Loading ...Its not the ALCO engine thats the black smoke cause ..its the nature of the fuel .Diesel fuel burns slower and longer making it more suitable for high TORQUE Power at Slower speed .Thats why diesels are used for Power,NOT speed.The engine runs more efficently when its HOT .It burns the fuel more efficiently and completely when hot.The smoke is from incomplete burning of fuel when it starts up because its not HOT enough.Its a lot safer fuel to deal with for that reason.I had a diesel engine on my sailboat for that reason,i didnt need speed and couldent use it if I had it.I needed thrust to power a 7000lb ballast keel THROUGH water because I couldent get ON the water DIESEL is perfect for a sailboat and no threat to fuel explosions from GAS fumes collecting in the bilge .Thats the best example of why diesel is used ! If you want speed go gasoline or electric.Power …!Some railroads never turn their engines off even overnight sitting for hours in the Rail Yard ..It burns much less fuel when hot ! Truckers in very cold climates cant get diesel to start and use heaters on a dip stick to heat the fuel so it will start,sometimes they mix Kerosine a slightly lighter fuel in really cold climes .Most of the time in COLD CLIMES they never turn them off .Its the fuel thats causes the smoke because it need to get HOT before it burns more efficiently .Great for Power ..but the Engine has got to get HOT before its efficient.
The compression ratio is much higher by design for diesel as thats what causes the fuel to ignite..there are no “spark Plugs” ignition is aided by a hot engine since compression is constant engine..tempature is the variable to assist in ignition.
As an aside note some older aircraft carriers are diesel Powered ..I inquired while on tour of the Carrier Constellation befre it was decommissioned in San Diego ..How do you start that Darn thing I asked ? I was surprised to learn “Compressed Air ” ….