If using Truck engine to mount into a car, first problem..
weight. The car chassis may just break up. If I not wrong, a bus
engine weights 8 times more than a normal sedan. Eg. car=180kg,
Bus=1.1 tonn.
Desiel engine are meant for power, not speed. They got the power to
drag weights, even if theres no weight for it to drag, you still
will not find it running fast.
If using truck engine, can you imagine the wear and tear it has on
the car?? How long the car will last sia??