Checking, Facing Cylinder Head Contact Surface

Checking, Facing Cylinder Head Contact Surface






1 Remove valves
2 Inspect flatness of cylinder head in longitudinal direction
3 Measure height of cylinder head (inspection dimension H) and note
4 Machine cylinder head contact surface

NOTE: Only machine cylinder head contact surface if porous or damaged points are present, or if an impermissible variation of the flatness in the longitudinal direction is measured.

- The stock removal of the cylinder head and the crankcase of an engine must together be not more than 0.4 mm.

NOTE: The top cylinder head contact surface must not be machined otherwise the basic bores of the camshaft bearings will be altered.

- If cracks are suspected (internal loss of coolant), pressure-test cylinder head.

5 Once again measure height of cylinder head (inspection dimension (H))
6 Insert valves (42, 43).
7 Measure inspection dimension (T) between end of valve stem and base of camshaft bearing and note

NOTE: To do this, insert dia. 0.6 mm round material centered into the camshaft bearing base and measure dimension (T) with sliding caliper.

CAUTION: If measurement is less than dimension (T) no further correct valve clearance compensation is possible; replace valve seat ring or cylinder head.

8 Re-work valve seats to match stock removal at cylinder head
9 Install in the reverse order.