Some Historic Equipment.

[FOWLER MAN]

Hi,
Thanks for that Angus.
In fact Julian the compression ratio of the Allis "O" engine was only 6.5 to 1 but they still managed to burn diesel fuel with the aid of the spark ignition.
(Most C.I. engines have a compression ratio about 16 to 1)
This engine was realy an attempt by Allis, who hadn't the resources at the time to develop a true compression ignition engine, to convert a petrol engine to run on diesel fuel. They had limmited success.
Ten prototype model L crawlers were produced with GM engines and it was the success of these that led to the introduction of the HD 14 in 1942.
Fred

[Julian]

Hi,
Thanks for that Angus.
In fact Julian the compression ratio of the Allis "O" engine was only 6.5 to 1 but they still managed to burn diesel fuel with the aid of the spark ignition.
This engine was realy an attempt by Allis, who hadn't the resources at the time to develop a true compression ignition engine, to convert a petrol engine to run on diesel fuel. They had limmited success.
Ten prototype model L crawlers were produced with GM engines and it was the success of these that led to the introduction of the HD 14 in 1942.
Fred

Thanks Angus, I can see that spraying petrol into the intake to get it started would be the answer. I can see that the engine would then run satisfactorily when warmed up a little. 6.5:1 sounds high to burn diesel fuel oil - the TVO fergies needed TVO, and TVO was needed for that reason. Never mind, perhaps they just ran with retarded ignition and an element of detonation!

Julian.

[Hutch]

Hi
the narrative with the diagram seems to indicate this is an oil engine and not a diesel (a measured charge of fuel oil into the combustion chamber.ignition,instead of depending on high compression as in diesel type engines.).This may have been a way around the problems of tvo engines where the fuel begain to condense in the ignition chamber and complete burning of the fuel was not possible with the residue going down the side of the piston into the sump with the result being more frequent oil changes and less power, also Allis Chalmers being American with their cold winters the ease of starting compared to early diesel engines may have also been seen as a possible advantage.Ricardo in England also came up with an engine design that solved the imcomplete burning of tvo fuel but due to the cost of the engines it was not a commercial success.This engine would have probably had injection pressures around 2000psi and if it was possible to ignite diesel with a spark why has no one tried it today with injection pressures near 70000 psi in fact the opposite is being tried with compression ignition petrol engines

[FOWLER MAN]

Hi All,
Heres a bit more I found in a book Re. the Allis Chalmers oil engine.
See the picture and caption below, you can clearly see the fuel injection system.
Fred

Allis Chalmers KO.jpg

img153.jpg