Engine Changes From B4204T20
Several engine changes are listed below that are introduced with the B4204T35 and B4204T28 engines.
Cylinder block
CISG (Crankshaft Integrated Starter Generator) is located between engine and gearbox. The engine block is modified at the rear with attachments for the stator and holes for cooling to CISG.
For more information on CISG, Refer to: DESIGN AND FUNCTION, .
Catalytic converter
The B4204T28 engine (USA) has a unique catalytic converter and a control system with three lambda probes. See Exhaust after-treatment. Refer to: DESIGN AND FUNCTION, .
The attachment bracket for the catalytic converter is slightly modified since the gearbox has changed position following the introduction of CISG.
The cooling pipe on the rear of the engine block is adjusted with pipes for cooling CISG.
Bracket, vacuum pump
There is a bracket on the front of the engine in the location where the alternator is fitted on the B4204T20 engine.
The A/C compressor on the Twin Engine is electrically-driven and the generator function is built into CISG, facilitating a simpler routing of the engine's auxiliaries belt.
The belt is equipped with a spring-loaded tensioner and an idler wheel. The service interval is 240 000 km.
Crankshaft sensor
The location of CISG between engine and gearbox has necessitated a change of position for the crankshaft sensor.
Main bearing
Due to forces from the CISG that propagate through the crankshaft, the main bearing cups in position 1 and 5 are coated with a polymer layer.
The polymer layer gives the surface stronger resistance to point loads and the rapid starts that the internal combustion engine in the hybrid concept has to withstand.
Information on the B4204T20 petrol engine can be found under DESIGN AND FUNCTION,