Cat's C9 ACERT Engine Tests Well
Caterpillar’s new C9 engine, employing the company’s ACERT emissions-reduction technology, gave a strong performance during recent on-road and off-road tests by Truckers News in Sterling medium-duty dumps at Caterpillar’s Peoria, Ill., facility.
The C9 showed excellent startability and the power to pull 6-percent grades in soft dirt. First gear was sufficient to overcome inertia for the Sterling LT9500, equipped with an Eaton Fuller 11908LL transmission, loaded to 58,000 pounds gross. The engine responded well to the load, making it unnecessary to use deep reduction (the bottom) gears and pulled through third gear before the top, a few hundred yards away. Torque peaks at 1,050 pounds-feet at 1,450 rpms.
The 335-horsepower C9 gave ample acceleration on the highway. One and two percent grades meant dropping one gear at highway speed.
While other engine manufacturers chose exhaust gas recirculation technology to meet tighter emissions requirements by Oct. 1, 2002, Caterpillar is meeting new standards with a combination of air and fuel management systems, electronics and diesel oxidation catalysts. Caterpillar officials also say the technology will enable the company to easily upgrade for meeting the 2007 emissions standards. The strategy has allowed Caterpillar to maintain high horsepower ratings and strong torque throughout the product line.
All ACERT products are in-line six-cylinder engines. However, the C7 and C9 do not use the twin turbo with an intercooler, which is used in engines rated C11 and higher. All engines use variable valve actuation to control air volume at various engine loads and speeds. Electronically controlled split injection allows more complete fuel burn at lower peak cylinder temperatures.
Caterpillar introduced its ACERT engines when it released the C9 in January. The C7 was released in June. Cat used its existing 3126E as the basis for the C7 and changed engine designations to match higher displacement. Thus the C8 becomes the C9, displacing 8.8 liters with horsepower ratings between 275 and 400. Comparable ratings above C9 have increased by one liter.
The 550-hp C15 will be the top horsepower-rated engine to be released this year. Caterpillar spokesperson Chuck Timmes said. Cat plans to top its line with the C16 early next year. Cat is taking orders on the C15. The C11 and 13 have not been certified as yet but plans are to release the 13 in October and the 11 in December after they are certified.