sdgold@att.net

As a retired Star Sales Consultant, and Lifetime Tech, I have toyed with the thought of transplanting an S65 powerplant into my R63… I believe it would rival supercharging the 6.3 V8 in every way, and be far more efficient over the long haul… interestingly, one can purchase a S65 complete car for less than the cost of supercharging the 6.3; when swap is accomplished - the 6.3 could be implanted in the S and you’d have two complete autos!!! Thoughts anyone???

1955W196S

It would be interesting to see how it turned out. However, if you buy a complete S65, you would already have two compete autos without changing the motors. It seems to me that it would destroy the collectible value of both vehicles. Of course, you could always change the motors back, but somehow, I don't think this is a half hour job.

sdgold@att.net

The idea wasn’t to swap engines back later, the idea was to increase the performance of the already ridiculous level of the R 63!!! I would put the 6.3 in the S and resell it with the “more reliable” V8 rather than the V12… Having forty five years I. The business, I would sell the V8 powered S for enough to cover its original cost, plus the cost for the swap… imagine - a twin turbo 6.0L V12 powered R - Class… what a machine!!!

1955W196S

How do the sizes of the two motors compare? In other words, is there room for the V12 in the R63? If you do this, I would love to see photos and periodic videos.

sdgold@att.net

The first R classes had the inline six, so there should well be room for the 12

zedmikey

I definitely dig the idea of a turbo V12 R-class, but I'm with 1955W196S on this one. I wouldn't want to hack up two AMGs to make it happen.

I've thought about this, too, but my thought was to start with an S600 and an R350. Pull the M275, rebuild it as mild or wild as desired, shoehorn it into a stripped R350 chassis, and pin that throttle as often as possible. I think this route has better smiles per dollar.

focalxplosion

I love the idea of a V12 R65, but it's going to take a lot of custom fabrication and thoughtful upgrades to make it happen.

The R class was only ever offered with a V6 or V8. https://en.wikipedia.org/wiki/Mercedes-Benz_R-Class

There isn't enough clearance to the back of the radiator for the longer V12 engine. I'm assuming you would choose the M275 of the same era as the R Class but I believe all V12's since 1998 have the same overall length. The radiator will need to be relocated to clear the accessory belts.

You'll also need to consider that the M275 was never paired with 4Matic and retained the more robust 5-speed transmission. Perhaps you can upgrade the 7G transmission to survive the extra torque but this decision can't be ignored.