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'Semi Diesel'


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Not really pretty well clued up on engines although to be fair there is always something to learn as this thread has highlighted.

 

As you have pointed out a internal combustion engine is exactly that however it is acheived.

The conclusion I have come to - going back tot he original question - is 'Diesel' has become a generic term to describe the most common form of oil engine - the diesel fueled compression ignition engine. Therefore when describing a non CI engine then it is simply called a 'semi diesel'.

 

Its all word play really, its just a good excuse for an interesting topic! :lol:

 

An interesting topic - yes, though I'm not too sure where 'word play' comes into it, unless you refer to similar instances of a declared inventor's name becoming a generic name for a type of product, such as Hoover; Kelvinator; Marconi; Wellingtons; Diesel and others. As with any science based subject, there is frequently a catch, and the pedant willl be there to correct it - like: "Therefore when describing a non CI engine then it is simply called a 'semi diesel'." That rules out spark ignition engines, which also work on compressing air and fuel but are not compression ignition.

 

Derek

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Therefore when describing a non CI engine then it is simply called a 'semi diesel'.

 

You've still not quite grasped it....

 

Even the semi-diesel requires the heat from compression to fire the fuel. It's just not enough on its own and needs the help of the hot spot to create the ignition. One or the other is insuficient to go it alone.....

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For those that like engines, can I recommend the Anson Engine Museum? It is located very near to the Macclesfield Canal at Lower Poynton, address is :-

 

The Anson Engine Museum

Anson Road

Poynton

Cheshire

SK12 1TD UK

01625 874 426

 

Great place, loads of really interesting engines, most working.

 

K

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For those that like engines, can I recommend the Anson Engine Museum? It is located very near to the Macclesfield Canal at Lower Poynton, address is :-

 

The Anson Engine Museum

Anson Road

Poynton

Cheshire

SK12 1TD UK

01625 874 426

 

Great place, loads of really interesting engines, most working.

 

K

 

 

Agreed, except that it's Higher Poynton :lol:

 

Also in a similar vein there's Internal Fire on the Welsh coast

 

http://www.internalfire.com/

 

Tim

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Lovely show of two Gas engines being started at the Anson Museum

. . and the four cylinder Gardner Semi-diesel

 

In the latter, the crankcase diaphragm valve can be seen opening and closing with every upstroke of the piston.

 

Derek

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You've still not quite grasped it....

 

Even the semi-diesel requires the heat from compression to fire the fuel. It's just not enough on its own and needs the help of the hot spot to create the ignition. One or the other is insuficient to go it alone.....

 

I was aware that compression is required to heat the fuel to a point where it will combust, but just for simplicity sake a pure compression ignition engine will ignite its fuel spontaneously when the compression ratio is around 15 -1 where as the semi at typically around 3-1 requires 'help' from a hot spot.

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These engines were originally know as ' Crude Oil Engines '

 

As it states on the Bolinder engine plaques.

 

I have a few cylinder heads with a glow plug that were used in the sixyies but every one is cracked. I woiuld suspect because with the glow plug it did not warm all the head sufficiently and the shock of the first ignition must have cracked the heads.

 

They are now correctly refered to as Hot Bulb Semi Diesel Engines.

 

 

The boatman did call the first 'full' diesel Bolinders the 'Cold Start Bolinder'

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These engines were originally know as ' Crude Oil Engines '

 

As it states on the Bolinder engine plaques.

 

I have a few cylinder heads with a glow plug that were used in the sixyies but every one is cracked. I woiuld suspect because with the glow plug it did not warm all the head sufficiently and the shock of the first ignition must have cracked the heads.

 

They are now correctly refered to as Hot Bulb Semi Diesel Engines.

 

 

The boatman did call the first 'full' diesel Bolinders the 'Cold Start Bolinder'

 

Bolinders used the 'crude oil engine' description, but I don't know whether any other makers used it. I seem to remember reading that 'crude oil' in this context is a Swedish/Scandinavian term for a particular sort of (Russian?) fuel oil, certainly not the black stuff as it out from under the ground (or under the Gulf of Mexico!!).

