ALL engines smoke.... some more then others. It is most notiable during take off as the engine is under its biggest load. 'Coke washing' will do nothing for a smokey engine. Coke washing is done only to remove build up of material... most likely carbons...from inside the engine. It is also done rarely as it will reduce the life of the engine. Compressor washes are more common and done on a schedules basis. Compressor washing is the application of a water based 'degreaser' to the internals of the engine. It helps remove the build ups from inside the engine, but is far less agressive then coke cleaning.
If you want to see smokey engines, just look at some of the pices from the 1960's...!!
[Edited 2007-02-06 04:00:49]
"It's not the size of the dog in the fight, but the size of the fight in the dog"