Morgan is/was a separate manufacturer from Morris Garages, Triumph, Austin, et al. Initially Morgan started as a three wheel automobile. It had two front wheels and one rear. It used an air cooled V twin mounted between the front wheels with its crankshaft longitudinal. The frames were made of oak. The first four wheel motorcars still had oak frames. I do not know what four banger was sourced for use in the +4. Eventually they negotiated purchase of the Buick/Olds designed Aluminium 3.5L V8 for the +8 model. By this time they had steel frames. I may be wrong but I think Morgan may still be in limited production. The Rover V8 is out of production now. Rover has used Ford and BMW engines since.