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Diesel anybody?

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Cuban806/07/2020 13:24:48
2986 forum posts
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On the subject of oily and smelly diesel exhaust residues..............is there any reason why synthetic oil cannot replace the castor that all commercial diesel fuels seem to contain - and how about using a much more refined and cleaner burning lamp oil in the fuel that's advertised as a replacement for use in smelly old green house heaters running on paraffin?

A fundamental engineering reason for sticking with the old familiar brew, or is it just a case of "we've always done it that way"?

 

Edited By Cuban8 on 06/07/2020 13:25:27

Nigel R06/07/2020 13:52:41
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3981 forum posts
714 photos

Weston diesel juice

"latest synthetic technology"

paul d06/07/2020 13:54:41
188 forum posts
22 photos

You can substitute paraffin for white spirit, kerosene or jet fuel, apparently white spirit smells far less once burnt.

Can't answer the oil question although I would only ever use castor as most of my engines are old and I feel it offers the best protection.

Robin Colbourne06/07/2020 13:55:02
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605 forum posts
17 photos
Posted by Cuban8 on 06/07/2020 13:24:48:

On the subject of oily and smelly diesel exhaust residues..............is there any reason why synthetic oil cannot replace the castor that all commercial diesel fuels seem to contain - and how about using a much more refined and cleaner burning lamp oil in the fuel that's advertised as a replacement for use in smelly old green house heaters running on paraffin?

A fundamental engineering reason for sticking with the old familiar brew, or is it just a case of "we've always done it that way"?

 

Edited By Cuban8 on 06/07/2020 13:25:27

Cuban8, The purists would never have that. If you don't go home stinking of paraffin and castor, the missus will think you have another woman...

Control line team race fliers have a vested interest in using the fuel which gives the most power and economy. Clearly from this article, Team Race Fuel Mix there is experimentation with synthetic oils, however it must be remembered that the engines we are likely to use are designed for castor and operate at higher compression ratios than a glow engine.

As for the cleaner burning paraffins, I don't know; it would be worth a trial.

The best bet in the short term, is to use a diesel with a well made exhaust and a tube to deflect the residue away from the airframe. The control line fliers in my club also use a long flexible tube on the cab inlet to reduce te risk of dirt ingestion. This would also reduce the amount of fuel spraying out of the carb at certain throttle settings. When not in use, if you bung the tank fill and vent pipes and plug the carb and exhaust, it should keep the gunge and smell in the model when it is in the car and house.
 

Edited By Robin Colbourne on 06/07/2020 13:59:01

Doug Campbell06/07/2020 14:00:25
106 forum posts
2 photos

I have used mineral oils, synthetic oils, and also white spirit. Fortunately with all these variations the diesel perfume lingers for days in the car to remind you of the flying session you had.

Richard Clark 206/07/2020 14:09:12
416 forum posts
Posted by Cuban8 on 06/07/2020 13:24:48:

On the subject of oily and smelly diesel exhaust residues..............is there any reason why synthetic oil cannot replace the castor that all commercial diesel fuels seem to contain - and how about using a much more refined and cleaner burning lamp oil in the fuel that's advertised as a replacement for use in smelly old green house heaters running on paraffin?

A fundamental engineering reason for sticking with the old familiar brew, or is it just a case of "we've always done it that way"?

Edited By Cuban8 on 06/07/2020 13:25:27

Most 'synthetic' oils are not really synthetic, in way of being an 'artificial' lubricant. They are still made from crude oil, which comes out of the ground. But the crude oil, rather than being broken down to the required 'thinness' is broken down fully and then rebuilt, equals 'synthesised'..

As a result they don't mix well in the high ratios needed with the other constituents of diesel fuel. Which is why such fuels, if they use any at all, only use a small proportion, the rest being vegetable oil.

Robin Colbourne06/07/2020 14:21:07
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605 forum posts
17 photos
Posted by Jon - Laser Engines on 06/07/2020 08:06:50:

I am keen to build a little 2 channel diesel model. Its been ages since i had one and i do quite fancy it.

As i have numerous diesel engines to hand the hard part is working out which one to use!

