The SE series engines are the results of a 10 year programme of fundamental research into engine design to create a new generation of engines for the 21st century. Dorman engineers were given the brief to develop a completely new design based on inherent reliability, low fuel consumption, low exhaust emissions, improved serviceability, high power to weight ratio, low running costs, high commonality of parts and low price per unit of power output.
To achieve the brief, the latest in computer aided design techniques were applied to help create the new engines. Dorman engineers have concentrated on the central process of combustion, examining in detail how to achieve the greatest efficiency in fuel usage to produce high power in a compact engine.
Central to the SE concept is a unique piston and cylinder design which incorporates a unit fuel injector. All SE series engines benefit from this proven Dorman design concept. These individual cam/rocker operated unit injectors achieve high pressures to ensure ultra-fine fuel atomisation, and hence, controlled rapid combustion resulting in low smoke and gaseous emissions, whilst producing high powers per cylinder. The application of unit injection eliminates the need for external high pressure fuel pipes.
The pistons are aluminium alloy and incorporate gallery cooling thus ensuring a thermally stable piston throughout the load and speed range. This feature gives longer life of piston-rings and cylinder liners, whilst decreasing the risk of potentially harmful carbon deposits. The upper ring is wedge shaped running in a Ni-resist iron carrier, thus eliminating top ring groove wear and ring sticking after the extended periods of running at excess powers.
The SE cylinder and injection system are common throughout the SE series allowing these engines to achieve the highest power outputs per litre of cylinder capacity.
All SE series engines have externally mounted large capacity oil pumps to supply cool pressurised oil to all working surfaces of the engine in addition to the piston cooling jets. Wedge shaped gudgeon pin bosses create large bearing areas, thus enabling high power to be transmitted to robust induction hardened crankshafts.
Each cylinder has an individual four valve head to give optimised gas flows to these high specific power engines. Both inlet and exhaust valves are made from 21-4N valve steel with a Stellite facing, chrome flashed stems, and Stellite faced tips. The renewable valve inserts are made from Brico 52. This combination of valve and valve seat being selected to give extended durability.