280SE Auto to manual conversion

[jimw723]

Hi - I have a 1969 280SE (W108/1969) with 2.8 engine (starting to get a bit of blue smoke) and auto gearbox (which I dont really get along with). I am considering swapping these for a 3.5 engine and manual gearbox (for a W108). This is my first Mercedes restoration so I am just going off experience of restoring other marques that it is possible. Has anyone done this before or know whether there are major headaches converting the auto to a manual?

PS apologies if it is a really dumb question to any seasoned vets :Oops:

Thanks in advance and regards

Jim

 

[paulcallender]

I'd be more worried about the (physical external dimensions) size of the engine and the location of all the ancillaries, etc. Can you see the two engines side-by-side? Are you happy to fabricate new engine mounts, if needs be? If you run into clearance problems on the bulkhead, I'd sack off the job at that stage.

If you have a suitable donor car then items such as the gearshift and centre console will be available to transfer, although you may end up with a little more fabricating. Oh, and you'll have to change over the pedal boxes, too, so you have a clutch pedal. The wiring shouldn't be too complicated so long as you can identify the function of the wires you pull off the old auto, since there will be a start inhibit and reverse light there.

 

[pascal]

If its a M116.980 v8 3.5 engine it should fit, as they were fitted to the 108 also (aprx 200hp): 280se/sel 3.5

the M117.980/984 (a 4.5 v8er) was fitted later on the 108 (aprx 225hp): 280se/sel 4.5

I take it you have the M130.980 inline 6 (2778cc 160 hp)the 28SE.

Am not sure the difference between that and the 280S (M130.920/921 140hp), but I would imagine that the SE has electronic fuel injection.

Why a manual? With the 4.5, you can break 60 in 10 secs, and 10.5 in the 3.5