IT'S A MATTER OF HILLS AND VALLEYS Available to Purchase

THE present generation of automotive diesel engines is designed with parent cylinder bores, or liners, requiring bore sizing after initial fitment. At overhaul this permits reboring and fitment of oversize pistons. A cylinder surface finish controlled to 25—40 micro inch CLA with a cross hatch angle of 120° is then required to give optimum conditions for ring bedding, vital for gas seal and oil control. (Fig 1 shows the correct cross hatch angle).