Engine valve actuation system and lifter arm assembly having lifter arm oil spray port for cam-roller lubrication

An engine valve actuation system includes a rotatable camshaft having a cam lobe, and a lifter arm assembly having a lifter arm with a roller in contact with the cam lobe. A bushing is positioned in a pin bore of the lifter arm and journals the lifter arm upon the pin for reciprocation in response to rotation of the camshaft. An incoming oil passage extends to the pin bore, and an outgoing oil passage extends from the pin bore. The outgoing oil passage forms an oil spray port defining an oil spray path oriented to direct a spray of oil at the roller and/or the cam lobe. An oil feed groove is formed in at least one of the lifter arm or the bushing and fluidly connects the incoming oil passage to the outgoing oil passage.