|Number of Cylinders||6 Cylinders|
|Weight (lbs/kg)||899.00 lbs / 407.78 kg|
|Full Throttle RPM||5800|
|Engine Control System||Electronic|
Unlike the competition, Volvo Penta chose to continue their relationship with major engine supplier GM for its series of V6 sterndrive power platforms. The GM power utilizes an aluminum block and heads, variable valve timing (VVT) and direct-injection. Although the engine’s lightweight construction provides consumers with a better power to weight ratio, it is the VVT and in-cylinder fuel injection that delivers performance that boaters have never seen from such a compact design before.The new cylinder head features cathedral-shaped valves, direct, in-cylinder fuel injection and Iridium-tipped spark plugs.
New GM 4.3 L Block Design
There are some important changes in this engine’s design that make it a huge improvement over the older version for marine applications. Some of the details for these improvements are—
• By moving the fuel-injection point close to where it ignites, combustion efficiency is greatly improved – that means fuel burn is more complete, emissions are reduced, engine operating temperature is lowered, and the fuel mixture can be leaner, requiring less fuel to produce an equivalent horsepower.
• The variable valve timing system adjusts camshaft timing at the same rate for both intake and exhaust valves. This allows a linear delivery of torque, and near-peak levels across a wide rpm range.
• Variable-Displacement Oil Pump. Dual pressure controls allow the pump to operate at a different psi for different rpm settings, providing more of a robust lube system at high rpms where marine engines generally run.
• Oil Spray Piston Cooling. Six oil-spraying jets in the block under each piston drench the bottom of the piston and the cylinder walls with an added layer of cooling, friction reducing oil. This reduces engine temperatures and promotes longer engine life.
• High-Pressure Fuel Pump. The direct fuel-injection system is driven by a camshaft, powered by the engine under very high pressure to optimize fuel consumption.
• New Piston Alloys and Push Rods. New aluminum alloy pistons and strong push rods increase engine durability.
• New Spark Plugs. The spark plugs are Iridium tipped for better spark and longer life.
• New Intake Manifold. A high-flow intake manifold and electronic throttle make combustion and overall operation more efficient.
For testing, the engine was installed in a Cobalt 232 WSS and connected to a Volvo Penta DP sterndrive. The twin-wheeled lower unit ran FH5 props front and rear and had a final drive reduction ratio of 2.32:1.
On the water, our test rig weighed nearly 4,600 lbs. (2,086 kg) with test gear, a three-quarter tank of fuel and two people on board.Performance curve generated from the Volvo Penta V6 fitted in a Cobalt 232 WSS.
Hole Shot, Hot Shot
Most engine producers boast about low-end torque, it is part of the boating mantra. From our perspective, the 4.3 is going to set a new standard for seat-of-the-pants acceleration as the throttle response is quick and snappy from idle speed all the way up to about 4000 rpm when the torque curve starts to flatten out. This behavior will surprise skiers and boarders alike, as they will pop-up effortlessly.This chart shows our calculated test numbers from the 280-hp V6.
To quantify what we mean by this, our test boat got on plane in an average of 3.84 seconds and 20 mph was reached in an average of 5.37 seconds. This is exhilarating performance. Our test crew felt that some of the performance mannerisms are due to the modified fly-by-wire throttle controls. Our test vessel was not equipped with EVC, which provides true digital throttle control from the helm; instead our rigging used a cable-actuated binnacle throttle attached to a digital actuator at the engine’s throttle body.
All of Volvo Penta’s Gen V engines have electronic throttle control regardless of rigging. Block and Heads
The 280 horsepower is obtained from 262 cu. in. of displacement and is rated to spin up to 5800 rpm. The cylinder bores are 3.92” and their stroke is 3.62” long. The combustion chambers see a whopping 11.0:1 compression. The crankshaft is secured to the block with six bolt main caps for durabilityThe bottom end is capped-off using a structural aluminum oil pan that also helps reduce noise and vibration.After combustion, the exhaust exits through a water-jacketed aluminum manifold, and through a honeycomb style catalytic converter housed within.
Intake and Exhaust
The 4.3L takes advantage of a composite intake manifold in order to keep with the weight savings concept, and it also helps with keeping the intake air cooler. Once in the combustion chamber, the air is bathed in atomized fuel delivered at 2250 psi from the high pressure, in-cylinder mounted injectors.
There is one wide band sensor per manifold. These two sensors compare their readings within mili-seconds to control the air-fuel mixture, making the engine one of the cleanest on the planet. The engine complies with EPA and CARB emission regulations, as well as European Union’s Recreational Craft Directive (RCD).The ECU is mounted under the shroud and digitally communicates with the shift actuator shown here.
The engine’s Electronic Control Module (ECM) uses a closed loop emissions set-up for the pre- and post-catalyst oxygen sensors, and provides full diagnostics support as well as engine protection protocols should a failure occur. The ignition system uses a conventional ignition coil design; firing long-life Iridium tipped spark plugs, which helps to reduce maintenance costs and frequency.
We Recommend EVC Control
Those customers choosing the ‘E’ equipped engines will enjoy the benefits of Volvo Penta’s Electronic Vessel Control. The system provides true electronic throttle and shift control in addition to digital instrumentation. This system allows precise throttle adjustments at all rpm settings. We would have welcomed this option on the test boat.Shown in red, the engine uses a canister style oil-filter that uses a low-waste paper element.
Volvo Penta engineers came up with a novel approach to engine maintenance for the new family of sterndrives. It begins with the front of the engine where all the accessory systems are located. Typically, various brackets fasten the alternator, water pump and steering pump to the front of the block, while numerous hoses are intertwined to connect the sub systems to the engine. This design leads to numerous failure points and reliability issues.
So Volvo Penta developed FEAD (Front Engine Accessory Drive), this specially designed housing bolts to the front of the engine and supplies all the plumbing and mounting locations for the engine’s accessories.
This new design greatly reduces the number of hoses and connections points thereby increasing reliability. The FEAD also is standardized across the engine platforms, so the associated parts are all interchangeable with different size engines, reducing part inventory and easing service.
The V6 can be used with Volvo Penta’s SX drive in a hand full of final drive ratios 1.79:1, 1.89:1, and 1.97:1, and 2.18. Or for optimal performance, the twin-counter rotating wheels of the Duoprop drive in DPS, DPS OX formats with a ratio of 2.32:1.
Forward Drive. The latest invention for board sport applications is the Forward Drive (FWD) propulsion system that can be had in 1.95:1, 2.14:1, 2.32:1 ratios. All of the drives use pattern-matched spiral bevel gears and a cone clutch. They also incorporate a kick-up function should an object be struck while underway.