Cummins QSB6.7 Heavy Displacement Trawler Marine Diesel Engine

Description

Strict EPA Tier 3 environmental mandates create propulsion hurdles for long-range trawler conversions. The Cummins QSB6.7 Heavy Displacement Trawler Engine solves these challenges by combining Bosch high-pressure common rail injection with 250 BHP continuous output from a 6-Cylinder 6.7L block. Keel-cooled grids protect internal water passages, though offshore skippers must verify fuel cleanliness through 2-micron primary filtration.

Metallurgists specify high-strength pearlitic gray iron for the parent-bore cylinder block to withstand thousands of continuous ocean hours. A single-piece 24-Valve cylinder head controls air distribution into all 6 combustion chambers. The 24V isolated ground electrical system includes a 4.5 kW starter motor and 70A alternator to protect steel trawler hulls. Dry mass weighs 1,450 lbs inside an installation envelope measuring 49.7in length, 35.4in width, and 33.7in height, with a 4.0 US gal sump.

Key Features of Cummins QSB6.7 Heavy Displacement

Expedition voyagers buy Cummins QSB6.7 Heavy Displacement Trawler engines to power transoceanic passages without mechanical intervention. This keel-cooled propulsion package eliminates raw water pumps and raw water strainer maintenance during offshore crossings.

• Continuous P1 commercial rating produces 250 BHP at 2,600 RPM for endless ocean passages.
• Keel-cooled closed grid architecture eliminates raw water impeller failures and heat exchanger fouling.
• Bosch high-pressure common rail injection atomizes fuel at 1,600 bar for smoke-free cruising.
• SAE 3 flywheel housing pairs with heavy Twin Disc MG-5065A and MG-5075A transmissions.
• EPA Marine Tier 3 compliance allows clean legal passage across all North American waters.
• Deep commercial oil pan carries 4.0 US gal for steady lubrication during 30° rolls.
• Dry exhaust configuration routes gases overhead to prevent hull side soot accumulation.

Ocean Trawler Dynamometer Performance Data

Dynamometer tests verify 250 BHP continuous output at 2,600 RPM and 658 ft-lbs peak shaft torque. Boost pressure stabilizes at 1.85 bar under continuous load while injection rail pressure maintains 1,600 bar. The closed keel cooler grid keeps engine coolant at 182°F during continuous high-load towing. Dry exhaust stack temperatures stabilize at 920°F at the turbo outlet. Oil gallery pressure measures 46 PSI at idle and reaches 66 PSI under cruise load with journal runout below 0.0005in TIR.

Trawler Machinery Space Service Criteria

Electronic throttle controls link to wheelhouse consoles while mechanical emergency levers move with 8 lbs of manual push-pull effort. Do not mount this keel-cooled trawler commercial workboat diesel engine repower package into high-speed planing sportfish hulls or shallow draft skiffs that lack space for external hull cooling tubes.

• Drain crankcase oil and replace spin-on lube filters every 250 operating hours.
• Replace primary and secondary fuel filter elements every 500 running hours.
• Inspect hull keel cooler tubes and external zinc anodes every 12 months.

Crate Hardware Factory Warranty Manifest

Cummins covers this heavy displacement engine with a 2-Year or 2,000-Hour factory commercial warranty. Each shipping crate contains the complete bobtail engine, 24V starter, 70A alternator, steel flexible mounting brackets, remote engine instrument harness, lube oil pressure sensors, and detailed factory shop service manuals.