Volvo Penta D2-50 Inboard Diesel HS25A Gearbox Package

Description

Lower offshore cruiser fuel consumption with Volvo Penta D2-50 HS25A Package systems, designed to power cruising sailboats, motor sailors, and small trawlers up to 42 feet. Displacing 2,170 cc across four cylinders, this naturally aspirated diesel generates 51 horsepower at 3,000 RPM. Mechanical unit injection meters fuel with precision, delivering smooth idle speeds, clean combustion, and low vibration during harbor maneuvering.

High-tensile gray cast iron forms the monolithic cylinder block, equipped with induction-hardened parent cylinder walls that resist scuffing. A fresh water cooling system integrates an aluminum heat exchanger housing with a cupronickel tube bundle and bronze sea water pump. Dry package weight with HS25A gearbox is 573 lbs, supported by a 5.8-quart stamped oil pan and 0.312-inch hose barb fuel fittings.

Key Features of Volvo Penta D2-50

Cruising sailors buy Volvo Penta D2-50 inboard engine packages to replace obsolete shaft drive installations inside compact sailboat engine compartments. The paired HS25A hydraulic transmission features an eight-degree down angle to simplify shaft alignment in steep keel configurations.

• 51 horsepower rating propels displacement sailing craft at hull speed in head seas.
• 115-amp 12-volt alternator with built-in charging sensor recharges house battery banks.
• HS25A hydraulic gearbox delivers smooth proportional shifting during docking maneuvers.
• Cupronickel tube heat exchanger protects cylinder jackets from salt scale accumulation.
• Electric glow plugs initiate rapid combustion down to freezing bilge temperatures.
• Volvo Penta D2-50 auxiliary efficiency lowers fuel burn on extended coastal passages.
• Flexible rubber engine mounts dampen four-cylinder reciprocating pulses to protect stringers.
• Front-mounted sea water pump allows quick neoprene impeller replacement through hatch doors.

Combustion Dynamics Thermal Capacities

Coolant thermostats regulate internal temperatures between 168°F and 182°F under continuous motoring operations. The four-cylinder block develops 98 lb-ft of torque at 2,000 RPM, giving displacement sailboats power to punch through tidal headlands and harbor chop. Rated for M4 pleasure craft service, thermal heat rejection transfers 35 kW into raw water cooling circuits. Specific fuel consumption averages 232 g/kWh, burning about 0.85 gallons per hour at standard yacht cruising speeds across open coastal waters.

Exhaust Integration Bay Clearances

A water-injected exhaust elbow attaches to 2.5-inch wet exhaust hose, meeting ABYC P-1 standards for auxiliary sailboats. Mounting brackets adjust across 18-inch to 20-inch stringer centers, preserving 2.25 inches of clearance below the oil pan. Flexible elastomer mounts absorb vibration from the hull.

Service Schedules Application Constraints

Direct mechanical Morse cables connect helm control levers straight to governor and gearbox selectors for immediate response. Operators inspect raw water strainers, check oil levels, and monitor belt tension before getting underway. This engine package is not engineered for offshore planing hulls, commercial trawlers, or raw water cooled bilges without fresh water heat exchangers.

• Inspect sea water intake strainer before each shift.
• Inspect and clean heat exchanger zincs every 150 hours.
• Change engine lube oil, gear oil, and filters every 200 hours.

Warranty Terms Package Manifest

Recreational buyers receive 2-Year limited warranty protection on base castings and mechanical components. The shipping crate contains the engine, HS25A gearbox, vibration isolators, digital instrument cluster, five-meter extension wiring harness, oil extraction pump, and a complete technical service manual.