Examining Contact Surface of Cylinder Head

1. Remove valves.
2. Measure and note reference size (H).
3. Re-face cylinder head contact surface, if necessary.

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

NOTE:
^ Only machine cylinder head contact surface if porous or damaged points are present or if an impermissible deviation from the evenness in the longitudinal direction is determined.
^ If cracking is suspected (internal loss of coolant), the cylinder head must be pressure-tested.

4. Deburr sharp edges on edge of combustion chamber.
5. Once again measure the reference size (H). Determine stock removal.
6. Insert valves (42) and (43).
7. Measure reference sizes (T) between end of valve stem and camshaft bearing base. To do this, insert a 6 mm diameter bar centered into the base of the camshaft bearing and measure size (T) with caliper gauge.

CAUTION: If size measured is less than size correct valve clearance compensation is no longer possible; replace valve seat ring or cylinder head if necessary.

8. Machine valve seats according to cylinder head stock removal procedure.

Specifications
Total Height H Of Cylinder Head: 135.90 - 136.00 mm
Minimum Height After Machining: 135.50 mm

CAUTION: The stock removal of the cylinder head and the crankcase of the engine must together be not more than 0.40 mm.

Permissible Deviation Of parallelism of top-to-bottom contact surface of crankcase in longitudinal direction: 0.10 mm
Permissible Deviation Of Evenness Of Contact Surface:
Longitudinally: 0.08 mm
Transversely: 0.00 mm
Surface Finish Peak-To-Valley Height: 0.003 - 0.010 mm
Reference Dimension T:
Standard Size:
Inlet: 24.21 - 24.75 mm
Exhaust: 22.21 - 22.75 mm
Repair Size:
Inlet: 23.96 - 24.51 mm
Exhaust: 21.96 - 22.51 mm