Putting a M116 into 280S

[Nabstud]

I'm looking at putting a M116 into my 280S but I want to put a carb on it to keep it simple.
Anyone done this? Anyone know of someone that makes an inlet manifold to suit? I know it's not a common conversion but hoping I won't have to reinvent the wheel...
Seen someone make their own manifold on youtube but my fabrication skills don't go that far.

I've managed to pick up a complete 350SEL for parts so I have all the mounts, radiator etc.

[daantjie]

Anything is possible with enough time and money

[ramiro]

Does the 350sel run and has K jetronic? If yes you could keep the injection system you just need to wire the fuel pump relay and add the fuel pump set, for wiring the engine harness only needs a wire from to fuel pump relay output to the warmup regulator and a starter signal for the cold start valve , i would say that it should be much easier then modifying the intake manifold.

Mechanical putting the engine in should same as putting a 280 back in , there is nothing special you just have to change the exhaust and the driveshaft.

[Nabstud]

Cheers. It's a 1975 350SEL with Djet so I think I'm out of luck going that route.

[ramiro]

Personally i would transfer the d jetronic system but if you are afraid of wires that would be a bad job , the engine harnes on d jetronic cars is seperate so you could remove it with ecu and add it to the 280s , the problem is that some wires go to the fuse box because there are 3 relays for the injection (pump , main power , cold start valve) .

Offcourse if the 350sel is not running it would be even harder.
Actually with the d jetronic manifold you could quite easily also use a aftermarket ecu but then you must know how to tune your engine.

[Nabstud]

It currently only runs when fuel is put straight into the inlet manifold. It did run for about a minute on its own, not 100% if that was just on the fuel I poured in or the D-jet was doing something. Fuel pump primes for a second each time the ignition is turned on which is a bonus! Been sitting for almost 10 years so fuel system probably needs a full going over.

[ramiro]

Ok , then you have to decide for yourself if you want to fight with d jetronic if you have some basic eletronic knowledge it could be easier and cheaper then getting a k jetronic running.
I have reactivated serveral k and d jetronic cars that sat for long and usually k jetronic needs a fuel distributor and warmup regulator overhaul and D jetronic needed some taps on the injectors and some pulses with 12v to get them unstuck and the car ran.

[Nabstud]

I had a bit of a play with it. New cheapy fuel filter, replaced a few fuel lines and it runs! Well it idles and revs well considering it has sat for many years.

[ramiro]

Then you could transplant the engine harness with ecu and fuel pump assembly and use the d jetronic i think it would still be easier than building an intake manifold and calibrating the carburator.
The main problem with d jetronic when in use can be the mechanical point contacts for the injection in the distributor, the rest is pretty reliable i would say.

[Nabstud]

Yeah the trigger points are one of my worries, I believe they are N/A.

[Nabstud]

I've decided to not go ahead with this conversion. If it was a 4.5 I probably would have given it a go, not that I'm after a sports car but seems the only benefit I would get would be the V8 sound and the challenge of the conversion.

I'm parting out this car now, see For Sale section.

[celberg]

350SEL is the rarest of them all. Not saveable?

[Nabstud]

Too far gone, rust is in every corner, boot floor, rear window, C pillar, even had rust bubbles in the middle of the bonnet...