Roger Clark Motorsport Cylinder 4 Cooling Mod KitNote.: Gloss Black kit shown. Cylinder 4 cooling has long been a known issue on the EJ Family of Subaru engines. The nature of the water passageways around this area means a lack of cooling can lead to an increase in the temperatures around this cylinder. RCM's simple solution to this problem lies in our easy to fit complete kit. Billet fittings are banded in place on our custom 90 degree Samco silicon hose, which you simply fit into the unused port