M.B.DOC:

I realize that the 6 cylinder Diesel engine is a completely new design compared to the 5 cylinder which was an update of the 4 cylinder that went back to about 1960.

What was changed that the intake and exhaust valves don't need adjustment anymore? What was the design idea for the aluminum cylinder head, just to save a few pounds of weight? I never did understand how you could bolt an aluminum cylinder head on a cast iron block and not have problems because of the fact that aluminum has three times the temperature coefficient of iron. Something has to slide and that doesn't sound good. Seems like the head wouldn't have to warp much to tighten up the cam bearing surfaces.
It also seems like the valve guides would loosen up when the aluminum head expands. Are they a press fit like the 5 cylinder or are they screwed in or attached some other way.
P E H