Originally Posted by: myleftnutt13 
Originally Posted by: ManteoMax 
I don't know how Turn 10 decides on engine swaps for each car. Maybe it's for PI balancing purposes, maybe it's something about fitment.
Technically you can put any modern engine in any car. It may not be practical but it is possible. Hell you could TECHNICALLY put a v12 in a smart car if you so desired.
Would it fit and package without having to make some serious alterations to the car? Sure, a V12 but are we talking your typical V12 or a super tiny, miniature, low displacement V12?
So, I did some looking up just to see what we;re dealing with here:
Here are the exterior dimensions of the
2013 Smart ForTwo:
Wheelbase: 73.5"
Rear Track Width: 54.5" <-- engine sits in back
Height: 60.7"
Length: 106.1"
Base Curb Weight: 1808 lbs
You should also note that the engine in the car is transverse mounted and not longitudinal. Any engine swap would best go in that way as well to prevent major changes or modifications to the passenger compartment. Also, the rear tire size on wheel (not rim size, the whole thing) 15" and as seen
here is about the entire length of the engine bay.
Now let's look at some V12 engines. Here is the
GM 702ci V12:
Width: 21" outside valve cover to outside valve cover
Height: 36" bottom of oil pan to top of carb
Length: 53" front of mandrel pulley to rear of transmission adapter (no transmission)
Weight: 1405 lbs wet
Another V12 we can look at is the M120 Mercedes Benz V12 which,
according to owner measurements, measures in at:
Base Width: 20"
Top Width: 26.8"
Height: 25.6"
Length: 33.1"
Weight: 527 lbs
As we can see, the weight of the first engine alone could pose a problem for the car, but looking further there may not be much room in the crs engine compartment to fit these engines without serious alterations. I, personally, also think it's not a very god idea and I don't know why you'd want to have a V12 in a Smart car. People do not typically cross shop the V12 segment and the Smart car segment for one, and for two there is a very good smart car build that is easy to do and readily available from
Smartuki. For the car, it makes a lot more sense than a V12 anyway.
Some engine swaps can be done with not many major changes, some require some fitment work, and sometimes, the engine bay may just not be big enough to house all the needed components to do the swap.