The Caterpillar 3126 was a 7.2 litre diesel engine offered in light to medium-duty buses and school buses.
The 3126 featured electronic controls with CAT's hydraulic electronically controlled unit injection fuel system (HEUI). The HEUI controls fuel injection to better meet emissions while maintaining attractive economy and performance.
Begining January 1998, a new version of the engine known as the 3126B was launched meeting the 1998 EPA, CARB, and Canadian emissions. The 3126B used an improved HEUI system with the HI150 injector for the 175 and 190 hp ratings and the HI300 injector on the higher output engines. The injectors use CAT's PRIME system (PReInjection-MEtering). A spill port located in the injector's plunger cavity allowed for a very short injection of fuel during the ignition delay period and before main injection. This helped reduce nitrogen oxide (NOx) and noise emissions. The engine boasted meeting the 1998 emissions without a catalytic converter.
The 3126E was made available beginning October 2002 as part of the "pull-ahead" to EPA 2004 emissions. This engine comes close to the emissions standard using some aspects of CAT's Advanced Combustion Emission Reduction Technology (ACERT). It was replaced by the Caterpillar C7 in 2004 which used all aspects of ACERT.
- Length: 42.8 in (1086mm)
- Width: 26.5 in (674mm)
- Height: 36.5 in (927mm)
- 439 cu in (7.2L)
Bore and stroke
- 4.33 x 5.0 in (110 x 127mm)
- Air To Air AfterCooled (ATAAC)
Weight (approx, dry)
- 1250 lbs (568 kg)
Below are engines commonly found in buses.
|Model||Max. Power||Max. revs||Max. Torque||Emmissions Certifications|
|3126||175 hp||2400 rpm||420 lb-ft @ 1440 rpm|
|3126||190 hp||2200 rpm||520 lb-ft @ 1440 rpm|
|3126||210 hp||2400 rpm||520 lb-ft @ 1440 rpm|
|3126||210 hp||2200 rpm||605 lb-ft @ 1440 rpm|
|3126||230||2200 rpm||660 lb-ft @ 1440 rpm|
|3126||250 hp||2200 rpm||660 lb-ft @ 1440 rpm|
|3126||250 hp||2200 rpm||800 lb-ft @ 1440 rpm|
|3126||275 hp||2200 rpm||800 lb-ft @ 1440 rpm|
|3126||275 hp||2200 rpm||860 lb-ft @ 1440 rpm|
|3126||300 hp||2200 rpm||800 lb-ft @ 1440 rpm|
|3126||300 hp||2200 rpm||860 lb-ft @ 1440 rpm|
- Cat's new 3126B midrange truck diesel - Caterpillar Inc. Engines Div, findarticles.com, retrieved on 2009-07-29
- CAT 3126, archive.org, retrieved on 2009-07-29