PeachParts Mercedes-Benz Forum - View Single Post

Jeremy5848 · #5 07-27-2009, 03:30 PM

In theory, conversion to a common rail injection system is possible, given a talented person such as yourself, equipment such as you have, and wads of money. The results, however, would not justify the expenditure unless you simply wanted to use it as a learning experience. You might be able to improve the fuel economy beyond the current 30-ish but the NA block, as KarTek says, will not support much more power. To the list of expenses you would also have to add the value of the car as it is now, since the resale value of the car would almost certainly be negatively impacted.

Since you have a W124 chassis, it would be more practical and perhaps just as much fun to retrofit a 603 engine, since it is turbocharged and comes in two flavors, the "regular" 3 liter version and the rod-bending 3.5 liter version that was in the S-class cars for a couple of years. Since the W124 chassis was originally built for the OM603 engine, it should not take much work to stuff one in a newer version of the 124 chassis.

It would be a challenging project to rebuild the engine with the updated (supposedly) non-bending rods, an intercooler, and an aftermarket boost controller. You could then look into modifying the injection system. However, because Mercedes uses indirect injection, you still might find that the results were limited. Whether an existing head could be machined to accept direct injection is beyond my limited knowledge of diesel systems.

I believe that some people have tried to put an OM606 turbo engine in a W124 chassis. The problem there is the electronics. It would be interesting to see if the mechanical IP from the engine in your '95 could be fitted to the '98-99 turbo engine. If you could get rid of the electronics, the project would be a lot easier.

Jeremy