Will a diesel engine fit in a 1968 mercedes 250s?
Is it an insane mod?
Anyone got one?
(CA)

the 250s is a carburated straight 6 in the w108. this engine was found in the w(114-)115 which was the mercedes diesel model from 1967 -1976 or so, so a diesel engine of this era would fit without much trouble.

i have thought seriously about putting a turbo diesel in a w115.
the replies i get from inquires is the engine bay doesnt have
quite enough room in the right places and some minor mods
would be required. the w108 engine compartment is larger,
so i would bet sizing isnt a problem.

mb was pretty good about making engine mounting the same
through its 4-5-6 cylinder engines.

sounds like a cool and workable project

don

Is possible to make the change. I have a W111 220 Sb originaly with gasoline 6 cilinders engine and many years ago an W115 240D diesel engine was fitted. No problem with the room, because the diesel 4 cilinders engine is shorter. You´ll need any modification on the electrics for the glowplugs, exhaust and intake manifolds and you´ll have to enlarge the driveshaft. No problem to connect the gearbox to the new engine

The problem of this modifications is that if you keep using an 4 gears gearbox with the short rear axle (4.01:1) of the 250S, you will get a tractor with strong but short accelerations (due to the aprox. 4000 rpm limit of the diesel engines compared with the 6000 rpm of gasoline engine) and the final speed will be no more than 120/130 km/h with the engine "screaming".

In Spain this modification was very common and useful. Some of this cars keep running with no problem, with economical use.

Best regards.

Manuel.

Spain.

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´60 W111 220b
´63 W111 220Sb
´75 W115 240D 3.0
´78 W123 300D
´88 W124 200D

Why not try with a turbocharged 617? Like from a 300DT or SD. I've heard about such a conversion. That would be very interesting to say the least.
-Joe

__________________
'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

Turbo 617 swap in was very common in Germany, since the car is taxed (rather heavily) by displacement. The diesel both got better milage and saved the owner a bundle on taxes. For the sixes, the performance is about the same. V8 owners took a hit on acceleration, but the car is still very usable.

Engine will drop in nicely, the only change might be the driveshaft length.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!