one of my friends has a 1997 E420 and i was pondering this question while i was in it today... why did they have such a limited run with the E420, and the motor for the E420? its a great car and engine... its one nice V8!

 

It just became old...the M119 had a decently long run... in the 1987 Sauber C9, the 1991 w124 400E, E420, E500, E60 and then in the 210s E420, E50, E60, E63. And of course a bunch of the S, SL, and CL V8s. It powered some fantastic cars.

Then came the M113...

 

i think the M119 engine(4.2,5.0) was much smoother(especially at idle) and more powerful than the current 4.3/5.0 V8's, I don't know why they had to switch the the SOHC 3 valves/cylinder, but I guess they're going back to the DOHC 4 valve again! yay!

 

true true, i thought it was because of cost issues associated with the engine.

what are the pros and cons of 3 valves vs. 4 valves?

 

When the emissions regulations got tighter, leaner fuel mixtures and faster cold start warm up for the cats was necessary.

The dual plugs were used to help light off a leaner mixture to insure against misfires, which would increase emissions and shorten the life of the cats.

With direct injection (the injector is in the head going right into the combustion chamber - very similar to diesel injection), there's more precise fuel mixture/timing capability since the fuel isn't being mixed in with incoming air to the cylinder.

There wasn't the need to have dual plugs any longer - now there was room to put 4 valves back to improve high rpm breathing for more power/efficency.