Institute Of Infectious Disease and Molecular Medicine Exploiting the uniqueness of the soloMERTM technology for the development of next-generation, super-potent drug modalities for chronic autoimmune inflammation diseases, and beyond - Subaru FA20D Engine - australiancarews The FA20D engine had an aluminium alloy cylinder head with chain-driven double overhead camshafts. The four valves per cylinder – two intake and two exhaust – were actuated by roller rocker arms which had built-in needle bearings that reduced the friction that occurred between the camshafts and the roller rocker arms (which actuated the valves).