An engine variable valve actuation mechanism that substantially equally
adjusts the valve lift amount in each cylinder. The mechanism includes
variable valve lift mechanisms respectively arranged in association with
the engine cylinders. A control shaft extends through the variable valve
lift mechanisms. An actuator moves the control shaft in the axial
direction and drives the variable valve lift mechanisms. Collars are
arranged alternately with the variable valve lift mechanisms. Each collar
includes a cylindrical sleeve and flanges formed integrally with the
sleeve. The flanges directly or indirectly contact the end faces of
adjacent variable valve lift mechanisms. This determines the positions of
the variable valve lift mechanisms with respect to one another in the
axial direction.