1991 Volvo Penta AQ231 5.0 L 305 V8 230 HP

FOR SALE 1991 Volvo Penta Aq231 5.0 L 305 V8 230 HP Boat Engine. FRESH WATER low HOURS 220 only. Very excellent condition and clean, great runs.

The 1991 Volvo Penta AQ231 is a highly reliable, General Motors (GM) sourced 5.0L (305 cubic inches) V8 engine. It is a carbureted marine engine that generates 230 horsepower. Known for its raw low-end torque, it was typically paired with Volvo Penta’s Aquamatic sterndrives (like the 290 or early Duoprop)

General Specifications

• Engine Type : 4-stroke V8 (GM Small-Block)
• Displacement : 5.0 L / 305 CID
• Horsepower : 230 HP
• Maximum RPM Range : 4,200 – 4,600 RPM
• Cylinder Bore : 3.736 in (94.9 mm)
• Stroke : 3.48 in (88.4 mm)
• Compression Ratio : 9.3:1

Fuel & Ignition Systems

• Fuel Type : Gasoline (minimum 87 AKI / 91 RON recommended)
• Fuel Delivery : Normally equipped with a marine-grade 4-barrel carburetor
• Ignition Timing : Typically set to 8° to 10° BTDC at idle (varies per specific model designation)
• Idle RPM : 600 – 700 RPM in gear

Fluid Capacities & Types

• Engine Oil Capacity : ~5.4 to 5.5 Liters (approx. 5.8 Quarts) with filter change
• Oil Weight : SAE 20W-50 or 25W-40 (high-quality marine 4-stroke oil)
• Coolant Capacity : ~14 to 15 Liters (depending on closed/raw water cooling configuration