C3.3 Industrial Engine Caterpillar

Illustration 1	g00294082
Cross section of cylinder head

(1) Valve spring

Naturally aspirated engines

The installed length of the valve springs ... 33.5 mm (1.318 inch)

The load for the installed valve springs ... 254 N (57.1 lb)

Turbocharged engines

The installed length of the valve springs ... 34.5 mm (1.358 inch)

The load for the installed valve spring ... 229 N (51.4 lb)

(2) Valve spring recess

(3) The finished valve guides

Inside diameter of valve guide ... 9.000 to 9.022 mm (0.3543 to 0.3552 inch)

Outside diameter of the exhaust valve guide ... 13.034 to 13.047 mm (0.5131 to 0.5137 inch)

Outside diameter of the inlet valve guide ... 13.034 to 13.047 mm (0.5131 to 0.5137 inch)

Interference fit of valve guide in cylinder head ... 0.007 to 0.047 mm (0.0003 to 0.0019 inch)

Length of Valve guide ... 51.00 to 51.50 mm (2.018 to 2.027 inch)

Projection of the valve guide above the valve spring recess (2) ... 12.35 to 12.65 mm (0.486 to 0.498 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. The guides and inserts are then 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.

(4) Exhaust valve

Diameter of the exhaust valve stem ... 8.938 to 8.960 mm (0.3519 to 0.3528 inch)

Clearance of valve in valve guide ... 0.040 to 0.840 mm (0.0016 to 0.033 inch)

Overall length of the exhaust valve ... 128.92 to 129.37 mm (5.075 to 5.093 inch)

The face of the exhaust valve is recessed below the cylinder head by the following amount.

Naturally aspirated engines ... 0.53 to 0.81 mm (0.021 to 0.032 inch)

Service limit ... 1.06 mm (0.042 inch)

Turbocharged engines ... 1.53 to 1.81 mm (0.060 to 0.071 inch)

Service limit ... 2.06 mm (0.0811 inch)

(5) Inlet valve

Diameter of the inlet valve stem ... 8.953 to 8.975 mm (0.3525 to 0.3533 inch)

Clearance of valve in valve guide ... 0.025 to 0.069 mm (0.001 to 0.0027 inch)

Overall length of the inlet valve ... 128.92 to 129.37 mm (5.075 to 5.093 inch)

The face of the inlet valve is recessed below the cylinder head by the following amount.

Naturally aspirated engines ... 0.58 to 0.84 mm (0.023 to 0.033 inch)

Service limit ... 1.09 mm (0.043 inch)

Turbocharged engines ... 1.58 to 1.84 mm (0.062 to 0.072 inch)

Service limit ... 2.09 mm (0.0823 inch)

(6) Exhaust valve face angle from the vertical axis

Valve face angle ... 30 degrees

Valve seat angle ... 30 degrees

(7) Diameter of the exhaust valve head ... 41.51 to 41.75 mm (1.634 to 1.643 inch)

(8) Diameter of the head of the inlet valve ... 46.20 to 46.45 mm (1.818 to 1.828 inch)

(9) Angle of the inlet valve face from the vertical axis

Valve face angle ... 30 degrees

Valve seat angle ... 30 degrees

The valve lash is the following value when the engine is cold:

Inlet valves ... 0.20 mm (0.008 inch)

Exhaust valves ... 0.45 mm (0.018 inch)

Illustration 2	g00809016
Recess for the valve seat insert

(10) Machine the recess in the head for valve seat inserts to the following dimensions.

Recess for Inlet Valve Seat for Naturally Aspirated Engines

(A) ... 9.910 to 10.040 mm (0.3901 to 0.3952 inch)

(B) ... 47.820 to 47.845 mm (1.8826 to 1.8836 inch)

(C) Maximum radius ... 0.38 mm (0.015 inch)

Recess for Exhaust Valve Seat for Naturally Aspirated Engines

(A) ... 9.910 to 10.040 mm (0.3901 to 0.3952 inch)

(B) ... 42.420 to 42.445 mm (1.6701 to 1.6711 inch)

(C) Maximum radius ... 0.38 mm (0.015 inch)

Recess for Inlet Valve Seat for Turbocharged Engines

(A) ... 10.910 to 11.040 mm (0.4295 to 0.4346 inch)

(B) ... 47.820 to 47.845 mm (1.8826 to 1.8836 inch)

(C) Maximum radius ... 0.38 mm (0.015 inch)

Recess for Exhaust Valve Seat for Turbocharged Engines

(A) ... 10.910 to 11.040 mm (0.4295 to 0.4346 inch)

(B) ... 42.420 to 42.445 mm (1.6700 to 1.6710 inch)

(C) Maximum radius ... 0.38 mm (0.015 inch)