Grinding Cylinder Head Mating Surface

Grinding Cylinder Head Mating Surface

Checking Cylinder Head for Distortion

Check mating surface of cylinder head for distortion with a feeler gauge blade and straightedge.

Permissible distortion of mating surface: 0.05 mm.
Cylinder heads with a distorted sealing surface can be resurfaced by grinding.
Permissible distortion after machining: 0.03 mm.

Grinding Cylinder Head

Only machine the sealing surface of a cylinder head enough to reach a level surface.
Wear limit: 23.6 mm

Sealing surface machining note:
Peak-to-valley 0.015 mm

If the new-dimension tolerance is exceeded during machining, a cylinder head gasket with a thickness of 1.4 mm must be fitted.

New distance A = 24 ± 0.1 mm
Wear limit distance A = 23.6 mm






Note:
- When refacing the sealing surface on the combustion chamber side, always check the sealing surface on the camshaft side as well and reface if necessary.
- Admissible distortion of the camshaft sealing surface:
When checking: 0.1 mm
after refacing : 0.03 mm
- Before machining the sealing surface to the camshaft housing, check dimension "A" to avoid unnecessary work.
- Before machining, plug the oil passage of the return valve. Remove cylindrical pins.

Cylinder head refacing dimension and Identification

New dimension : 24 ± 0.1 mm
Gasket : 1.1 mm
Identification : none

Refacting dimension : 23.8 to 23.6 mm
Gasket : 1.4 mm
Identification : N

Identification "N"
To be embossed on cylinders No.1 and 4.

Punch character height "N" = 10 mm