Why merc switched to 3-valve technology?
 

Why they "think" that 3 valves per silinder is better than 4, whitch they used before eg. M119 & M120

The single exhaust valve per cylinder made for much faster warmup of the catalytic converter. This greatly reduces exhaust emissions. The M112 and M113 are rated LEV engines; very clean running for the time they were introduced.

- JimY

4V architecture>3V architecture

I'm sure that 3V is cheaper and better for emissions though.

so this is basically a step-back according to performance?

Well, yes and no. 4 alve architecture is superior to 3 valve architecture, but one simply having more valves than another does not make a better engine automatically. It is a step back as far as the design goes, but thanks to other changes, a lot of the newer 3v engines are outperforming the older 4v engines.

well yes, you are right but 99% newer engines (doesent matter what car) give bigger power output. But when i compare 48v 600 (300kw) and 36v 600 (270kw) I see that newer engine hasnt got the same performance, it has even less... twinturbo powerplant doesent suit in to the comparison, cause old 48v twinturbos were never offered (too bad :cool: ) altought newer engines are Way economic than old ones I bet...
Ok I got my answer to the question anyway.:)

$$$$ was the biggest reason for the change to the 3 valve MB engines!

MB made a good engine for a LOT less $$$ than the 4-valve engines that they were & now are making again!

Agree - they told us the engines were better but they told Wall Street they cut out half the cost.

Does the SOHC 3 valve engine still have variable cam timing?

No they don't..