2001/11/12 Caterpillar

Engine:

3056 (S/N: 8XJ1-UP)

Specifications, SENR5024, "3056 Engine for Caterpillar Built Machines", "Cylinder Head Valves". The specifications on the valve seat inserts and valve guides are added to Specifications, SENR5024, "3056 Engine for Caterpillar Built Machines", "Cylinder Head Valves". Add the following information:

Note: When new valve guides are installed, new valves and new valve seat inserts must be installed. The valve guides and the valve seat inserts are supplied as partially finished parts. The unfinished valve guides and unfinished valve seat inserts are installed in the cylinder head. Then, the guides and inserts are cut and reamed in one operation with special tooling. This procedure ensures the concentricity of the valve seat to the valve guide in order to create a seal that is tight. Refer to the Disassembly and Assembly Manual for removal and installation procedures.

Note: When a new valve seat insert is installed, a new valve and valve guide must be installed. Refer to the Disassembly and Assembly Manual for removal and installation procedures.

Illustration 1	g00840530

(11) Valve seat insert

Naturally aspirated engine

(D) Included angle of the faces of the valve seat insert ... 118 degrees

(E) Horizontal dimension of the chamfer ... 0.38 mm (0.015 inch)

(F) Vertical dimension of the chamfer ... 0.38 mm (0.015 inch)

Turbocharged engine

(D) Included angle of the faces of the valve seat insert ... 88 degrees

(E) Horizontal dimension of the chamfer ... 0.38 mm (0.015 inch)

(F) Vertical dimension of the chamfer ... 0.38 mm (0.015 inch)