MWM Marine Diesels

MWM has long had an impressive reputation around the world for manufacturing reliable diesel engines for stationary, automotive and marine applications. For several decades the company's engines have been considered the alternative to Mercedes Benz diesels, particularly in Europe.

In 1883 Carl Benz opened his first engine factory in Mannheim, Germany and in 1922 Benz & Co divided the operation to establish MWM or Motoren Werke Mannheim to manufacture heavy-duty stationary engines with Benz in Stuttgart producing light-duty engines and automobiles.

In 1924 Benz GA merged with Daimler to create the Daimler-Benz Company manufacturing Mercedes Benz cars and trucks and two years later control of MWM passed to the Knorr Industrial Group (Knorr-Bremse), a German manufacturer of road and rail braking systems.

MWM opened is first office in Brazil in 1953 and commenced production of stationary and marine engines in 1956. Even then the marine engines had heat exchanger cooling for longevity.

Initially the OEM engines went into Fendt tractors in 1959 and since then MWM has produced OEM engines for Ford, Volkswagen, Nissan, Volvo Trucks, the Chevrolet S10/Blazer and other manufacturers.

The automotive connections have evolved steadily since 1959 and in 1971 MWM commenced supplying engines to FiatAllis and in 1973 equipped the Dodge D950 trucks with diesels. A year later MWM began a partnership with Ford to supply D-226-4 engines to the F-4000 series of trucks.

In 1977 MWM commenced production of the mechanically-injected D229 series of engines. In 1986 the Knorr-Bremse Group sold its MWM engine divisions in Europe and the US to the Deutz Group, retaining only the Brazilian operation. The Deutz Group continued to manufacture older MWM 225, 226 and 229 engine series, which were called Deutz-MWM. This arrangement remained in place until 2001 when Deutz was no longer able to use the MWM brand name on its products.

In 1993 Volkswagen and Ford introduced urban bus chassis' fitted with MWM 10 Series diesels and in the same year MWM celebrated 40 years in Brazil with 800,000 engines produced. Three years later MWM attained QA certificate ISO 9001 and the same year the VW Modulate Consortium was formed in Brazil with MWM managing powertrain assemblies. By 1998 MWM had produced one million diesels in Brazil and the company had attained QA certificate QS 9000.

In 2001 MWM commenced supply of the 4.2lt Sprint 6.07 TCA diesel for right-hand drive Ford F-250 cab-chassis vehicles exported to Australia and in 2005 MWM appointed Motores Diesel Australia as distributor for MWM stationary, industrial, agricultural, automotive and marine engines and replacement parts in Australia.

In 2005 MWM also joined the Navistar group and became known as “MWM International Motors”.

Commonality of parts and understressed outputs
Five D229 series of marine engines are currently available and they are direct developments the 229 series used in MWM's stationary engines. The three-cylinder D229-3, four-cylinder D229-4 and straight-six D229-6 are naturally-aspirated engines while the TD229-6 is turbocharged and the TBD229-EC-6 is a turbo-aftercooled engine. All have direct injection with 102mm cylinder bores and 120mm piston strokes. All engines develop intermittent and continuous power at a relatively low 2500 revs.

The engines are intermittently rated at one hour in every six for Wide Open Throttle operation or 16 per cent of the total time, far higher than any of the direct competition in these power ranges. The output rating is better suited to medium- or light-duty than pleasure craft boating and on paper this places the D229 series at a disadvantage against the competition, which is a shame as the torque outputs are impressive for piston displacement.

The 2.94lt D229-3 develops 55hp intermittent and 50.9 continuous (based on 1.0hp = 746 watts) and has a bobtail (sans gearbox) weight of 365kg, while the 3.92lt D229-4 develops 79.1 and 72.4hp and weighs 445kg. Both these engines would suit full-displacement cruisers and motorsailers in the nine to 12m range.

The 5.8lt D229-6 develops 118.0 and 108.6hp, weighs 570kg and would suit displacement cruisers to 14m. Its straight-turbo TD229-6 counterpart develops 143.4 and 130.0hp with a 15.9:1 compression ratio instead of 17:1 for the naturally-aspirated engines and weighing 625kg it develops 22 per cent more power for only ten per cent more weight, making it suitable in twin installations for semi-planing cruisers to 12m.

The TBD229-EC-6 develops 197.1 and 179.6hp, weighs 635kg and in twin applications could be used as alternative power to straight-turbo diesels such as the 5.9lt Cummins 220B in planing hulls to 9.8m. However, weighing 23 per cent more than the 220B, the TBD229-EC-6 is heavy for its power output.

Logical marine engineering
MWM's long experience in building diesel engines shows in the D229 series and all the engines have individual cylinder heads and removable cylinder liners capable of being replaced in-boat. The cooling system is indirect with heat exchanger, and both the raw- and freshwater circuits have gear-driven water pumps. Effective thermostats maintain constant operating temperatures regardless of cooling water temperature and the exhaust manifolds are watercooled with a water/air circuit for the turbo-aftercooled model. Spin-on oil filters are fitted and the turbocharged models have oil coolers. A single water-separating fuel filter is used in all engines.

The electrical system includes a 12V 3.0kW starter motor and 14V 65A voltage-regulated alternator and the instrument panel includes a tachometer, water temperature gauge and low voltage and oil pressure warning lights.

In coming issues, I will compare the D229s against their direct competition, but for more details on these engines contact Paul Chater or Chris Thomson at Motores Diesel Australia on tel (07) 3881 0068 or visit www.motoresdiesel.com.au