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3
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Spiral joint oil control
4
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Ring gap lower compression
5
Upper compression ring
6
Lower compression ring
7
Oil control ring
All pistons are common single grade/single part number for all engines.
The piston top ring is a taper type and is fitted with a taper to the top of the piston. All rings marked 'top' are assembled with top to uppermost. All rings must be spaced evenly around the piston before installing. The circumference gap of the double bevelled oil control ring must be opposite to the spiral control joint.
Piston bowl volume is 20.025cc and the compression ratio is 17.3:1. Cylinder Heads and Valve Gear The cylinder head is of high quality aluminium and cannot be reworked. The cylinder head is secured to the engine block by eight bolts.
The cylinder head incorporates four valves per cylinder, glow plugs and a knock sensor. A vertically centrally placed fuel injector guarantees maximum distribution of fuel into the combustion chamber.
The cylinder head gasket is a three layer laminated steel construction that has an excellent service life and sealing properties. The cylinder head gasket is available in five different thicknesses depending on the piston protrusion height. The cylinder head gaskets are identified by serrations cut into the front end of the gasket.
The valves are operated directly by steel roller rockers with hydraulic lash adjusters. |