Pistons And Cylinder Bore, Checking

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-- Measure approximately 15 mm from the lower edge at a 90° angle to the piston pin axis using a 75 to 100 mm external micrometer.

		Piston Diameter
Basic dimension	mm	82.465 ¹⁾
¹⁾ Measurements without graphite coating (thickness = 0.02 mm). The graphite coating wears off.

Fig 1: Piston Ring Gap

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-- Push piston ring squarely from above down to approximately 15 mm from bottom end of cylinder. To do this use a piston without rings.

Piston Ring Dimensions in mm	New	Wear Limit
Compression ring	0.20 to 0.40	0.80
Oil scraping ring	0.25 to 0.50	0.80

Fig 2: Piston Ring Groove Clearance

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-- Clean the ring groove of piston before checking.

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Special Tools And Workshop Equipment Required

CAUTION:

Do Not Bore, Hone, Grind Or Rework The Cylinder Bores With Workshop Tools. Reworking Damages The Surface Of The Cylinder Bore.

-- Using a :VAS6078 measure in a diagonal sequence at three positions transversely -A- and longitudinally -B-.

		Cylinder bore diameter
Basic dimension	mm	82.51

NOTE:

The cylinder bore must not be measured when the cylinder block is mounted on the :VAS6095 because the measurements may be incorrect.