I designed a simple two channel aileron/elevator model back in the 1990s, which a friend built. It was dead simple. A parallel chord, thinnish symmetrical section wing with strip ailerons driven by a central servo. It was designed to use full-size servos, receiver and battery as that's what he had. Wingspan was 36" as that's the length of the wood, and with no dihedral, the wing was built in one piece. The engine was a DC Sabre, and the model could have coped with more power. There was no undercarriage, to keep it light and low drag.  Imagine something like a stretched 'Sharkface' with a higher aspect ratio wing.  I think it used engine bearers, but if you put a plastic mount on, you could easily switch between engines and give your diesel collection an airing.

It was great fun as you only needed the model, the transmitter and the fuel can. Maybe I took a chicken finger too?

Sometimes its easy to forget how much fun you can have with a simple model. Another friend with a similar design with a PAW 2.49 used to exercise his lurchers by flying it round a recreation ground at about 15 feet, with the dogs in hot pursuit. Fortunately when it ran out of fuel and landed, they would just lay down next to it.

Edited By Robin Colbourne on 06/07/2020 14:23:40

Steve Hargreaves - Moderator06/07/2020 15:15:50
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Moderator
6765 forum posts
197 photos

Diesels are great fun but very smelly as others have observed.

Model Technics still offer D1000, D2000 & D3000 as in days gone by...see here **LINK**

The problem can be getting hold of it. Easy enough if you live close top a Model shop that stocks it but few are willing to mail it to you. As I understand it it's classed as a "hazardous substance" & given that it's about 30% ether it's hard to disagree....

Doug Campbell06/07/2020 15:20:12
106 forum posts
2 photos
Posted by Richard Clark 2 on 06/07/2020 14:09:12:
Posted by Cuban8 on 06/07/2020 13:24:48:

On the subject of oily and smelly diesel exhaust residues..............is there any reason why synthetic oil cannot replace the castor that all commercial diesel fuels seem to contain - and how about using a much more refined and cleaner burning lamp oil in the fuel that's advertised as a replacement for use in smelly old green house heaters running on paraffin?

A fundamental engineering reason for sticking with the old familiar brew, or is it just a case of "we've always done it that way"?

Edited By Cuban8 on 06/07/2020 13:25:27

Most 'synthetic' oils are not really synthetic, in way of being an 'artificial' lubricant. They are still made from crude oil, which comes out of the ground. But the crude oil, rather than being broken down to the required 'thinness' is broken down fully and then rebuilt, equals 'synthesised'..

As a result they don't mix well in the high ratios needed with the other constituents of diesel fuel. Which is why such fuels, if they use any at all, only use a small proportion, the rest being vegetable oil.

This is not true. Automotive turbo diesel fully synthetic mixes perfectly at 15% with white spirit and ether

Engine Doctor06/07/2020 15:41:13
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2530 forum posts
39 photos

Still like diesel engines and have a largish collection and a couple simple rc models .

Advantages . Pick up model , tx and can of fuel and go fly.

Disadvantages. On arriving home the first thing SWMBO says even before hello is " Shower"

The trouble is I like the smell , always have ever since playing with my first engine a DC Super Merlin in the 50's

Robin Colbourne06/07/2020 15:56:36
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605 forum posts
17 photos
Posted by Engine Doctor on 06/07/2020 15:41:13:

The trouble is I like the smell , always have ever since playing with my first engine a DC Super Merlin in the 50's

Snap!!! DC Super Merlin, £2.75, secondhand from Ray Brown Models in Portsmouth, somewhere in the mid-1970s. Still got it. I think its in a free flight Veron Cardinal at the moment.

Mike Etheridge 106/07/2020 17:03:29
1554 forum posts
430 photos

Snap also my first engine was a DC Super Merlin bought in the 1950's from Heset Model Supplies at South Croydon. I first flew a KK Pirate and a few control line models with the Merlin, and lost it in 1962 from Epsom Downs in a Southern Junior Models Southern Dragon. The engine would run best on Mercury 8 fuel and was more sensitive to fuel choice than my friends Mills 75's which were much better engines. Many years later I made a Chatterbox for my nephew Nigel, which I think he still has with a Merlin installed ?. He used to fly Nationals Combat with Russian Diesels installed up to 2006.

