Beta BV3300

Beta Marine is a Gloucestershire, UK-based company that specialises in marinising Kubota tractor and industrial engines. All of its models are naturally aspirated and from 43-90hp all engines develop maximum outputs between 2600 and 2800 revs, way below that of other manufacturers' diesels in their power ranges.

In Trade-A-Boat we've already reviewed the less powerful engines including the unusual five-cylinder 2.8lt BF2803, which develops 62hp and uses components from the four-cylinder 50hp BV2203. The base engine is also marinised by another company and in straight turbocharged form develops 85hp and is the standard engine for the Arvor 20 fishing boat.

But for its more powerful engines Beta goes back to four cylinders. The BV3300 is the smaller of two recently-released models and has the same indirect injection with glow plug cold-starting of its smaller counterparts.

Understressed for its output
The BV3300 develops 75hp at 2600rpm from its 3318cc powerhead and has a cylinder bore of 98mm and piston stroke of 110mm. Complete with mechanical Hurth gearbox it weighs 390kg or with a hydraulic PRM 260 gearbox 414kg, so it's a fair lump of engine for its output and really only suited to pure displacement-hulled cruisers.

Unlike its smaller counterparts it produces massive torque at low revs, peaking at 250Nm at only 1400rpm. Even at 800rpm it produces 235Nm, tapering off to 218 at 2600rpm.

Based on a standard prop power curve the fuel consumption is very reasonable for its output and at 1000rpm, where the torque produced is 240Nm, the BV3300 consumes only 6.0lt/h. At 1400rpm it's 8.0lt/h and at 1800rpm, again where 240Nm is produced, the consumption is still only 10.0lt/h. Increasing the revs to 2200 where 232Nm are produced the consumption is 12.1lt/h but at 2600rpm it's 15.9lt/h, so really 2200 revs should be considered the maximum continuous for this engine. At these revs the BV3300 can still develop 68hp.

Compared to the Yanmar's two-litre straight-turbo 4JH3-TCE, which develops 73.7hp at 3800rpm, the BV3300 not only produces substantially more torque but is also more economical. Although having direct injection, which is usually more fuel efficient than indirect, the Yanmar's straight turbocharging results in much higher combustion chamber air temperatures which reduce the density of air being forced in and subsequently the fuel efficiency.

Because of the straight turbocharging (Yanmar's turbo-intercooled versions of this engine are more fuel efficient) the 4JH3-TCE produces only 170Nm at 2800rpm, while at 3800rpm its uses 18lt/h.

Volvo Penta's 2.2lt turbo-intercooled D2-75 is more fuel efficient and develops its maximum output of 73.7hp at only 3000rpm. However it has indirect injection which in my opinion is not the way to go for turbo-intercooled engines because the increased air pressure being forced in can stress the cylinder head between the injectors and pre-combustion chambers. The D2-75 produces a maximum of 212Nm at 1800rpm with 209Nm at 1600rpm (compared to 245 for the BV3300) and 210 at 2000 (compared to 238), dropping off to 200Nm at Volvo Penta's recommended cruising rev limit of 2500. At these revs the BV3300 produces 222Nm.

At the maximum continuous revs of 2600 the D2-75 consumes 10.3lt/h but at 3000rpm this jumps to 17.7lt/h, so the engine still can't match the BV3300 for overall efficiency for output.

But having relatively small displacement powerheads the 4JH3-TCE and D2-75 are much lighter. Complete with gearbox the Yanmar weighs just 260kg and the Volvo Penta 258kg, compared with 390kg for the BV3300 with a mechanical Hurth box and 414kg for a hydraulic PRM 260 box. The latter box would be my choice for displacement cruisers because it provides more control when manoeuvring, although if the engine was fitted in a motorsailer the engine would need to be left in gear when sailing to prevent gearbox damage from insufficient lubrication.

The Yanmar and Volvo Penta are also more compact, the 4JH3-TCE being just 891mm long, 563mm wide and 619mm high and the D2-75 measures 917 x 544 x 891mm, both engines including mechanical gearboxes. In comparison the BV3300 measures 1078 x 550 x 770mm.

Sensible engineering
Beta Marine puts a lot of thought into marinising its engines and the BV3300 is no exception. The base engine has a cast iron cylinder head and block and Kubota's 'three vortex' combustion system to reduce exhaust emissions, while the sea water cooling pump and the camshaft for the pushrod-operated valves are gear driven.

Beta's integral heat exchanger manifold system has a cupro nickel tube stack, phosphor bronze end caps and replaceable zinc anode. Alternatively for cruisers operating on shallow, silt-laden waterways Beta offers thermostatically-controlled keel cooling, the system used with great success in Halvorsen hire cruisers operating on Sydney's Hawkesbury River. If a PRM hydraulic box is fitted it's water-cooled to ensure reliability under load.

Beta fits easily-serviced fuel and oil filters and the fuel lift pump is mechanical. A brass sump pump is standard and the engine oil dipstick is located at the top of the engine, while the dry-filter air intake is mounted above the rocker cover to ensure a clean supply of air. A heavy-duty power take-off is provided on the forward pulley system where a vee-belt drives the alternator (mounted well up the block) and freshwater cooling pump. The 12V 65A alternator has voltage regulation but for greater power drains a 100A alternator is available. Engine installation angles are up to 15 degrees static and 25 heeling and a flexible mounting system with heavy duty feet is fitted.

The instrument panel comprises three warning lights (oil pressure, high cooling water temperature and no-charging) along with an audible alarm and a tacho and hour meter but the Type C panel includes oil pressure and water temperature gauges and would be my choice because it enables operators to closely monitor the engine underway.

For more details on the BV3300 contact Glenn Townsend at Beta Diesel Australia on (02) 9525 1878.