This is a - already somewhat outdated - cylinder block and cylinder head treatment machine with which, e.g., a cylinder head on the cylinder side, becomes absolutely level again. Unevenness comes about by inadmissible overheating, e.g., if the cooling system breaks down. In this case it contorts, must be demounted and be clamped solidly onto the machine bed. If the right distance is adjusted with the help of the hand wheel, the whole arm turns slowly clockwise after switching on. At the same time a segment disc rotates for cast iron, and a knife head is being used for aluminium.
The correct clamping and the levelling of cylinder heads with swirl chambers is problematic. They stand out, e.g., 1/10 mm as a preliminary tension during the cylinder head assembly. After the levelling the correct preliminary tension is gone. In any case, the height of the material decrease has to be considered when you select the cylinder head gasket. You should consider that this kind of repair is just possible with a cylinder head that is not too much out of shape. The compression ratio in the single cylinders should possibly be approaching equality. If the cylinder head gasket is too far gone, a new one is required.
The evenness of a surface can be checked with the crack of light method. You superimpose a straight-edge over the surface and depending on the width of the crack of light you can draw conclusions on the size of the unevenness. In addition, you can use a feeler gauge. 06/08