Edited By Mike Etheridge 1 on 06/07/2020 17:06:43

Paul Marsh06/07/2020 17:08:43
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4065 forum posts
1223 photos

PAW in Macclesfield can get it, when they open again.

Cuban807/07/2020 09:44:07
2986 forum posts
1 photos

Thanks for the info, very interesting stuff on a subject that I only have a passing knowledge of. Just one last thing - would methanol work in our diesels as a paraffin substitute?

brokenenglish07/07/2020 10:04:17
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581 forum posts
30 photos
Posted by Cuban8 on 07/07/2020 09:44:07:

Thanks for the info, very interesting stuff on a subject that I only have a passing knowledge of. Just one last thing - would methanol work in our diesels as a paraffin substitute?

No, you need paraffin, or white spirit, or automotive diesel fuel from the filling station, or domestic heating fuel or even aviation jet fuel. All these are basically the same thing, but NOT methanol!

Cuban807/07/2020 10:11:50
2986 forum posts
1 photos

OK fair enough, but I'm interested in why it's not or can't be used - just curious. Something to do with chemistry, combustion or whatever?

Robin Colbourne07/07/2020 10:19:43
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605 forum posts
17 photos

It was suggested that kerosene (Jet A1) may be less smelly. I rather doubt this, as when I used to test aircraft fuel gauging systems, our department's unofficial motto was 'Stinkum Ad Infinitum".

Wilco Wingco07/07/2020 10:34:19
237 forum posts
3 photos

AM 10 in a KK Champ. Great fun, still have the engine which runs fine. New Champ kit waiting to get to the top of the pile. smiley

Cuban807/07/2020 11:21:27
2986 forum posts
1 photos

Methanol/Kerosene? A little on-line research says that Kerosene has an octane rating of about 15 and methanol an octane rating of about 108 so methanol's very good anti knock quality will (I guess) be working against its use in our compression ignition engines - not true diesels - whereas it's a distinct advantage in high compression spark ignition motors (methanol injection and top fuel dragsters?) Coupled to that, methanol has an energy density of about half that of Kerosene.

Comments? engine experts.

Edited By Cuban8 on 07/07/2020 11:23:47

Richard Acland07/07/2020 11:27:55
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119 forum posts
38 photos
Posted by Robin Colbourne on 06/07/2020 14:21:07:
Posted by Jon - Laser Engines on 06/07/2020 08:06:50:

I am keen to build a little 2 channel diesel model. Its been ages since i had one and i do quite fancy it.

As i have numerous diesel engines to hand the hard part is working out which one to use!

I designed a simple two channel aileron/elevator model back in the 1990s, which a friend built. It was dead simple. A parallel chord, thinnish symmetrical section wing with strip ailerons driven by a central servo. It was designed to use full-size servos, receiver and battery as that's what he had. Wingspan was 36" as that's the length of the wood, and with no dihedral, the wing was built in one piece. The engine was a DC Sabre, and the model could have coped with more power. There was no undercarriage, to keep it light and low drag. Imagine something like a stretched 'Sharkface' with a higher aspect ratio wing. I think it used engine bearers, but if you put a plastic mount on, you could easily switch between engines and give your diesel collection an airing.

It was great fun as you only needed the model, the transmitter and the fuel can. Maybe I took a chicken finger too?

Sometimes its easy to forget how much fun you can have with a simple model. Another friend with a similar design with a PAW 2.49 used to exercise his lurchers by flying it round a recreation ground at about 15 feet, with the dogs in hot pursuit. Fortunately when it ran out of fuel and landed, they would just lay down next to it.

Edited By Robin Colbourne on 06/07/2020 14:23:40

I built a Vic Smeed Miss 38 for free flight powered by an ED BEE MK miss 381. I only ever got to fly it at the Nationals as there is really nowhere near me where I can do free flight. I decided to build another with very lightweight radio gear and batteries with rudder and elevator control. This I fitted with a ED BEE MK 2 and am able to fly it at my flying patch. Although I now mainly use four stroke glow power it is nice to go back to when I was a kid with a small glow engine an oily rag and and a valve spout and not needing to go chasing after a fly away model

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