- Engines:
- 3606 (S/N: 8RB1-UP)
- 3608 (S/N: 6MC1-UP)
- 3612 (S/N: 9RC1-UP; 9FR1-UP; 2NZ1-UP)
- 3616 (S/N: 1PD1-UP; 1FN1-UP)
- 3618 (S/N: 2MW1-UP)
Description of Change: New basic cylinder head groups are used on these distillate fuel engines. The new cylinder heads include new premachined valve seat inserts and precision valve guides. The premachined inserts provide the following advantages:
- improved reliability
- simplified field service
Adaptable To: The new cylinder heads are effective with the engines that are listed in Table 1. The new cylinder heads are adaptable to all earlier 3600 Engines that are used in distillate fuel applications.
| Effectivity of the New Cylinder Heads | |
|---|---|
| Engine Model | Effective Serial Numbers |
| 3606 | S/N:8RB773-UP |
| 3608 | S/N:6MC616-UP |
| 3612 | S/N:9RC319-UP S/N:9FR21-UP S/N:2NZ176-UP |
| 3616 | S/N:1PD364-UP S/N:1FN150-UP |
| 3618 | S/N:2MW86-UP |
Note: The cylinder head groups are not available for parts service. The cylinder heads are serviced at the "basic cylinder head group" level.
| Cylinder Head Groups | |||
| Application | Cylinder Head Group Pt. No. (1) | New Basic Cylinder Head Group Pt. No. | Former Basic Cylinder Head Group Pt. No. |
| Standard (Constant Load) | 1W-0021 | 175-6340 | 7E-9012 |
| Standard (Cyclic Load) | 4P-2335 | 175-6341 | 4P-2334 |
| Injector Tip Cooling (2) | 107-0275 | 175-6336 | 107-0274 |
| 3618 | 138-7908 | 180-5344 (3) | 138-7907 (3) |
| Fast Ferry | 164-7886 | 176-3600 | 164-7885 |
| ( 1 ) | These part numbers are not serviced. The cylinder heads are serviced at the "basic cylinder head group" level. |
| ( 2 ) | These cylinder heads are used in light crude applications. |
| ( 3 ) | The new 180-5344 Basic Cylinder Head Group has 20 degree inlet valves. The former 138-7907 Basic Cylinder Head Group has 30 degree inlet valves. |
Note: The valve seat counterbores in the former cylinder heads were not machined to the same tolerance as the new cylinder heads. When the former cylinder heads are rebuilt, continue to use the former valve seat inserts.
| Major Components of the New Basic Cylinder Head Groups | ||||||
| Basic Cylinder Head Group | Inlet Valves | Exhaust Valves | Valve Guides | Cylinder Head Assembly (1) | Inlet Valve Seat Inserts (2) | Exhaust Valve Seat Inserts (2) |
| 175-6340 | 7C-2422 | 9Y-6232 | 175-6344 | 175-6339 | 160-5769 | 160-5770 |
| 175-6341 | 9Y-6232 | 9Y-6232 | 175-6344 | 175-6339 | 160-5769 | 160-5770 |
| 175-6336 | 9Y-6232 | 9Y-6232 | 175-6344 | 175-6334 | 160-5769 | 160-5770 |
| 180-5344 | 180-9044 | 4P-3079 | 175-6344 | 180-5345 | 171-3992 | 160-5771 |
| 176-3600 | 9Y-6232 | 4P-3079 | 175-6344 | 176-3599 (1) | 160-5770 | 160-5771 |
| ( 1 ) | The 176-3599 Cylinder Head Assembly is available for parts service. The remaining cylinder head assemblies in this column are not available for parts service. All cylinder heads are serviceable at the "Basic Cylinder Head Group" level. |
| ( 2 ) | The valve seat inserts are components of the cylinder head assemblies. The inserts are available individually for parts service. |
Note: Do not perform any machining or lapping on the valves or seat inserts after installation. Proper seating is established very early in the break-in period.
Note: It is VERY IMPORTANT to perform bridge adjustment and valve lash adjustment at the proper interval. The recommended interval for each specific application can be found in the Operation and Maintenance Manual for the engine.