Tiny diesels question

What's the difference between a worn-out Dyson and a wife?

One whines all the time and is increasingly reluctant to give a good suck, but the other is a vacuum cleaner.

The very specific difference between the Diesel Cycle and the Otto Cycle is that in the Otto Cycle, ignition occurs at constant volume (all at once), whereas in the Diesel Cycle, ignition occurs at constant pressure. with a Diesel engine, as the output increases, fuel is injected for longer rather than faster.

This means that carbureted compression ignition aero engines are, in fact Otto Cycle engines (like wot you sed)

Mark Rand RTFM

I do apologise for being a pedant but the reason for my remark was that a considerable number of commercial "Diesel" engines had antechambers into which the fuel was injected prior to it entering the cylinder proper.

snip

I had a 0.8cc Frog diesel when I was young in an aircraft. It was an absolute b***h. I wouldn't suggest going below 2cc for reliability

Good day, I am not much of an RC modeler but do want to build a small diesel engine for a moped. The plans on Strictly IC are the only ones I have found thusfar. Of those plans "The Dux" would seem to lend itself to upsizing to 49cc and moped use. My concerns before laying down $40 of my hard earned for the plans, are whether the moving boucing of a moped would kill this engine and will much diversion from the plans be necessary to upsize from the 10cc motor in the plans to a 50cc motor for a moped. I understand how to make it bigger and maintain tolerances but I wonder if this will undermine the process of how the engine will operate. Ideas?

Thank you to whomever takes the time, PS--I have access to a full machine shop and would rather carve than cast.

I am not familiar with that specific model engine you quote from SI, although I do know of the publication, but all the model engines I have ever come across that are referred to as 'diesel' are not strictly so. They are compression ignition engines, but are carburated with no injection system and run on a fuel that is a mix of paraffin (kerosene), diethyl ether and castor oil, plus a bit of nitrate to help it go pop. You will not be buying this stuff and a normal petrol station and if you buy it from a model shop it's going to be a damned expensive way to get down to the shops. 'though it would smell nice as you pass the bus queue :-)

Making a model engine run on diesel fuel is most unlikely and even at

50cc a pretty long shot. I have no idea where you would get a suitably small injector pump and making one would be an interesing challenge.

Rgds Richard

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Thank you for the response. I do not get to the computer often and so my replies may not be timely. You answered my question. Before posting this question I had been researching small diesels and found exactly what you expressed. --It would be a bugger-- My hope was that someone at SI site had already worked out the details but such is not the case. There is a fellow on youtube who built a small two cylinder diesel using modified automoblie injectors, but he is a diesel expert and never uses plans or writes anything down.

Thanks again

computer often and so my

researching small diesels and found exactly what you expressed. --It

a bugger--

such is not the case.

modified automoblie injectors, but he is a diesel expert and never uses

or writes anything down.

These are as small as it get!