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It seems pretty universally agreed that ALCO diesel locomotives smoked a lot more than others such as EMD's. 

I've never heard of one brand of diesel trucks smoking more than other trucks so it puzzles me why one diesel engine would smoke a lot more than other diesel engines.

Any facts, ideas or suggestions?

Thanks,

Jerry 
 

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Jerry,
A quick answer, turbo lag. ALCO's engine design was very different than EMD's (FMs was different than either) All ALCOs were turbo charged early EMDs weren't It gave them a very distinctive sound and a bit of smoke :)

George
 

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Even when EMD did introduce turbo on the GP-20 and later models they weren't pure turbos. EMDs are 2 stroke and 2 stroke diesels need help breathing, non turbo EMDs have blowers and in the turbo models the turbos are driven at low RPMs by a series of clutches that let go at a given RPM so that they always have the airflow needed to run. ALCOs had a pure turbo whereby when you open the throttle the injectors dump more fuel into the cylinders and the RPMs increase with the engine burning very rich, until the rpms kick the turbo up to where the boost gives enough air to even out the ratio. This all happens fairly quickly, but until that turbo catches up and the engine is burning rich it will smoke....same reason GEs smoke as well.
 

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Why did ALCOs smoke so much? I'm gonna say it comes down to peer pressure
 

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I was going to suggest "poor upbringing."
 

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We used to do the same thing with our 2 stoke Yamaha motorcycles. If a car was riding our butt in city traffic, we would shift up a couple of gears and open the throttle. The offender either backed off or went around us after being suffocated in a smelly cloud of two stoke oil and un-burnt gas. /DesktopModules/NTForums/themes/mls/emoticons/sick.gif
 

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I believe the MLW "M" series locomotives also used a clutch system for the turbo when the engine was spinning up to prevent the usual 251 turbo-lag smoke belch. Take a look at Pentrex's "Those Incredable Alcos-Volume 3" and go to the C/M636 section on the Cartier. Judging from the video, the Cartier may have retro-fitted the C636 ex-demonstrators with this system as well.   Very little smoke is evident when a M636-C636-M636 lashup accelerates a heavy ore train from a dead stop.

I grew up next to the LIRR main, and the C420's would always blast a plume of thick black smoke when accelerating from a station stop. Quite a show!!
 
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