The new Volvo Penta V8-380 sterndrive engine is intended to put big-block power in a small-block package. The 380-hp, 6.0-liter (364 cid) V8 engine replaces an 8.1-liter engine at this horsepower rating in the Volvo line, and made its public debut on Oct. 25 at the Ft. Lauderdale International Boat Show. The 8.1-liter engine was actually discontinued by General Motors in late 2009. Volvo stocked up on those engines before production ended and had enough inventory to last through May, 2012. The new engine is also based on a marinized General Motors truck power plant, the Vortec 6.0L (L96) VVT.

The new Volvo Penta V8-380 sterndrive engine.

The Volvo V8-380 is the first gas sterndrive or inboard engine to feature variable valve timing (VVT). A common feature on current auto engines, and also on Honda and Suzuki outboard motors, VVT broadens the powerband of the engine by changing the position of the camshaft relative to the crankshaft through a range of 26 degrees. This is a pushrod engine, so it has a single cam in the block, which is driven by the crankshaft through a timing chain. A hydraulic phaser using engine oil and managed by a solenoid turns the camshaft relative to its drive sprocket, thus adjusting the timing. The engine control module directs the phaser to advance or retard timing based on power demand. The exhaust and intake valves are adjusted at the same rate. The result is a broader over-all torque band – 90% of max torque is available from 2000 to 5500 rpm – with good bottom-end grunt and deep-breathing top-end power at its peak speed of 6000 rpm.

VVT and less displacement help the V8-380 achieve 12 percent better fuel economy than the engine it replaces, according to Volvo. In a combined engine and outdrive package, it weighs 270 pounds less than a 380-hp MerCruiser 8.2-liter  package, according to Volvo. Less weight is always a good thing in my book, but its impact on performance will be most significant in smaller boats. This is the first Volvo marine engine with aluminum cylinder heads and a cast iron block, and that’s one reason closed cooling is a standard feature on the V8-380, and includes circuits through aluminum exhaust manifolds and the oil cooler. Closed cooling also helps maintain a more constant oil and engine temperature, which aides efficiency. This engine is available with EVC electronic controls.

When the GM 8.1-liter engine went out of production, Mercury Marine made the decision to produce its own MerCruiser 8.2L engines, which use a GM block and components either designed by Mercury or source from suppliers. Mercury says it “places value on proven, tested, simple, reliable, and low RPM engines,” according to a spokesperson. “The benefits of the current strategy outweigh the potential benefits of increasing high-tech automotive technologies which do not translate fully to marine applications.” In other words, Mercury has chosen displacements and simplicity over light weight and technology.

Volvo has been shipping the V8-380 to boat builders since mid-summer, but I have not had a chance to sample the new engines. A source at one boat company tells me, however, that in his experience the V8-380 “exhibits a level of smoothness and precision that goes hand in hand with the latest engine designs.”

Boat builders set the retail price of engine options, and after checking with several it appears the Volvo Penta V8-380 will cost $2,100 to $2,500 less than an equivalent MerCruiser 8.2L Mag, at least for the coming season. That may be a price break to help get the engine into the market.

For more information visit Volvo Penta.

- Charles Plueddeman