DS21 & DS21M / DS19A & DS19MA Repair Manual — Page 56

June 1966. Corrective No.1 12, Prepare the assemblies of connecting rods - pistons - barrels. a) The assemblies of barrels and pistons are sold as are the pistons and gudgeon pins, - the position of the barrel in relation to the piston is not important with brand-new components, - there are two types of barrel corresponding to two classes of cylinder blocks. The groups are marked with a figure. The barrels are marked: - Class 1: one ring, Class 2: two rings on the upper portion of the flange. To avoid errors we advise checking the relationship of the barrel top face to the face of the cylinder block.