Originally Posted by Admiral Ahani

I have a w114 in my shop right now with the engine removed, because we were planning to put a v8 in it. And right next to it is the M117 5.6L engine. I can tell you that the engine will not fit in the engine bay, unless you make custom headers with about 1.5" pipe diameter, and extremely tight bends, and they might still rub the frame rails.

It can be done, if we were willing to cut sheet metal, but this car is extremely nice and we wanted to leave the body/frame original, so we aborted. Even with hacking the metal it would have been tight. We considered an M116 because it's narrower, but it would still need custom headers. Mind you, custom headers means small pipes with tight bends, which means low performance, and the M116s aren't very powerful anyway, so it became pointless. Then we considered the M113, but even those are too wide for the W114, so same problem. Before you ask, the M119 is wider than them all.

The W114 can really only take inline engines or pushrod V8s unless you want to modify the frame. I'm happy to share my measurements if you're interested.

For our car, we decided to keep the stock M110, go with euro cams and headers, TBI, and MS for a start and perhaps more in the future. We probably won't be satisfied with the power but it will be a good start. If you're not a purist, I'd recommend the ford v8. I'm not a total purist, but I wanted to stick with a Mercedes engine with this W114 as well as my other projects.