PISTON 3843962 - Caterpillar

Illustration 1 g00295326
Double valve springs (1) Outer spring Length under test force ... 35.8 mm (1.41 inch) Test force ... 176 to 195 N (39.5 to 43.7 lb) (2) Inner spring Length under test force ... 34.0 mm (1.34 inch) Test force ... 89 to 104 N (20 to 23 lb)Single valve springs (if equipped) Length under test force ... 40.0 mm (1.57 inch) Test force ... 312 to 344 N (70.1 to 77.3 lb) (3) Valve spring recess for the valve spring (4) Valve guides for the inlet and exhaust valves Inside diameter ... 9.51 to 9.56 mm (0.3744 to 0.3764 inch) Outside diameter ... 15.90 to 15.91 mm (0.6260 to 0.6265 inch) Bore diameter in cylinder head for valve guide ... 15.87 to 15.89 mm (0.6247 to 0.6257 inch) Interference fit of valve guide in cylinder head ... 0.03 to 0.07 mm (0.0012 to 0.0027 inch)Overall length of valve guide Inlet ... 57.94 mm (2.281 inch) Exhaust ... 61.10 mm (2.406 inch) Projection of valve guide above valve spring recess (3) ... 15.10 mm (0.594 inch)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. (5) Diameter of the exhaust valve stem ... 9.43 to 9.46 mm (0.371 to 0.372 inch)Clearance of valve in valve guide ... 0.05 to 0.13 mm (0.002 to 0.005 inch)Maximum permissible clearance of valve in valve guide ... 0.15 mm (0.006 inch)Overall length of the exhaust valve ... 123.07 to 123.57 mm (4.845 to 4.865 inch) (6) Diameter of the inlet valve stem ... 9.46 to 9.49 mm (0.3725 to 0.3735 inch)Clearance of valve in valve guide ... 0.02 to 0.10 mm (0.0008 to 0.0039 inch)Maximum permissible clearance of valve in valve guide ... 0.13 mm (0.005 inch)Overall length of the inlet valve ... 122.66 to 123.07 mm (4.829 to 4.845 inch) (7) Angle of exhaust valve face ... 45 degrees (8) Diameter of the exhaust valve head ... 37.26 to 37.52 mm (1.467 to 1.477 inch)Valve depth below the cylinder head face Minimum ... 1.28 mm (0.050 inch) Maximum ... 1.60 mm (0.063 inch) Service wear limit ... 1.85 mm (0.073 inch) (9) Diameter of the inlet valve head ... 44.86 to 45.11 mm (1.766 to 1.776 inch)Valve depth below the cylinder head face Minimum ... 1.27 mm (0.050 inch) Maximum ... 1.60 mm (0.063 inch) Service wear limit ... 1.85 mm (0.073 inch) (10) Angle of inlet valve face ... 45 degreesNote: Some engines may have valve face angles of 30 degrees.The valve lash is