Originally Posted by HDDP
Yeah, the engine design is the same, just two added cylinders... Even the crossflow intake looks identical... I don't think you'll be able to just bolt-up anything... I would guess that you'll have to "shoe-horn" that engine into the bay, relocate the engine mounts on the frame and shim the engine to align it with your tranny... I'm concerned that you'll not have enough lenth in that engine bay... You may have to cut the firewall to make clearance for the throttle body...
Speaking of the tranny, have you verified that the bell housing is the same size, design and bolt patterns ? Even if it is... Since the engine is much longer than the V6 how are you going to get the engine to align longitudinally when you have no room to move the engine forward...
Just my humble opinion, and I might be wrong, but I think you're going to have to do a serious rebuild on the front end of the car to get that thing in there... First thing I would do before you even un-pack that engine is start making some comparison measurements... If you need me to give you the measurements of the V6 bell housing and distance of the motor mounts, I can do that fairly easily since my SRT engine is sitting on the engine stand...
There is actually plenty of room lengthwise (side to side is not an issue) Keep in mind that Mercedes puts four cylinder engines in the R170 chassis and that engine is the same length as a V8. Mercedes also puts V8's into very similar chassis. The only differrence I have found in the case of the four banger and V8's is that a very slim electric fan is used.
The automatic trans is the same one they also put behind V8's. I have verified that the bellhousing has the same basic bolt pattern but have not verified 100% that it is the exact same size. The Mercedes Tech that is helping me with the programming claims it will bolt right up. It will be nice if it does.
There won't be any cutting needed to the firewall. The rear of the engine will sit in the car exactly as the V6 does with everything including the throttle body in the same position. I have looked at a couple of Mercedes cars with both the 320 and 500 engines and they chissis's are the same as far as motor mounts go, so I am hopeful I can use OEM parts to bolt it in. If not, not a big deal, this is the type of work I am very used to. When my engine get here next week I may ask you for a couple of bellhousing measurements if you don't mind. I was planning on putting my car up on stands and taking more measurements as soon as I have the new engine to compare to.