Through the use of oil pressure and spring force, the lash adjuster maintained a constant zero valve clearance.
The iridium-tipped spark plug caps, which provided contact to the spark plugs, were integrated with the ignition coil assembly.
While the cylinder block had an open-deck design, Subaru claimed that lowering the water jacket achieved the same block stiffness as a semi-closed structure.
For the FA20E and FA20F engines, the volume of the catalytic converter was increased, while new air-fuel and oxygen sensors were introduced for greater accuracy in detecting gas concentration.
Furthermore, the coolant flow rate within the cylinder head was increased and improved cooling around the spark plugs and injectors raised the knock limit for more reliable performance..
Description: Specifications for other markets may vary.