 

I don't think you need Hot Bulb and Semi Diesel, either is sufficient :lol:

 

Tim

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Quote Wiki "Herbert Akroyd Stuart was always keen to improve the efficiency of his engine. The obvious way to do this was to raise the compression ratio to increase the engine's thermal efficiency. However, above ratios of around 8:1 the fuel oil in the vapouriser would ignite before the piston reached the limit of its travel. This pre-detonation caused rough running, power loss and ultimately engine damage (see engine knocking for more information). Working with engineers at Hornsby's, Akroyd Stuart developed a system whereby the compression ratio was increased to as much as 18:1 and fuel oil was delivered to the cylinder only when the piston reached top dead centre, thus preventing pre-ignition.

 

This system was patented in October 1890 and development continued. In 1892 (5 years before Rudolf Diesel's first prototype), engineers at Hornsby's built an experimental engine. The vapouriser was replaced with a standard cylinder head and used a high-pressure fuel nozzle system. The engine could be started from cold and ran for 6 hours, making it the world's first internal combustion engine to run on purely compression ignition. However, to build a fully practical fuel injection system required using machining techniques and building to tolerances that were not possible to mass produce at the time. Hornsby's was also working at full capacity building and selling hot-bulb engines, so these developments were not pursued."unquote.

 

 

Quote Wiki "Rudoph Diesel, of German nationality, was born in 1858 in Paris.....After graduation he was employed as a refrigerator engineer but his true love lay in engine design. Diesel designed many heat engines, including a solar-powered air engine. In 1893, he published a paper describing an engine with combustion within a cylinder, the internal combustion engine. In 1894, he filed for a patent for his new invention, dubbed the Diesel engine. His engine was the first to prove that fuel could be ignited without a spark. (you may wish to question that statement!!!) He operated his first successful engine in 1897.

 

In 1898, Diesel was granted U.S. Patent 608,845 for an "internal combustion engine". " Unquote.

 

It would seerm to me that if these two quotes from the (sometimes) highly unreliable Wiki- ARE CORRECT. Rudolph Diesel did not invent the "Diesel" but a true compression ignition engine , capable of starting and running with no external heat input was built a full year before before Rudoph addressed the problem.

 

I have seen it in print that the reason The Associated Equipment Company (later to become AEC) and Gardners and others British C.I. engine builders called their engines "Oil Engines" not Diesels, because they refused to accept that Diesel had invented the engine and saw no reason to give him credit for it.

 

I tend to agree with this position, and see little reason to call Bolinders and the like "semi-Diesels" and feel "Hot bulb engines" better describes what they are and how they came about.

Edited by antarmike
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The Patent Dispute between Herbert Akroyd Stuart and Rudolph Diesel.

Quote Wiki""The modern Diesel engine is a hybrid incorporating the features of direct (airless) injection and compression-ignition, both patented (No. 7146) as Improvements in Engines Operated by the Explosion of Mixtures of Combustible Vapour or Gas and Air by Akroyd-Stuart and Charles Richard Binney in May 1890. Another patent (No. 15,994) was taken out on October 8 1890, which details the working of a complete engine, essentially that of a diesel engine where air and fuel are introduced separately.

 

Rudolf Diesel patented compression-ignition in 1892; his injection system, where combustion was produced isobarically (the technique having been patented by George Brayton in 1874 for his carburettor), was not subsumed into later engines, Akroyd-Stuart's injection system with isochoric combustion developed at Hornsbys being preferred.

 

Akroyd-Stuart's compression ignition engine (as opposed to spark-ignition) was patented two years earlier than Diesel's similar engine; Diesel's only patentable idea was to increase the pressure. The hot bulb engine, due to the lower pressures used (around 90 PSI) as opposed to the Diesel engine's c. 500 PSI, had only about a 12% thermal efficiency.

 

In 1892, Akroyd-Stuart patented a water-jacketed vaporiser to allow compression ratios to be increased. In the same year, Thomas Henry Barton (who later founded Barton Transport) at Hornsbys built a working high-compression version for experimental purposes whereby the vaporiser was replaced with a cylinder head therefore not relying on air being preheated, but by combustion through higher compression ratios. It ran for six hours - the first time automatic ignition was produced by compression alone. This was five years before Rudolf Diesel built his well-known high-compression prototype engine in 1897.

 

Diesel was, however, subsequently credited with the innovation despite the adduced evidence to the contrary." Unquote

 

So, I suggest, the question should be "Why call a Hot Bulb Engine a Semi-Diesel?" but there should be a second question "Why call a Compression Ignition engine a Diesel?" Dr Rudolph Diesel seems to have invented nothing, and merely worked off the back of other peoples thoughts, ideas, discoveries and products and then claimed them as his own.

Edited by antarmike
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