Honed combustion cylinder

After a combustion cylinder has been bored, it is honed to retain the proper amount of lubricant on the cylinder wall during operation. This is done in part by controlling the cross hatch angle of the honing pattern. This is shown for a honed cylinder in Figure 1.


Figure 1. Cross hatch pattern of a honed cylinder



The red areas in the top and bottom of the image of Figure 1 indicate reversals of the axial velocity of the honing stones. The number of bright red areas indicates the number of honing stones in the tool. The cross hatch angle has been calculated from the data and is indicated at various locations on the image.


 
Figure 2. Improperly honed combustion cylinder


Figure 2 shows an image of another honed cylinder. In this cylinder the pressure on the honing stones does not appear to be uniform across the stones and the honing pattern in the top part of the cylinder is different than in the bottom half. The axial reversal of the honing stones from the top and bottom reversals combine in the middle of the cylinder.



Other surface finish defects can be detected in images of the cylinder surface. Figure 3 is a scanned image of a honed cylinder showing swipe marks that can occur when honing stones are not fully retracted when a honing tool is removed from a cylinder.

Figure 3. Honed cylinder showing swipe marks from retraction of the honing stones