Volvo Penta 8.1OSi-C: High-Performance Inboard Marine Propulsion The Volvo Penta 8.1OSi-C is a robust gasoline-powered inboard marine engine engineered for reliable propulsion in demanding boating applications. Produced from 2005 to 2006, this flagship 8.1-liter V8 inline engine delivers 375 horsepower (276 kW) at the crankshaft, making it the largest gasoline unit in Volvo Penta’s lineup and a proven choice for vessels requiring substantial thrust without compromising efficiency. Key technical specifications underscore its engineering excellence: an 8-cylinder inline configuration ensures balanced operation and minimal vibration, while direct injection (“Si-C”) technology injects fuel precisely into the combustion chamber for optimized combustion. Powered by gasoline and equipped with electronic fuel injection (EFI), it features advanced engine management systems with built-in diagnostics for proactive maintenance. The inboard design, constructed from corrosion-resistant aluminum alloys, integrates a heavy-duty cooling system to withstand thermal stresses, with no specified displacement details beyond its 8.1 L capacity, though it excels in marine-grade durability against saltwater exposure and fouling. Marine-specific benefits shine in its low-maintenance architecture, where efficient lubrication and cooling reduce wear in harsh environments, extending service intervals and enhancing operational reliability. Performance characteristics include a superior power-to-weight ratio for agile handling, reduced fuel consumption via direct injection—critical for extended voyages—and exceptionally low noise and vibration levels, promoting passenger comfort on the water. Ideal for medium- to large-scale applications, the 8.1OSi-C thrives in commercial fishing trawlers, leisure yachts, and offshore patrol boats, where its versatile inboard setup supports direct-drive or inboard-leg configurations. This engine embodies Volvo Penta’s commitment to dependable, high-impact marine propulsion, offering cost-effective performance for pre-2009 vessel builds seeking robust power without modern emissions complexities. (248 words)