The EJ208 engine had a die-cast aluminium alloy cylinder 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 (the outer surfaces of ‘dry type’ liners are in complete
contact with the cylinder walls).
Crankshaft, connecting rods and pistons
For the EJ208 engine, the crankshaft was supported by five bearings that
were made from aluminium alloy. For the EJ Phase II engines like the EJ208,
the crankshaft thrust bearing was relocated to the rear of the crankshaft
(previously the no. 3 bearing).
The EJ208 engine had cast connecting
rods and forged aluminium pistons which weighed 162 grams each. For the EJ
Phase II engines, friction reduction measures for the pistons included:
- Reduced piston pin offset;
- Solid type piston skirts;
- Molybdenum coating; and,
- Reduced top land to cylinder clearance.
The piston crowns for the EJ208 engine had flat tops for a compression
ratio of 9.0:1.
Cylinder head and valves
The EJ208 engine had a die-cast aluminium cylinder head with double overhead
camshafts (DOHC) per cylinder bank. A single timing belt was used to drive
the four camshafts – it 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.
recommended replacement interval for the cam belt was 100,000 kms or four
years, whichever occurred first. A self-adjusting, hydraulic tensioner
maintained timing belt tension and valve clearance checking/adjustment was
only necessary every 150,000 kms.
The EJ208 cylinder head had four
valves per cylinder that were actuated by solid valve lifters. The intake
valves had hollow stems to reduce mass and inertia, while the exhaust valve
stems were filled with sodium. At high temperatures, the sodium would
liquefy and its motion within the stem would effectively transfer heat from
the valve head to the valve stem, contributing to faster cooling of the
valve head. The intake valves weighed 48.4 grams each, while the exhaust
valves weighed 46.7 grams each.
The EJ208 engine had two sequential turbochargers – a primary IHI VF33
turbocharger and a secondary IHI VF32 turbocharger – which operated in three
- Primary stage single turbo operation: at low to medium engine
speeds, boost pressure was provided solely by the smaller, ‘primary’
turbocharger. The boost pressure generated by the primary turbocharger
was controlled by a wastegate which operated in response to signals from
- Intermediate preparatory stage: at medium engine speeds, the exhaust
control valve was partially opened – in response to signals from the ECM
– so that the secondary turbocharger would begin to rotate. Initially,
pressure generated by the secondary turbocharger was redirected to the
inlet side of the air intake. Furthermore, the ECM uses a differential
pressure sensor to measure the difference in boost pressure between the
intake manifold (generated by the primary turbocharger) and the
secondary turbocharger; and,
- Secondary stage twin turbo operation: when the ECM determined that
engine operating conditions were suitable, the relief valve would close
and the exhaust gas control valve would fully open. When the intake
control valve was opened, pressure from the secondary turbocharger was
supplied to the intercooler. During this stage, boost pressure control
was regulated via the primary turbocharger’s wastegate.