Volvo Penta MD30A (B),(D), AQ30A (B),(D), TAMD30A (B),(D), TMD30A (B),(D),

Four-cylinder, four-stroke marine diesel engine of swirl chamber type. Output* 48 kW (65 hp). A compact 2.39 litre diesel engine of the swirl chamber type. Its high torque, together with the Volvo Penta MS2B or MS2V reverse gear, gives excellent thrust even at low speed and thus good boat handling.

see here for marine diesel engine parts - Boulters Chandlery