Cylinder Block Assembly: Description and Operation

LEGEND
- 1 Cylinder liner
- 2 Piston
- 3 Wrist pin
- 4 Sodium cooled exhaust
- 5 Camshafts
- 6 Intake passage
- 7 Piston cooling nozzle
- 8 Piston cooling nozzle valve cover

CYLINDER BLOCK
The cylinder block has been modified as follows:
- The cylinder diameter has been reduced (from 83 to 81 mm) to increase the thickness of cylinder liners (1).
- The reinforced pistons (2) have smaller diameters and have a more concave crown to reduce the compression ratio. The bottom of the piston skirt has a cut out for a piston cooling nozzle.
- Gudgeon pins (3) have been reinforced with a reduced center hole.
- Exhaust valves (4) are sodium cooled to withstand high temperatures.
- Camshaft (5) lift is lower. This improves idling and comfort without affecting output.
- Intake passages (6) have been modified as there is no variable-flow intake manifold.
- There are openings in the cylinder block for the piston nozzles (7) and relief valves. These are housed inside three covers on the outside of the block (8).

The special spark plugs can withstand very high temperature and pressure while retaining the old service interval.
The crankshaft and thrust bearing have been modified to meet the higher loads on the crank mechanism in a turbocharged engine. These modifications also affect other five and six cylinder engines:
- The grooves in the lower bearing halves have been eliminated, raising engine oil pressure and creating a better oil film.
- The material used in the big end bearings has been improved. The lead-bronze alloy has been replaced with a more heat resistant aluminium alloy.