G3500B Engines Caterpillar

Illustration 1	g01347856

(1) The valve guide bore does not require machining after installation.

(A) Bore of valve guide before installation ... 9.481 ± 0.008 mm (0.3733 ± 0.0003 inch)

(B) Dimension from top of cylinder head to top of valve guide ... 26.0 ± 1.0 mm (1.02 ± 0.04 inch)

(2) For installation, reduce the temperature of the oil sleeve to −60 °C (−76 °F).

Note: The valve seat insert does not require machining after installation.

(3) For installation, reduce the temperature of the valve seat insert to −60 °C (−76 °F). Press the insert into the cylinder head counterbore. Do not hammer the valve seat insert.

(C) Counterbore depth ... 16.00 ± 0.15 mm (0.630 ± 0.006 inch)

(D) Outer diameter of valve seat inserts

Inlet valve seat insert ... 60.640 ± 0.015 mm (2.3874 ± 0.0006 inch)

Exhaust valve seat insert ... 60.132 ± 0.015 mm (2.3674 ± 0.0006 inch)

(E) Counterbore diameter

Inlet valve seat insert ... 60.508 ± 0.025 mm (2.3822 ± 0.0010 inch)

Exhaust valve seat insert ... 60.000 ± 0.025 mm (2.3622 ± 0.0010 inch)

(F) Angle of insert seating surface for valve ... 20.25 ± 0.25 degrees

(G) Distance from bottom of oil sleeve to bottom of chamfer ... 16.5 ± 1.0 mm (0.65 ± 0.04 inch)

Illustration 2	g01348403

(4) 7N-1904 Spring

Length under test force ... 56.36 mm (2.219 inch)

Test force ... 245 ± 25 N (55 ± 5.6 lb)

Free length after test ... 62.5 mm (2.46 inch)

Outside diameter ... 43.92 mm (1.730 inch)

(5) 7N-1903 Spring

Length under test force ... 45.49 mm (1.791 inch)

Test force ... 125 ± 12 N (28 ± 2.7 lb)

Free length after test ... 51.54 mm (2.029 inch)

Outside diameter ... 29.24 mm (1.151 inch)

(6) Coat the valve stem with clean engine oil before assembly.

(H) Diameter of new valve stem in the area of the valve guide ... 9.441 ± 0.010 mm (0.3717 ± 0.0004 inch)

(J) Angle of valve seat ... 20.25 ± 0.25 degrees

(K) Diameter of valve head ... 56.00 ± 0.15 mm (2.205 ± 0.006 inch)

Illustration 3	g02149538
Typical example of the orientation of the inlet valve seats for a swirl combustion head

(L) Orientation of the inlet valve seats ... 45 ± 5 degrees