ben
Semi-Diesel
February 22, 2009 07:47PM
Hi All,,The Semi Diesel was a low compression ,injection engine,,Among the names I recall are,Hornsby-Akroid,,Lanz [Russian Cz built] Clayton-Shuttleworth,,Wichmann,,Rubb,[ Norwegian ??] ,and our Fairbanks Morse [model Y] and Munce [Indiana built] Generally these were crankcase scavenging 2 stroke engines,,low compresson,,perhaps around 150-170#,,The bulb on the end of the cylender must be preheated,,rock it back an'forth til it kicks,,its alive,,then rock it hard backwards,,the pump squirts and it fires foreward,,with enough force to continue foreward,,,There is a farm engine F-M model Y ,,shown starting, on U/tube,,,and never misses a beat,,There is good footage of Lanz also,,,With the low compresson ,these engines will pull like a steamer,,and with long [admission ] injection ,,the torque is most impressive,,There are some real impressive Lanz clips,, After watching some of these clips,I can now understand the turn of the century drivers being reluctant to abandon the old TUBE IGNITION,,Now the guys are afraid of it because they have never seen it in operation,,Oh well,,,,Cheers Ben
Re: Semi-Diesel
February 22, 2009 08:38PM
Hi Ben,


I found this after looking around some, using your refernce.


"Hot bulb engines were produced until the late 1920s, often being called "semi-diesels", even though they were not as efficient as compression ignition engines. They had the advantage of comparative simplicity, since they did not require the air compressor used by early Diesel engines; fuel was injected mechanically (solid injection) near the start of the compression stroke, at a much lower pressure than that of Diesel engines"

its from this link

[en.wikipedia.org]

even though its a wiki-link, it could help find out more about this engine.


Best



Jeremy



Edited 1 time(s). Last edit at 02/22/2009 08:39PM by Jeremy Holmes.
ben
Re: Semi-Diesel
February 22, 2009 08:58PM
Hi Jeremy,,,Look for the Wichmann - Rubb,,and the Fairbanks Model Y,,,and Lanz tractor,,on U/tube,,,Just watching says a lot,,Ben
ben
Re: Semi-Diesel
February 23, 2009 09:54AM
Hi,,,Just rememberd,,Dugald Clerk[the spelling is correct] wrote a book around 1905 I think,,on the pressureized combustion process,, BUT I can't recall the title,,It coverd gasoene,kerosene,4cycle[otto],,2cycle [briggs] maybee Brayton,,and also aceytelene as a fuel ,,AND a cycle using water for/cooing direct into cylender,,and a discussion on the jagged line on a indicator card at top,,was the pressure actually retarding the flame/pressure??? or was it momentum of the needle,,,,Ben
Re: Semi-Diesel
February 23, 2009 10:39AM
Hi Ben,

I did a search on U/tube for, Wichmann - Rubb, came up with this link, I believe there are 57 video's that will play in sequence from this link.

[www.youtube.com]


I only watched the first 3, looks quite interesting.


Best


Jeremy
Re: Semi-Diesel
February 23, 2009 08:42PM
Ben,

I love those semi-diesels and hot tube ignition. Had a wild idea that keeps creaping into my mind, with a two cylinder DA steam engine, split the crank case, use large IC pistons as crossheads, piston rod goes to top of IC piston, if 4" steam 6" IC bore, two stroke semi-diesel, low compression, fuel injected into hot tube or cup, heated by same boiler fuel(vaporizor), no valves for IC part, capacity to throttle IC air, use them as engine braking when going into a corner hot, possibility of even driving the fuel pumps off of the valve gear.

Neat trick, old system of injection, pump/low pressure fuel into a cup with lot of little rings inside it, blast compressed gas(air) through, it picks up fuel a little at a time, atomizes and throws it into cylinder. . . . hummm, well there is no lack of a compressed gas on a steamer! 600 psi boiler should be good for 300 psi combustion pressure or higher, mabey 450 psi combustion pressure.

Shrink on copper disks to cool the cylinder, piston rod "should" be cooled by entering the steam cylinder. Ugghhh, contamination of crankcase oil, air filter required, lots of issues. Steam pistons should allow you to use the IC even at really low revs, full time.

Lots of issues with this idea, such as "cheating" to get up to top speed, direct all IC exhaust into boilers burner to help draw in air, burn clean the IC exhaust, greater gass mass flow for boiler = good steam output, also shushed IC exhaust.

A few google scaned books that have semi diesels in them, even indicator cards.

[books.google.com]

[books.google.com]

[books.google.com]

I have some great "real" books that have semi diesels in them, one that presents them as a viable and "new" technology. They were generally much more reliable and lighter then "real" diesels, no carb required.

Can't find my great old book, it had a lot to say about coppers use at high temp.

Caleb Ramsby
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