Piston, Engine

Pistons

Piston Replacement Notes:
- Later B6304 engines have two types of pistons, which differ in terms of their upper compression rings.
- Version 1 can be replaced by version 2 without having to replace all pistons.
- Version 2 must not be replaced by version 1.






A = Overall piston height.
B = Height from wrist pin center to crown.
C = Measure piston diameter at right-angles to wrist pin hole at distance "C" from edge of skirt.
D = Piston diameter.

Dimensions A, B and C.
Dimension A: 59.9 mm
Dimension B: 35.9 mm
Dimension C: 16.0 mm

Standard piston diameters:
Piston marked C: 82.98-82.99 mm
Piston marked D: 82.99 33.00 mm
Piston marked E: 83.00 83.01 mm
Piston marked G: 83.017-83.032 mm

Oversize pistion diameter:
Oversize 1: 83.177-83.192 mm
Oversize 2: 83.377-83.392 mm

Piston weight: 360 ± 5 grams
Max. difference in weight between pistons in same engine: 10 grams.





Piston clearance:

Example:

Measured cylinder diameter - 96.03 mm
minus
Measured piston diameter - 96.00 mm
equals
Piston clearance - 0.03 mm

96.03 - 96.00 = 0.03

Piston clearance should be: 0.01-0.03 mm (max)

Piston ring side play:
Upper compression ring: 0.05-0.085 mm
Lower compression ring: 0.03-0.065 mm
Oil scraper ring: 0.02-0.055 mm

Piston ring dimensions, version 1 (1992-93)
Upper compression ring: 1.5 mm
Lower compression ring: 1.75 mm
Oil scraper ring: 3.0 mm

Piston ring dimensions, version 2 (1994-98)
Upper compression ring: 1.2 mm
Lower compression ring: 1.75 mm
Oil scraper ring: 3.0 mm

Wrist Pin diameter: 23.0 mm