Mercruiser 7.4 engines are on the large end of the Mercruiser engine line. Mercruiser engines are made for the marine market by Mercury Marine. The 7.4L models are the 7.4 MPI and the 454 Mag MPI.


Mercruiser 7.4 engines are V-8 and have a displacement of 7.4 liters. Maximum revolutions per minute is 4,200 to 4,600 rpm. Idle rate is 600 rpm in neutral. The eight cylinders fire in a 1-8-4-3-6-5-7-2 sequence. The 7.4 multiport injection model has 310 propshaft hp and 231 propshaft kilowatts. The 454 Mag multiport injection model has 385 propshaft hp and 287 propshaft kilowatts.