly effects how engines run.
Chris.

[Chris Wilson]

It seems that all the high-performance diesels have 360 deg. exhaust porting.

That is simply not true and Dr Schnuerle would rolling in his grave by now.
Chris.

[Howard Rush]

I have a bottle of lamp oil (for our lamps)...

Lot of good it did to teach you EE.

[John Park]

John,
One of the issues with using lamp oil is that it might not calm down the ether like normal kero does. One way I know to keep the ether calm (no detonation) is to use mineral oil (SAE 40 wt is the same weight as castor). The old Drone Diesel use 75% ether and 25% mineral oil. I think mineral oil fell out of favor when glow fuel started to dominate the hobby cause mineral oil doesn.t mix with methanol. The old sparkers also used mineral oil. Mineral oil is not a bad lubricant, also inexpensive and readily available.

Simple diesel mix is high ether contain starter fluid (should list ether as first ingredient on can) mixed with 25% mineral oil. If you have some Amsoil Cetane improver or Royal Purple Max-Tane (also cetane improver same base stuff) could add 3 - 5%.

Best,    DennisT

Back in the good old days of the 1960s, when you could get technical ether and even amyl nitrate(!) over the counter in my local pharmacy, my formula was 25% Castrol R (a mineral/castor oil blend, commonly used in speedway bikes), 30% technical ether, 43% domestic heating paraffin and 2% amyl nitrate.  This was regarded as a standard formula, and came out a lot cheaper than commercial fuels.  At one point I used straight SAE 50 mineral oil (Castrol Grand Prix), but found it unsatisfactory: it wore out one of my engines in no time.  (I had it rebored by Gig 'Mr. PAW' Eifflaender, and it still runs beautifully, on castor-based oil of course.)

Regards, John

[Dennis Toth]

John,
Interesting information. What part of the engine was bored out - shaft or piston bore? I like the idea of adding say 5% castor with the mineral oil. You indicated home heating paraffin, is this what we in the US would call No. 2 heating oil? For comparison No.2 oil (diesel fuel in the US) has an auto ignition temperature of 510F (265C), kero's AIT is 428F (220C). With that base fuel you need significantly higher compression which bets up on the bearings. If you run higher ether content you could use less compression and save the bearings.

Attached is a simple Excel spreadsheet that lists various starter fluids and their ether content (from MSD sheets) plus a sheet on different chemicals used in our fuels with as much info as I could dig up.

Best,    DennisT

[John Park]

John,
Interesting information. What part of the engine was bored out - shaft or piston bore? I like the idea of adding say 5% castor with the mineral oil. You indicated home heating paraffin, is this what we in the US would call No. 2 heating oil? For comparison No.2 oil (diesel fuel in the US) has an auto ignition temperature of 510F (265C), kero's AIT is 428F (220C). With that base fuel you need significantly higher compression which bets up on the bearings. If you run higher ether content you could use less compression and save the bearings.

Attached is a simple Excel spreadsheet that lists various starter fluids and their ether content (from MSD sheets) plus a sheet on different chemicals used in our fuels with as much info as I could dig up.

Best,    DennisT

Dennis:
In the 1950s and '60s, Progress Aero Works (PAW) offered an invaluable service whereby engines with a worn bore would have an oversize piston fitted and the bore honed to a proper fit.  The service was cheap and fast, and many people found what I did: when the rebored engine was properly run-in, it started better and had more power than ever before.  They rebored two engines for me, both of which still start and run very well despite a lot of use back in the old days.
I recall that the ether you could buy over the counter in the 1960s was called 'technical ether' or 'ether solvent', to the British specification BS579.  It was supplied as a chemical reagent for laboratory use, and wasn't refined to the same degree as anaesthetic ether, which made it cheaper.  Paraffin was freely and cheaply available - every gas station had a pump that dispensed it - and was commonly used in domestic heaters: it burned very cleanly and was practically odourless, and I imagine it would have been equivalent to your No. 2 heating oil.
I've just remembered - the first diesel I ever owned was a second-hand ED 'Bee' (1 cc.), which turned out to be worn and hard to start: I understood why when its late owner told me he'd been running it on a mixture of half-and-half anaesthetic ether and 'Redex' upper cylinder lubricant!

Regards, John

[FLOYD CARTER]

Howard.  In spite of my extensive engineering background, I sometimes go far afield and dabble in model airplanes and stuff like that.  I hope the engine experts (and all others) on these forums will bear with me as I explore arcane subjects like model airplane motors.  (I would never venture into the Wing Turbulator issue).