FPT N67-550 Bobtail Inboard Marine Propulsion Engine

Description

Featuring a 550-horsepower continuous ceiling, the FPT N67-550 Marine Propulsion Engine bobtail configuration powers custom motor yachts, fast sport cruisers, and rapid response skiffs. Displacing 6.7 liters across six inline cylinders, this turbocharged four-stroke plant produces 550 brake horsepower at 3200 RPM. Second-generation common-rail injection feeds four valves per cylinder to produce blistering hole-shot acceleration without exhaust smoke.

Cast from high-density gray iron, this engine block features parent-bore cylinders and a forged alloy crankshaft balanced by seven main bearings. Marine cooling hardware includes a 70/30 cupronickel shell heat exchanger protected by replaceable sacrificial zinc anodes. Fuel lines hook to a #8 JIC flare inlet while raw sea water enters via a 2.0-inch hose barb. Bare bobtail weight measures 1,320 lbs, fitted inside an SAE #3 housing with a 16-quart oil pan.

Key Features of FPT N67-550

Express yacht builders buy FPT N67-550 inboard engine packages to give modern deep-V hulls high cruising speeds and quiet passenger comfort. The 6.7-liter inline-six platform produces massive boost to lift loaded hulls onto plane with ease without stern squat.

• High-pressure 1,800-bar common-rail injection meters fuel micro-charges to eliminate smoke during rapid hole-shot acceleration.
• Variable boost turbocharging refines N67-550 turbocharger efficiency across aggressive offshore cruising speeds.
• High-flow bronze raw water pump circulates 55 gallons per minute through the marine intercooler core.
• Viscous crankshaft vibration damper preserves marine transmission clutches during rapid forward and reverse shifting maneuvers.
• Top-mounted spin-on lube filters permit clean filter swaps without dropping oil down clean bilge gelcoat.
• Water-jacketed cast iron exhaust manifold keeps engine hold ambient temperatures low during warm summer runs.
• CAN-bus digital engine gateway outputs fuel burn rate and coolant temperatures straight to helm navigation displays.

Torque Dynamics Marine Thermal Thresholds

Producing 1,180 lb-ft torque at 2,000 RPM, this high-output diesel accelerates express cruisers onto plane in seconds. Operating coolant temperatures stay regulated between 165°F and 185°F under continuous cruising throttle. Common-rail fuel injection at 1,800 bar ensures uniform cylinder combustion, avoiding local thermal stress on valves and piston crowns. Sea water heat rejection totals 14,800 BTU per minute at full rating. Cruising fuel consumption records at 0.365 lb per horsepower-hour, providing balanced sprint capability and extended range between fuel bunkering stops.

Engine Stringer Exhaust Installation Clearance

Naval architects must preserve a 2.5-inch vertical drop below the oil pan base to clear engine stringer beds. The raw water discharge elbow connects to a 4.5-inch wet exhaust line in compliance with ABYC P-1 safety specifications. Resilient elastomer mounts isolate vibration while holding shaft coupling alignment to the marine gearbox.

Shift Routine Scheduled Maintenance Protocol

Electronic helm levers provide smooth governor response when maneuvering around mooring buoys and shallow harbor slips in gusty winds. This high-output sport marine diesel is not engineered for non-stop continuous commercial barge towing, abrasive river mud dredging, or dry exhaust piping runs lacking cooling sea water injection.

• Inspect raw sea water pump impellers and clear debris from intake strainers each shift.
• Drain primary fuel water separator bowls and test crankcase lube oil levels every 50 hours.
• Replace secondary spin-on fuel filters and inspect heat exchanger sacrificial zinc anodes every 250 hours.

Recreational Warranty Factory Crate Manifest

FPT covers this high-output propulsion engine with a 2-Year or 1,000-Hour recreational marine limited warranty. The wooden export crate contains the base core bobtail engine, four resilient vibration mounts, a digital instrument harness, an oil drain hose, and an official factory technical service manual.