Why are transversely mounted engines for front wheel drive cars not suitable to fit in rear wheel drive cars?

Answer 1

Since transverse engines turn paralell to the axel, they need to connect to the transmisison/differential with either direct meshing gears or a chain drive (rather than a driveshaft and 90 degree angle gearset).  This only works well when the engine and drive wheels are at the same end of the car because a chain drive going all the way from one end of the car to the other is impractical.  There are also mid/rear engine cars with rear wheel drive with transverse mounted engines.