"Gould 0738" wrote in message
...
" How do they start it?"

Compressed air admitted to the cylinders.

Rick


One day I got to help start a big old Cleveland, 12-cylinder diesel in a
surplus US Army harbor tug. What a great experience!

The engine stood about nine feet high and
had to be about 15 feet or so from end to end.

We opened up compression release vlaves for all but one or two of the
cylinders, and then cranked her over. (I believe this engine actually
started
with an electric motor, although the compressed air is more common).

Hot dang! What a racket! As soon as the engine started firing on the
closed
cylinders, we ran around and shut the rest of the compression release
valves.
As this took maybe 15 seconds to accomplish, there was a big ol' stinky
cloud
of atomized fuel waftng around the engine room. Yee haw! For a guy who
doesn't
routinely deal with machinery on that scale, it was a lot of fun. For a
guy who
had to do it everyday for a living, (not that you'd start the engine
everyday-
far from it- it might run for weeks on end), the thrill would probably
wear off
quickly

A few years ago, I had the lovely experience of starting a Tundra Cat -
a six cylinder diesel bulldozer they used when building the DEW line.

You had to start it with a huge bar of steel pried against the engines
crank shaft. You decompressed five cylinders, opened the fuel
valves, then started cranking away. It would usually start after
four or five pulls on the cranking bar - that's what it was actually
called.

The engine was huge - the pistons were as big as my head. The
owner told me he was a construction worked (equipment operator)
and during the last fall, early spring, sometimes the engines would
freeze up - they would drop the oil pan which ran the length of
the engine and set it on fire.

Ah, those were the days.

Later,

Tom