1988/04/01 Caterpillar

Caterpillar now offers Remanufactured Cylinder Head groups, to service 100% of 3406 Engines back to first production. Because of design changes since first production, cylinder heads for 3406 have several different service part numbers. This article summarizes the information for determining the correct cylinder head repair option for each type of 3406 Engine.

Remanufactured Cylinder Head Groups

... 0R0945 (original alloy or modified alloy casting) fits all 3406 Precombustion Chamber Engines.

... 0R0977¹ (compacted graphite or modified alloy casting) fits all 3406 Direct Injection Engines with 55 mm adapter bore, except Series B Engines.

... 0R1445¹ (original alloy casting) fits all 3406 Direct Injection Engines of 350 hp or less (including all vehicular applications) with 55 mm adapter bore, except Series B Engines.

... 0R1160 (modified alloy casting/40 mm adapter bore, includes double valve springs) fits all 3406B Truck Engines and requires the later style nozzle.

... 0R1161 (modified alloy casting/40 mm adapter bore) fits all 3406B Engines in applications other than trucks and requires the later style nozzle.

---

¹These cylinder heads can contain either six of the former adapter (1W7884, lots 12 and up) or the current style adapter. Adapters will not be mixed on a given head. The 1W7884 Adapter, lots 12 and up, is permissible for reuse and Caterpillar reuses those that meet specification. Each Remanufactured Head will have the necessary hardware for the adapters used in that head.

Important Points To Remember When Selling Remanufactured Cylinder Heads' Lower Price Offering (0R1445 Cylinder Head Group)

The 0R1445 Cylinder Head Group is a relatively new offering in the Remanufactured Program and fits 3406 DI Engines of 350 hp or less including all vehicular applications (not adaptable to 3406B Engines). It uses the original alloy iron casting which conforms 100% to engineering standards at lower horsepowers. This group is priced approximately $180 below the suggested consumer price for 0R0977 Head. Customers with lower horsepower engines can receive the same benefits as the higher priced 0R0977 Head and save $180. Unless there are plans to raise the horsepower of the engine above 350 hp, the lower priced 0R1445 Cylinder Head Group should be purchased.

Head Groups For Earlier 3406B Engines

3406B Engines in the following serial number ranges used a cylinder head with a 55 mm adapter:

3406B Truck: 7FB1-21131

Because the 40 mm design head is superior to the 55 mm design head, Caterpillar has elected to offer only the 40 mm design casting (modified alloy) for Remanufactured Head Groups for 3406B Engines. For engines in the above serial number ranges, this can mean additional costs for a Remanufactured Head Group.

1. If the nozzles are the former style, they will have to be replaced. The cost of six Remanufactured Nozzles (available in October 1986) is approximately $180. However, this expense should not be viewed as additional unneeded expense, because nozzles should be tested and replaced if necessary every 100,000 miles. Some nozzles will probably need replacing when the cylinder head is replaced.

2. If the original engine had a Jacobs Brake® installed, the exhaust bridges must be replaced at a cost of approximately $250. Contact a Jacobs dealer for instructions on replacing the original bridges.

While there is additional cost in upgrading to the improved head group, Caterpillar recommends the change because of the longer life characteristics of the improved head group. To avoid the additional costs of using the latest head, it is possible to convert a 0R0977 Head. The casting and valves in 0R0977 are adaptable to earlier 3406B Engines. By reusing the adapters, springs, valve rotators and valve spring washers from the core, you can build up a head group that allows reuse of the original fuel nozzles and Jacobs Brake bridges.

Caterpillar's Remanufactured Cylinder Head Program is intended to provide reliable value-priced repair options. Caterpillar believes it is providing the best value with the current head offering for 3406B Engines and encourages their use in repair situations.