1986/10/01 Caterpillar

D333C And 3306 Engines

Caterpillar frequently conducts tests of competitive parts to evaluate their quality and performance capabilities. A comparison of CGR-Ghinassi cylinder heads to Caterpillar D333C and 3306 Cylinder Heads (Metallurgical and dimensional evaluations) was recently completed. The following is a summary of what our tests revealed.

Summary

If these Ghinassi cylinder heads are representative of their overall production and we make no representation that they are, then Ghinassi cylinder heads cannot be recommended for use on Caterpillar engines.

Because of the test, we feel these cylinder heads could cause severe engine damage since they do not meet Caterpillar high quality and performance standards.

Key Critical Points

Cleanliness:

... Metal chips and drillings were found throughout internal passages. These chips and debris, if not cleaned out before installation, could cause extensive engine damage.

Casting Defects:

... Coolant passages and intake and exhaust ports were partially blocked by burned-in core sand and metal fins. Resulting inadequate circulation could cause overheating and cracks.

... Wall thickness was inadequate in critical high temperature areas. The resulting stress could lead to head cracking.

Incorrect Machining:

... The precombustion chamber seats had chatter marks. Chatter marks could cause coolant and combustion leaks.

... Several cup plug openings were found to be oversized once the freeze plugs were removed. Initial sealing would be adequate, but there is potential for leaks in the future.

... The depth of the valve spring seats were undersize from the minimum allowable Caterpillar specification. This undersize depth would cause increased valve train wear and lead to failure.

... Two water outlet holes (used for hookup of temperature gauge sending units or heater hoses) were incorrectly machined. Both situations would cause additional downtime and increase installation costs.

... The prechamber holes in the bottom deck were not counterbored, leaving partial threads at their intersection. These holes, without counterbores, act as a stress raiser which could lead to bottom deck cracking.

... A dowel hole on the cylinder head combustion face was oversize. This could cause head location problems.

Illustration 1. Chatter marks were found in the precombustion chamber seats and valve guide openings. This is a potential source for gas leaks into the coolant or coolant into the cylinder.

Noncurrent Design:

... The cylinder head (Ghinassi 8N1187) in Illustrations 1 and 2 is copied from an earlier Cat design. The current Cat design improves venting of the cooling system. Outdated head design can create improper cooling system performance and higher customer operating costs.

Illustration 2. Both of these situations would create installation problems for the mechanic.

Conclusion

The substantial number of nonconformances identified during the testing process provides proof that Caterpillar cylinder heads and the Ghinassi cylinder heads tested are definitely not of the same quality. Use of Ghinassi cylinder heads on a Cat Engine could cause serious damage to the engine and unnecessary downtime and repair expenses for the customer. Genuine Caterpillar cylinder heads are designed to meet the high standards and long service life Caterpillar Engine customers have come to expect.

The information contained herein was developed by testing randomly sampled current Ghinassi cylinder heads and compared to Caterpillar print specifications. No implication is intended, and no inference should be drawn that these parts are representative of Ghinassi's overall production.

Reproduction of this article must include the above statement.