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Verified Technologies for SmartWay and Clean Diesel

Caterpillar Technology—Marine Engine Emissions Upgrade Group Kit #6 (Tier 1 to Tier 2)

This retrofit technology is included on EPA's Verified Technologies List for Clean Diesel.

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Technology specifications

Engine Model/Application

Caterpillar 3508, 3512, and 3516 (large cam bore) diesel engines for non-road marine applications, model year 1994 – 2006; Tier 1 engine and rated at 1200, 1600, or 1800 rpm (varies by model)

Retrofit Fuel, Max Sulfur 15 parts per million (ppm)
Reduction in particulate matter (PM) 0.27g/kW-hr (Marine Diesel Engine Tier 2 Level) a
Reduction in nitrogen oxide (NOx) 7.8g/kW-hr (Marine Diesel Engine Tier 2 Level) a
Reduction in hydrocarbons (HC) 7.8g/kW-hr (Marine Diesel Engine Tier 2 Level) a
Reduction in carbon monoxide (CO) 5.0g/kW-hr (Marine Diesel Engine Tier 2 Level) a

a The Diesel Emissions Quantifier (DEQ) may be used to estimate reductions from Tier 0 (or unregulated) to Tier 2 levels.

Caterpillar has indicated there is an approximately 1 percent fuel economy penalty with the use of this technology.

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Criteria to achieve emission reductions

This technology is approved for Caterpillar 3500 Series Tier 1 marine variable speed propulsion engines with rated power greater than 600 horsepower originally manufactured between 1994 and 2006 model years and rated at 1200, 1600 or 1800 rpm. Please note that this verification is based on the ISO 8178 E3 general marine duty cycle only. The following criteria must be met in order for appropriately retrofitted engines to achieve the aforementioned emission reductions:

  1. The servicing dealer must follow specific installation instructions approved by Caterpillar and validate that the upgraded engine has the necessary components installed and has been tested to ensure the proper fuel delivery, power, torque and speed.  The dealer must submit a validation form to Caterpillar in order to receive a label for the upgraded engine. 
  2. The original Caterpillar 3500 Marine Engine must be a certified Tier 1 engine and the electronic control module (ECM) must be replaced or updated as part of the upgrade. The primary critical new components are turbocharger, fuel pump/governor, nozzles, cylinder packs, jacket water after-cooler, and other installation parts as necessary.
  3. The engine must be operated on ultra-low sulfur diesel fuel (ULSD) of 15 ppm or less.
  4. This verification is for engines used in vessels with variable speed propulsion systems and is not applicable for engines used in recreational or constant speed propulsion applications.

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Verification Letter from EPA

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