Sunday, 26 October 1997 Bill Wunsch wrote to Jim Dawson
 BW> When I was on the farm (and my first years in the city) you
 BW> fully expected your engines in cars and tractors to start at 40
 BW> below. The diesel tractors that showed up from time to time were
 BW> not popular in the winter. Even with oversized batteries and things
 BW> like heater plugs in each cylinder, they did not like the cold.
 BW> Aircraft engines certainly needed some heat at those temps
 Diesel starting problems are the result of two factors:
 First, the fuel is a different mix of hydrocarbons, and some of
 them turn to solid at 40 below!   Heat is needed to get them back
 into liquid form so that the fuel will move.   That could probably
 be cured by using a different brew -- I don't know, but I suspect
 a Diesel would run quite happily on Jet-A1.
 Second, Diesel ignites the fuel by compression-ignition.
 If the gases in the cylinder don't get hot enough under
 compression, the fuel won't ignite.   Hence some Diesels have
 glowplugs in the cylinders (or in the intake manifold) to preheat
 the air.
 I remember watching local farmers take off the tractor air filter
 and drip burning paraffin into the intake manifold while cranking
 the engine.   Never failed (but a bit hairy!).
 Greetings from Keith Jillings
.!. Never enough time, unless you're serving it.
--- Terminate 5.00/Pro *Ancient* *user*
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