Cylinder Head Identification; Engine Rotation - Mercury MerCruiser MCM 454 Mag MPI Service Manual

Table of Contents

SERVICE MANUAL NUMBER 23

Cylinder Head Identification

Cylinder heads are identified by their smaller and rounded intake ports.

454 MAG MPI / 502 MAG MPI / 8.2L MPI

Cylinder heads are identified by their large rectangular intake ports.

Engine rotation terminology at times has caused confusion. To clarify, engine rotation is

determined by observing flywheel rotation from the rear (transmission or stern drive end)

of the engine looking forward (water pump end).

PROPELLER ROTATION IS NOT NECESSARILY THE SAME as engine rotation.

When ordering replacement engines, short blocks or parts for engines, be certain to check

engine rotation. Do not rely on propeller rotation in determining engine rotation.

90-861326--1 MARCH 1999

Downloaded from

https://needmanual.com/

Left-Hand Rotation (CCW) - All Sterndrive (MCM) Engines And Inboard (MIE)

(Standard) Rotation

454 CID (7.4L) / 502 CID (8.2L)

Table of Contents