Bruce in alaska wrote:
In article ,
"Percival P. Cassidy" wrote:

I understand that the IH TD-x tractors/'dozers had an additional valve
in each cylinder that opened to an "extension of the combustion chamber"
(for want of a better term) in which the spark plugs were located, thus
reducing the compression ratio; petrol/gasoline would have exploded
rather than burned with a diesel-appropriate compression ratio. They had
spark plugs, magneto and carburettor as well as injectors. There were
two controls to effect the changeover, IIRC: one near the left front
(perhaps to switch fuel supplies), plus a lever accessible from the
driver's seat. Clouds of black smoke at the changeover.

I have a Austin/Western Grader that has such an IH Engine in it. It is
a Gasoline Engine on one side, (Carburetor, Distributer, Coil, and
SparkPlugs) and a Diesel Engine on the other side (Injection Pump,
Injectors, etc) To Start it, You opened the Gasoline Fuel Valve, put the
Change-Over Lever in Gasoline Mode, add about 1/2 Choke, and Crank.
Starts within 25 seconds, even down at -15F. Once started, you slowly
open the Choke, as the engine warms up, until it is wide open. Then wait
5 minutes for the block to warm. Once it is warm, you move the Fuel
Rack of the Injection Pump from Cutoff, to Idle, and watch the resulting
Black Smoke to turn to Dark Gray, and then move the Mode Lever, to
Diesel. WollLa, you now burning Diesel, and you can turn off the
Ignition System, and shut off the Gasoline Fuel Supply. Shutting down
the engine is the above, in reverse. If you don't do the shutdown, via
Burning Gasoline, you have a lot harder time getting the engine to
Start, next time you want to run it.


Was that maybe because if you shut it down on diesel, the cylinder and
plugs and such would be coated in diesel and not fire well?

I remember a friend of my dad that had a tractor with three tanks. He
had color-coded them, red for gas, green for diesel, and blue for water.
ISTR when running on diesel it also used a bit of water in the
cylinder. To help compression?

daestrom