RING-PISTON 7E2990 - Caterpillar

3204, 3208 Engines In All ApplicationsSUPPLEMENT: 04/25/83SERVICE MAGAZINE, FEBRUARY 14, 1983, PAGE 5.In the article "Check Cylinder Bores For Chamfer During Reconditioning", change the sixth sentence in the article to read "Grind the chamfer in the cylinder bore after final honing is done to the cylinder bore." Also, change the word "Housing" in Illustration 1 to read "Honing."
--------------- END SUPPLEMENT ---------------During engine reconditioning procedures, make sure that each cylinder has a small chamfer at the bottom of the bore. See Illustration 1. These engines have a chamfer when they are shipped from the factory. If the cylinders have been made larger or if sleeves have been installed in the cylinder block, the bottom of each bore must be given a chamfer of approximately 10° when reconditioning is done. This will remove any sharp edges and prevent piston damage during operation and possible piston seizure. Grind the chamfer in the cylinder bore before final honing is done to the cylinder bore. This will prevent a rough edge at the bottom of the bore. Use the 1P3565 Chamfering Group shown in Illustration 2 and the Reconditioning Section of the Service Manuals for 3208 Engines.
Illustration 1. Grind a chamfer of approximately 10° in the bottom of the cylinder bore.
Illustration 2. The 1P3565 Chamfering Tool.