1999 Volvo Penta "WT" Models Workshop Manual, Page 173Get this manual
Valve Train The valve train is ball pivot typeMotion is transmitted from the camshaft through hydraulic roller valve lifters and tubular valve push rods to the valve rocker armsThe valve rocker arm pivots on ball to open the valveThe hydraulic roller valve lifters keep all parts of the valve train in constant contactThe valve rocker arm ball is retained on the valve rocker arm stud with locking nutThe valve rocker arm studs are pressed into the cylinder head
Intake Manifold
The intake manifold is single piece designIt supports either throttle body or multiple injectors to meter and distribute fuel to each engine cylinder