Volvo Penta D1-13

The little things in life...

Released internationally in June 2005 and utilising a Japanese Shiibaura tractor engine base, the D1-13 is a compact and torquey diesel that suits keelboats to around eight metres. It would make an ideal re-power unit for a Top Hat 25 or Compass 28. The D1-13 meets US EPA Tier 2 exhaust emission regulations, to be introduced next year.

Developing 12.1hp (with 1hp equalling 746W), the twin cylinder indirect injection engine has a piston displacement of 510cc, a cylinder bore of 67mm, and a piston stroke of 72mm. The D1-13 has freshwater or heat exchanger cooling and the exhaust manifold is freshwater-cooled to reduce the possibility of the corrosion that can occur with saltwater-cooled exhausts. The freshwater cooling circuit is plumbed for hot water take off.

With its 23.5:1 compression ratio, hand-starting is definitely not an option with this engine, but at least cold-start glow plugs are fitted for easier starting in low ambient temperatures.

A lot of thought has been put into the design of the D1-13. The cylinder block and head are high grade cast iron and the crankcase has a rigid tunnel block design to reduce transmitted vibration. The chrome molybdenum forged crankshaft is statically and dynamically balanced with integral counterweights and the heat-treated pistons are cast from high silicon aluminium, with two cast iron chromium-faced compression rings and a single oil scraper ring.

The D1-13 develops maximum power at only 2800 to 3200rpm, compared to 3600 for the competition with the optimum cruising revs from 2000 to 2500. The standard 14V 115-amp voltage-regulated alternator still delivers 100 amps in the cruising rev range and its output is far above that of the direct competition. The seawater cooling pump is gear-driven while the freshwater pump and alternator are driven by a single vee belt.

The direct competition for the D1-13 are the Yanmar 2YM15, which utilises a Netherlands-built TNV industrial engine base, and the Kubota-based Beta Marine BZ482. Both engines have twin cylinders and indirect injection. The 2YM15 develops 13.8hp at 3600rpm from its 570cc powerhead, while the BZ482 develops 13.3hp at the same revs from 478cc.

Complete with mechanical gearbox, the 2YM15 weighs 113kg, with the saildrive version being 21kg heavier. The similarly-equipped BZ482 has a dry weight of only 89kg; however, the BZ482 is only available with a straight-output gearbox, which raises the engine’s forward end significantly higher than the D1-13, which has an eight-degree down angle at the output flange.

The D1-13 has a dry weight of 113kg with the down angle MS10A box and 112kg with the straight-output MS10L box. The 130S saildrive version is 13kg heavier. With the MS10A box the D1-13 measures 651mm long, 514mm high, and 488mm wide, compared to 613 x 463 x 528mm for the 2YM15, and 560 x 438 x 526mm for the BZ482.

So the D1-13 is a much lower engine – a real advantage when it’s mounted beneath companionway steps.

But the D1-13 really scores over the competition with its completely flat torque curve, from 1800 to 2800rpm. Admittedly, at 29Nm the peak torque output is not as good as the 2YM15’s 34Nm at 2400rpm, but having 29Nm on tap from only 1800rpm is great for manoeuvring in the tight confines of marinas.

At 1200rpm, the torque is 26Nm and at 27Nm at 3200rpm, so the D1-13 is ideally suited to yacht auxiliary usage where the power-to-displacement ratio is normally much lower than a displacement-hulled powerboat.

The BZ482 has a peak torque output of 28.8Nm at 2600rpm, so it’s way down on the Volvo Penta and Yanmar engines.

Based on a standard displacement hull prop power curve, at 1800rpm where the prop absorbs 2hp, the D1-13 consumes 0.7lt/h, while at 2400rpm where the 2YM15 produces peak torque, the D1-13’s prop absorbs 4.8hp with a fuelflow of 1.9lt/h, compared to 4hp and 1.1lt/h for the Yanmar, and 5.6hp and 1.2lt/h for the BZ482.

At 2600rpm and the peak torque for the BZ482, the D1-13’s prop absorbs 6.2hp with a fuelflow of 1.6lt/h, whereas the 2YM15 absorbs 5.2hp and 1.4lt/h and the BZ482 absorbs 6.8hp and 1.4lt/h.

At 3400rpm (90 below maximum continuous), the 2YM15’s prop absorbs 11hp and fuelflow is 3lt/h, compared to the maximum continuous revs of 3000 for the BZ482, where 9.4hp is absorbed and 2.5lt/h are used. The D1-13’s maximum continuous revs are 2800 where the engine uses 2lt/h.

The D1-13 produces maximum power at 3200rpm and consumes 3.1lt/h, compared to 3.5lt/h for the 2YM15 and 3.2lt/h for the BZ482 at 3600rpm. So for a nine per cent lower output than the BZ482 and 12 per cent under the 2YM15, the D1-13 uses three and 11 per cent less fuel respectively. But at 3600rpm, the Yanmar produces 27Nm while the BZ482’s output is down to 25.2Nm.

The D1-13 is available with three transmissions. The eight-degree down angle MS10A gearbox has a mechanical multi-disc clutch system and 2.35:1 or 2.72:1 gear ratios, and the straight-output MS10L is available with the same ratios. The 130S Saildrive has a dog clutch and 2.19:1 gear ratio.

The 130S Saildrive has cooling water intakes located just above the gearbox torpedo and the split zinc anode can be replaced without removing the prop. Gearbox and leg oil can be changed from inside the boat and Volvo Penta claims the three-bladed folding prop is effective when going astern.

The instrument panel includes a start button or key switch and an alarm for monitoring engine coolant temperature, engine oil pressure, and the alternator charging rate. A tachometer with hourmeter is optional.

For more details on the D1-13, contact Don Grimes at Volvo Penta Oceania on (07) 3902 5444, or email don.grimes@volvopenta.com.au