2008/07/21 Caterpillar

Engine:

G3408 (S/N: 6NB1-UP; 6RJ1-UP; 8YR1-UP; BAZ1-UP)

G3412 (S/N: 7DB1-UP; 6ZM1-UP; 9RR1-UP)

G3412C (S/N: 8LW1-UP)

G3412 (S/N: R7A1-UP)

Generator Set:

G3412 (S/N: KAP1-UP)

Engine News SEBD9432, February 2007, "New Inlet Valve Guide Seal and New Cylinder Head Groups". Disregard this article. Refer to the article that follows.

Description of Change: A new piston ring set has been released in order to reduce oil consumption on engines that operate at low loads. The new piston rings will reduce the overall oil consumption. The top piston ring and the intermediate piston ring have been in production, but the top piston ring and the intermediate piston ring have not been used together. The oil ring is new and the new oil ring will limit the oil that is dispersed in the cylinder. Refer to Tables 2 and 3. The new average Brake Specific Oil Consumption (BSOC) should be 0.183 ± 0.061 g/Bkw-hr (0.0003 ± 0.0001 lb/Bhp-hr).

The inlet valve guide seal is designed to grip the top of the inlet valve guide. The inlet valve guide seal has a flange that sits on the top deck of the cylinder head and the valve spring sits on top of the flange. The inlet valve guide seal can only be installed if the inlet valve guide has been installed to a height (the cylinder head top deck) of 26 ± 0.8 mm (1.024 ± 0.032 inch). Some early cylinder heads had the valve guides (inlet and exhaust) installed to 32.3 ± 0.8 mm (1.272 ± 0.032 inch).

Adaptable To: The 214-6051 Valve Stem Seal replaces the 250-3044 Valve Stem Seal which is cancelled. The new seal is part of the new cylinder head groups that are listed in Table 1. The new cylinder head groups were manufactured after 20November 2006.

Table 1

New Part Number for Cylinder Head Group	Old Part Number for Cylinder Head Group	Remanufactured Part Number
300-5527	206-7745	10R-1134
300-5525	206-7748	10R-1137
311-7557	223-6523	10R-6279
311-7556	223-6524	10R-6280
300-5524	223-6521	N/A (1)

( 1 )

At this time, no cylinder heads have been produced.

The former piston and rod group is replaced by the new piston and rod group. Refer to Table 2.

Table 2

Former Piston and Rod Gp	New Piston and Rod Gp	Compression Ratio
160-7993	257-2692	11.4:1
160-7995	257-2693	8.5:1
160-7990	257-2694	9.5:1

Table 3

New Piston Ring Set
Part Number	Description
150-4789	Piston Ring (Top)
100-5080	Piston Ring (Intermediate)
250-0872	Piston Ring (Oil)

Illustration 1	g01185239
(1) Inlet valve guide seal

(A) Distance from the top of the cylinder head to the top of the valve guide ... 26 ± 0.80 mm (1.024 ± 0.032 inch)