Re: Micro 12VDC Generator with a Cox .049 Sure Start Diesel Engine

StevenStanleyBayes Sun Dec 11, 2022 11:01 pm

roddie wrote:Several years ago CEF member Ian1954 (Ian) gifted me a package that contained a Diesel conversion for a Cox Reed-valve .049. The head/contra-piston, Teflon disc (w/spares) a HD/performance replacement crankshaft and some Tygon (guessing) transparent-yellow fuel line. All as of yet untouched by me.

I bought a qt. of kerosene.. and I'd expect it to be of quality.. but I don't have experience there either ether either ether

It's the "Coleman" brand. The "Coleman Fuel" for camping stoves is known as "white gas". It's clean enough for cooking.. and I would suppose that Coleman Kerosene is of somewhat pure refinement.

I like the idea of the compression-ignition engine... I just don't have any experience yet, partially because glow engines immediately became popular here in the United States, shortly after Ray Arden introduced the glow-plug. Up until then; the spark-ignition model engines were in use. The glow-plug eliminated the need for ignition points, a condenser and an on board ignition battery. You can imagine the weight savings to a model aircraft.

The appeal of the 1/2A diesel for "me".. is that I could build a 1/12 scale balsa kit of say; a Fokker DR-1. The full-size DR-1 had an 8 foot diameter 2-blade wooden propellor. A typical Cox .049 reed-valve diesel conversion would swing a Jzinger-brand 8"d X 3"p woody effortlessly.. and with a much more scale exhaust-note. The currently available nano-RC gear makes that even more of a reality.

I have a muffler design that could easily divert waste-oil down to a sump-tube stuffed with a cotton ball. Extract it with tweezers and re-pack with a clean cotton ball between flights.

Waste-oil-handling should be considered part of the equation where excessive exposure would degrade finish-quality.. and possibly soak-through any wooden joints nearby.. or at least incorporated into the creation's venting system.

Sorry to drift the thread... This one's like a "think tank".

I have not tried this Coleman " fuel ", but, I doubt this would be good one. They can throw everything inexpensive in such a " fuel ", because, this is lit with flame and does not go directly onto the food, not a barbeque.

Castor oil collector is a good idea, I am not sure how pure the exhaust Castrol would be, but, can be collected for other purposes. Just an OPEN pipe with a plastic bottle or cap may suffice, as long as the exhaust hits something to make the Castor oil drip into the bottle or a cap. Not 100%, but, good enough and does not impede the engine.

StevenStanleyBayes Sun Dec 11, 2022 11:03 pm

roddie wrote:
I like the idea of the compression-ignition engine... I just don't have any experience yet, partially because glow engines immediately became popular here in the United States, shortly after Ray Arden introduced the glow-plug. Up until then; the spark-ignition model engines were in use. The glow-plug eliminated the need for ignition points, a condenser and an on board ignition battery. You can imagine the weight savings to a model aircraft.

The idea of a spark started ( and , even, run ) engine is amazing. I am so sorry they do not make them like this anymore. Probably, this is, even, better than a glow plug.

davidll1984 Tue Dec 20, 2022 9:14 am

StevenStanleyBayes wrote:I have written a thesis in regards to Cox .049 SureStart Diesel Engine which I would like to post here for your help, comments, ideas and general discussion.

The thesis is a rather large Word for Windows .doc document and I am unable to post this here as I cannot see a link which allows to upload documents.

I have, however, uploaded this thesis on a website and I do have the link thereto, but, I am not allowed to post links for one week because I have just registered on the forum, so, sorry, but these interested should wait for a week.

Any help is greatly appreciated.

The easiest way is to use the pc version of the site changes the layout of the menus To change it go to the top right corner in search tool bar To publish image it is in this section with youtube sign it is the first icon on the left

Micro 12VDC Generator with a Cox .049 Sure Start Diesel Engine - Page 31 Scree172

TD ABUSER Wed Dec 21, 2022 3:48 pm

I've spent a lot of time running Cox .049s this way.
Mostly on the fuel that Eric Clutton [Dr. Diesel] used to sell.
There were 2 heads that I recall....I think it was the Davis Head that did not last very long, but there was a better head that did hold up very well...[I just can't remember who made it....RJL...?]
First item of importance was to choose ONLY your best Cox engine[s] that had already been broken in on glow fuel for the conversion.
A small electric starter [like The Hornet] was preferred..but you could break a rod or a crankshaft if you were trying to spin the engine against a hydraulic lock.
Everytime you find yourself throwing the prop on start up...bet that a hydraulic lock [overcompression] is the culprit.
So...each time you start the engine you do so UNDERCOMPRESSED and gradually increase the compression until it starts "popping".
Once you think you have the engine well adjusted..sample the exhaust spray and it sould be brown and not black.
Launch the plane slightly undercompressed and "burbling" if possible because quite often compression will build during the run.
I broke my share of Cox engines on diesel...usually the rod would snap.
With the price of glow plugs today vs buying Cox replacement parts when something breaks [while running on diesel] it's kind of a toss up as to which makes more sense.
1/3 Kerosene lamp oil, 1/3 caster oil and 1/3 ether was what I used to mix if I was out of Dr. Diesel's fuel.

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Micro 12VDC Generator with a Cox .049 Sure Start Diesel Engine