dieselbeef

didnt know where to post this so here goes....

i hear(read) everyone wants smoke smoke smoke. i want big giant clouds of black smoke. thats cool . not for me but okay.
issue 1 is it is a total waste of fuel...correct. smoke is unburnt fuel

now looking at unburnt fuel in the cylinders you have what? what you have is atomized fuel recombining into droplets and...wetting the cylinder walls. fuel on the cyl walls in EXCESS will wash the film of oil off the cyl walls accelerating ring wear...correct so far....?

only after the turbo spool brings enough air into the cyl to keep fuel hangin in it does the smoke clear up and the lubrication return to your piston rings where required for cooling and reduced scuffing

food for thought. am i correct here??

wannadiesel

Nope. When there's black smoke it's too hot in the cylinder for liquid fuel. Washdown happens on extended idling or with a bad injector. You are likely to see white smoke when washdown is occurring.

Snapper

whoa that's deep man

catmandoo

commonly refered to as wet-stacking!my old d2 cat does it if i let it idle for long periods of time,what i get is little droplets of wet black soot,and if your just setting they fall down on ya and you look like you have some kind of weird diesel pox,but just take it and lay the blade into some dirt and get the old black smoke rollin and it comes right out of it.

steelblitzkrieg

That would mean all those city buses and tractor trailers that blow black smoke would be doing harm to the vehicle..I don't buy it.

jrs_dodge_diesel

Absolutely correct. Black smoke is incomplete combustion, but the air in the cylinder is still very hot (high EGTs), and any liquid fuel left over would evaporate.

Now wet stacking on the other hand, is primarily caused by enxtended period of idle and low EGT. That is when excess fuel starts collecting, diluting the oil and causing wear.

dieselbeef

awwwwight....just thinkin out loud

Raspy

Wet stacking sounds more like water wet than fuel wet. Water vapor from too cool conditions. Whenever the engine starts cold there is some visible water vapor. If it can't warm up the vapor will continue to form and become wet black liquid droplets. It's bad for the cylinder walls and can get to the crankcase. It also comes out the pipe as little droplets. When the engine gets to operating temp the water is carried away as dry steam and won't affect iron. The exhaust is then clear or is dry smoke.

Wetspirit

jrs_dodge_diesel

Very interesting observation. By that theory, this would more of a problem in high humidity areas rather than dry areas.

Sea:\>Drive

A good example of this and what is unburnt, partially burnt, etc... check out some of the pulling videos of the big boys (or see it in person). When those big boys start them up, they puff out white smoke (raw fuel), once they get on the line and start laying into it, the smoke turns gray then straight to solid black once the turbos light up (partially burnt).

Dieseldude4x4

Yep, what he said. Mine don't smoke too bad.

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