The om617 injectors shoot their fuel as a tight jet. This jet then strikes the ball and atomizes.

As far as the soot is concerned, it may actually improve performance. It acts as an insulator to keep heat in the combustion gasses from escaping to the walls. So long as the soot isn't too thick or plugging anything it shouldn't be much of a problem. While scanning another diesel forum for another type of engine, I came across one guy who had his prechambers and piston heads ceramic coated to try and squeeze every last bit of power out of his engine. After spending $500 he never did say how it worked.

I think the only real critical thing on the prechambers to wear out other than the ball that Brian mentioned is the holes in the bottom. They can crack or just erode. If this happens the jets of combustion gasses may hit the walls of the cylinder, the piston, or the head. This results in a loss of power and can result in damage.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

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