EJ251 and EJ252 Subaru Engines
Table of Content Cylinder head Block and crankcase Injection and ignition Injection and ignition Cylinder head Block and crankcase Relative to their EJ Phase I predecessors, the pistons for the EJ251 and EJ252 engines had reduced piston pin offset and a molybdenum coating to reduce friction. Other features of the pistons included solid-type piston skirts, flat top combustion surfaces and reduced top land to cylinder clearance. The Subaru EJ251 and EJ252 engines had an aluminium alloy block with 99.5 mm bores – with cast iron dry-type cylinder liners – and a 79.0 mm stroke for a capacity of 2457 cc. The cylinder block for the EJ251 and EJ252 engines had an open-deck design whereby the cylinder walls were supported at the three and nine o’clock positions. Due to the cylinder head offset, the left camshaft was longer than the right camshaft to align the cam belt sprockets. Both camshafts were driven by a single belt which had round profile teeth for quiet operation and was const...