Subaru’s EJ20G was a turbocharged, 2. Specifications for other markets may differ. The EJ20G engine had a die-cast aluminium alloy postre peruano block with 92.
0 mm bores and a 75. 0 mm stroke for a capacity of 1994 cc. The cylinder block had an open-deck design to enhance cooling efficiency and dry-type, cast iron cylinder liners. For the EJ20G engine, the crankshaft was supported by five bearings that were made from aluminium alloy, while the no. 3 thrust bearing had a metal flange to receive thrust force. Furthermore, the corners of the crankshaft journals and webs, and the crank pins and webs, had a fillet-roll finish to increase stiffness.
GM Impreza WRX, the EJ20G engine had cast pistons and connecting rods. The piston head was recessed for both the intake and exhaust valves, while the pistons had three rings: two pressure rings and an oil control ring. The oil control ring had a slit design. Furthermore, the piston pin was located in an offset position. A single timing belt was used to drive the four camshafts, while the back of the belt also drove the water pump. The timing belt consisted of a strong and inflexible core wire, wear-resistant canvas and heat-resistant rubber material. For quiet operation, the teeth on the timing belt had a round profile.
Each camshaft was supported by three journals with three camshaft caps, while each camshaft flange was supported by a groove in the cylinder head to receive thrust force. The EJ20G engine had four valves per cylinder that were actuated by hydraulic lifters. 20,000 rpm to 150,000 rpm and peak boost is understood to be around 11 to 12 psi. To prevent excessive boost pressure, which could cause knocking and heavier thermal loads on the pistons, the EJ20G engine had a wastegate valve. Once boost pressure reached its maximum, the wastegate valve would open so that part of the exhaust gas would bypass the turbine and flow into the exhaust pipe. The turbocharger was lubricated by the engine oil and used full-floating type bearings to form lubrication films.
After cooling the bearing housing, the coolant flowed into the coolant filler tank via a pipe. The EJ20G engine had an air bypass valve to prevent the suction noise that can otherwise occur when the throttle valve is suddenly closed and causes a sudden rise in air pressure between the turbocharger and the throttle body. The air bypass valve was actuated by the vacuum created by the closure of the throttle valve and allowed the suction air to bypass the turbocharger and flow upstream, thereby lowering the pressure in the air passage. Since the turbocharging process increased the temperature of the intake air, it was then passed through an air-cooled intercooler that received air via the bonnet duct. The intercooler was mounted on top of the engine and cooled the intake air to increase its density. GM Impreza WRX, the EJ20G engine used a hot-film type mass air flow sensor to calculate intake air volume.