FNM 42HPEP-350 Sterndrive Adapter Marine Diesel Engine

Description

Bolt the FNM 42HPEP-350 Sterndrive Adapter Marine Diesel Engine into high-speed hulls to produce 350 BHP at 3,800 RPM. This 4-Stroke Inline-6 4.2L block pushes fast patrol interceptors through rough waters. The aggressive turbo profile demands strict 2-micron fuel pre-filtration to protect the common rail injectors from micron-level fuel contamination during extended open-throttle sprints.

CMD casts the parent-bore cylinder block from high-tensile gray iron to resist cylinder bore ovality under load. A single-piece 24-Valve cast iron monobloc head houses a single overhead camshaft that actuates rigid valve stems. Electrical components feature a 12V negative ground system powered by a 12V 2.8 kW starter and 12V 120A marine alternator. The dry engine stance weighs 992 lbs inside a compact envelope spanning 45.3in length, 28.3in width, and 30.9in height with a 2.77 gal oil sump.

Key Features of FNM 42HPEP-350

Commercial vessel operators buy FNM 42HPEP-350 sterndrive adapter engines to replace tired big-block gas units in offshore patrol craft. This package matches high-torque diesel efficiency with commercial sterndrive propulsion systems.

• Variable geometry turbocharger supplies immediate boost air across mid-range cruising speeds to cut smoke.
• Raw water intercooler lowers intake temperatures to protect piston crowns during maximum continuous load cycles.
• Tubular heat exchanger routes closed-circuit coolant to eliminate raw saltwater contact inside internal engine jackets.
• Electronic common rail direct injection atomizes fuel across multiple injection events per combustion stroke.
• Universal sterndrive adapter plate matches Mercruiser Bravo and Konrad transom assemblies without custom machining.
• SOHC 24-Valve valve train maintains precise valve timing across the entire 3,800 RPM operating band.
• Integrated engine oil cooler stabilizes lube viscosity during sustained full-throttle high-speed pursuit operations.

Dynamic Bench Load Tolerances

Dynamometer load cells record 250 BHP continuous output at 3,200 RPM and 350 BHP maximum rating at 3,800 RPM. Peak shaft torque reaches 531 ft-lbs at 2,400 RPM while manifold boost pressure climbs to 2.1 bar. Heat exchanger circuits stabilize jacket coolant at 185°F under full thermal saturation. Main crankshaft journals hold 0.0005in TIR runout tolerances across all seven main bearings. Normal lube oil pressure maintains 58 PSI at rated speed, while the oil pan supports static vessel installation angles up to 20°.

Field Usability Maintenance Protocol

Electronic helm throttle levers require zero mechanical cable drag, while emergency backup manual linkages demand 6 lbs push effort. Do not install this high-strung 3,800 RPM propulsion package in commercial workboat diesel engine repower hulls that push heavy displacement barges at slow hull speeds.

• Drain and replace 2.77 gal of crankcase lube oil every 250 operating hours.
• Spin off primary 2-micron fuel filters and drain water separator bowls every 200 service hours.
• Inspect zinc sacrificial anodes on the raw water heat exchanger housing every 100 run hours.

Verified Warranty Crate Manifest

FNM CMD backs this assembly with an official 2-Year limited marine warranty. Each export shipping crate contains the complete 42HPEP-350 bobtail core, sterndrive adapter plate, 12V electric starter, 120A alternator, flexible isolation mounts, marine wiring harness, digital instrument display interface, and factory service manuals to direct yard technicians.