Engine installation systems and related methods. An engine installation system includes an adapter cradle and a transport dolly. The adapter cradle is configured to support the engine, and the transport dolly is configured to be selectively and operatively coupled to the adapter cradle to support the adapter cradle to facilitate transporting the adapter cradle and the engine across a ground surface. The adapter cradle is configured to be selectively coupled to each of the transport dolly and the vehicle. The adapter cradle is configured to pivot relative to the transport dolly or relative to the vehicle to transition between a transport configuration and an upright configuration. In examples, methods of installing an engine within an engine bay of a vehicle include positioning the engine beneath the engine bay, pivoting the engine relative to the vehicle, and lifting the engine into the engine bay.