Which engines fit which cars ?

[bigben]

Hello,

Newbie to the forum (I introduced myself in general discussion) and I am keen to find out which engines might fit in my R107 300SL.

The obvious ones are

M116 4.2
M117 5.0 or 5.6 as the car was sold with these

I would have thought the M104 engine being based on the M103 block should also fit, anyone got any thoughts on that one.

Does the M113 engine (AMG 55 engine) have anything in common with the earlier 5.0 units ?

The reason for my interest is I am keen to upgrade the car with a more modern engine, ideally with more power. I know it would probably be cheaper to sell the car and just get one with a bigger engine but I am also looking for a project.

Thanks in advance for any help

Cheers

Ben

 

[Will]

Possibly an M104 with the associated electronics etc would be a sympathetic swap (as your car is presently a straight-six). a 3.2 would be the easiest/cheapest to find, however an AMG 3.6 would have a little more grunt (276bhp from memory). Could even fit a twin turbo set up (ala the TT kits sold by MB dealer Hughes of Beaconsfield?)

I have not looked at what's involved with fitting one of the later V8s into your car although I guess it wouldn't be impossible - pretty much anything is do-able with the right amount of time/money/determination etc.

I know you've already mentioned the option of selling your car to upgrade - but that's exactly what I'd do TBH. R107s aren't all that expensive and a 500 model would be a better long-term prospect IMHO.

Will

 

[owensmith]

The new m113 engines have 3 valves per cyllinder and I believe that the older units the one before are 4 valves per cyclinder there is alot of info on wiki but its hard to tell if its true or not!

 

[grober]

Will's advice on using a M104 is a good one. A big V8 will fit but as usual its the ancillaries that can prove problematic. You may need a better cooling system, different twin exhaust much more complex electrics e.g. combined injection/ignition system instead of discrete systems-- maybe one that will talk to the autotransmission which you may need to swop also. The twin cam headed V8 engines are a wider fit in the engine bay and will need different air intake/air cleaner units-- it all begins to add up. Some people would say a more modern more powerful V8 is a step too far for the R107 chassis which struggled a bit with the less powerful single cam v8's anyway.

 

[219]

I would go for the 3.0 version of the M104 if I was doing that , since the 2.8 and 3.2 versions have the distributorless ignition and HFM injection which are very different , involving a lot of messing about with electronics ; the 3 litre M104 , as used in various 300-24 models uses the same injection and ignition as your existing engine so would be a simple drop-in replacement - also has more or less the same output as the 3.2 ( 3.0 M104 = 231 bhp ) - the exhaust should also fit without modification .