Pistons
Due to the change of the piston capacity from 2.2 litres in the case of the DOHC petrol engine Z 22 SE to 2.0 litres, the Z 20 NET DOHC Turbo petrol engine features modified pistons, con-rods and a modified crank mechanism.
The pistons are zinc-coated and the piston bolts hardened by nitriding. An arrow on the piston base indicates the installation position (arrow pointing to the camshaft drive side).
The pistons are cooled from below using oil that is injected through a duct in the lower part of the cylinder block.
Dimensions and tolerances:
| R | Ø | A | H | B | D 1 | H D1 | |
|---|---|---|---|---|---|---|---|
| mm | 30 | 85.961-85.979 | 5.36 | 53.0 | 5.6 | 49.13 | 55.36 |
Con-Rods
Dimensions and tolerances:
| Diameter on crankshaft side | 52.118 - 52.134 mm |
|---|---|
| Diameter of piston bolt aperture | 23.012 - 23.017 mm |
| Maximum weight differential between the big ends of the con-rods | 8g |
| Length between the middle of the piston bolt aperture and the middle of the crankshaft side diameter. | 145.5 mm |
Crankshaft
Dimensions and tolerances:
| Length | 495.9 ± 0.25 mm |
|---|---|
| Main bearing play | 0.031 - 0.067mm |
| Diameter of crank pins | 49.000 - 49.014 mm |
| Con-rod bearing - play | 0.029 - 0.073 mm |
| Crankshaft - axial play | 0.040 - 0.372 mm |