Volvo Penta D2-55 marine diesel

Other than Bukh

The naturally aspirated Volvo Penta D2-55 is one such marine diesel engine. The base Volvo Penta engine is made in Japan, then shipped to Sweden for marinisation. That’s no bad thing because during the transformation Volvo incorporates features that make it equally at home powering a displacement cruiser, monohull keel boat or, in twin installations, sail and power cats.

Volvo Penta D2-55 marine diesel

The Volvo Penta D2-55 diesel engine features a deep sump that allows a massive 35° of heel port or starboard without suffering oil starvation during extended motor sailing, and a whopping 115amp voltage-regulated alternator that still pumps out 35 amps idling at 850rpm. And unlike the competition, Volvo provides crankshaft and propshaft engine outputs for real-world comparisons of power, not just what the engine itself develops.

Having said that, there’s nothing fancy about this indirect injection engine. Just two valves per cylinder and heat-exchanger cooling but the exhaust manifold is freshwater-cooled instead of using raw (salt) water – this reduces potential corrosion in the manifold from condensation build up during periods of inactivity. Raw water is injected into the exhaust elbow; combined with the maximum exhaust gas temperature of 570 degrees, the water injection enables rubber exhaust hose to be used out to the transom.

The raw-water pump on the Volvo Penta D2-55 marine diesel engine is gear-driven while the freshwater pump and alternator are driven by a V-belt from the crankshaft. All are accessed from the forward end of the engine. There’s no shroud over the belt as the logical Swedes think only a moron would poke around near a rapidly moving belt, but a nice touch is the auxiliary engine stop button on the engine, so if an owner is working around the engine while it’s running, there’s the possibility of saving some fingers if they accidentally touch the belt. The 2.0kW starter motor is mounted well up the block, in line with the alternator, and glow plugs are provided for easier cold starting.

Engine maintenance

A spin-on canister oil filter makes changing oil in the large 10.6 litre sump easy. Volvo doesn’t specify its recommended oil viscosity in the tech specs but I’d suggest an SAE 10W30 oil for cooler climates and SAE 15W40 for tropical conditions. Change the oil and filter every 200 running hours or annually. Sump oil may be topped up using either top or side-mounted filler caps depending on installation.

The fuel sedimenter and filter for the conventional inline fuel injection pump are also mounted at the forward end. The whole mechanical system is easy to maintain and service.

Thankfully the tachometer supplied reads to 4000rpm, not 5000 as with some of the competition – I hate looking at an over-optimistic tacho! Included in the standard instrument panel are a digital hour meter and engine overheat and low oil-pressure alarms but I’d indulge in the optional panel that has fuel level, engine overheat and voltage output gauges too. The instrumentation can be interfaced through NMEA electronics to display this info on your chart plotter.

Transmission options

Volvo offers a range of transmission options; there are mechanical and hydraulic gearboxes, and a sail drive where the engine can be mounted ahead or aft of the leg. Unusually for an engine of this output, the gearboxes offer the choice of clockwise or counter-clockwise output rotation, so in twin shaft-drive installations the props can be handed to counter prop torque. For shaft-drive yacht installations I’d opt for the mechanical MS25A gearbox which has an eight-degree down angle at the output flange and can handle a freewheeling prop without suffering damage. Clockwise propshaft rotation ratios are 2.23:1 and 2.74:1, the latter a bit deep for yachts because of the much larger prop that can be swung.

The hydraulic HS25A ’box is better suited to cruisers and is available with clockwise output 2.29:1 and 2.71:1 ratios, the latter excellent for heavy displacement cruisers. In these types of hulls the propshaft angle is likely to be no more than eight degrees so the engine can be mounted parallel to the waterline, ensuring all the old oil can be extracted from the sump during changes.

Volvo realises that the sail drive will be used with lighter displacement hulls and it has a 2.19:1 ratio.

Having mechanical injection with fixed timing, the Volvo Penta D2-55 marine diesel should not be run continuously below 2000rpm or cylinder bore glazing may occur from fuel over-supply and insufficient engine load. My recommended maximum continuous engine speeds are 2800rpm in calm water and 2600rpm in head seas. The engine has a very shallow torque curve, useful for powering displacement hulls.

Complete with the MS25A ’box, the Volvo Penta D2-55 marine diesel is 915mm long, 544mm wide and 692mm high, so it’s not bulky for its output.

Find marine engines for sale.

The Trade-a-Boat verdict

The D2-55 is Volvo Penta’s most powerful naturally-aspirated yacht-oriented marine diesel engine — and it’s built to last. It’s not high revving and four cylinders reduce vibration compared to three, though in fibreglass hulls it still needs flexible engine mounts and propshaft coupling to isolate vibration and give body flab a chance to survive.

This engine makes a great case for marinised industrial engines and its design features reflect Volvo’s long experience in making marine diesels. Contact Volvo Penta Australia for more information.

See more Volvo marine diesel reviews

Volvo Penta D2-55 marine diesel sea trials

Volvo Penta D2-55 specs

Engine type Four-cylinder indirect-injection marine diesel

Rated BHP/MHP* 52.3/53.0 at 3000rpm (prop shaft)

                                55.0/55.7 at 3000rpm (crankshaft)

Max torque 134.9 NM at 2400rpm

Displacement 2216cc

Bore x stroke 84 x 100mm

Weights 243kg (dry w/gearbox)

                253kg (dry w/sail drive)

*Brake horsepower/Metric horsepower or PS

See the full version of this review in Trade-A-Boat #478, on sale June 2016. Why not subscribe today?