From then on orders for engines reach the Moës Workshops. The men are dropping the activities related to the mill and devote themselves exclusively to the manufacturing  of internal combustion engines. From the start of the company in 1904, several hundred engines are built in the Moës workshops.

After getting an engineering degree after the armistice,  Paul Moës  joines his father and brothers and helps to further develop the Moës Workshops. In those  post WWI years the company name of Ateliers Moës-Freres is adopted. They design and built more petrol engines, diesel and semi-dieselengines (crude oil engines) and electric motors of various capacities, for industrial and  marine use. The Moës family make their reputation trough multiple innovations and  patented designs. In the 1920’s the man at Moës also  start to make narrow gauge locomotives equipped with a Moës semi diesel hot bulb engine. They are very exotic machines, to ease the transition from steam to diesel the loco has a steamloco appearance. Luckely a couple have survived in preservation.

In the 1930’s the companyname changes in  SA Moteurs Moës, Waremme. Thanks to the favourable industrial climate and development period, which lasted until 1940, business is very good. The factory makes internal combustion engines of all capacities, narrow gauge diesellocomotives for contracting and industry, underground diesellocomotives for mining and small standard gauge industrial locomotives.

Diminutive narrow gauge” locotracteurs” of the BL type, built from around 1935,  are common in the Belgian brick industry. They are equipped with the very simple B one cyinder, 2 stroke dieselengine. A number of them survived, mainly in Belgium but a few are preserved in France and Holland

In 1936, Moës developes the 4 stroke D type dieselengine with an anti flame device and exhaustfumes cleaning waterlock exhaustsystem specially developed for use in locomotives for underground duty's in the gassy Belgian coalmines.

Moës also makes small standard gauge locomotives, mainly for shunting duty's in factory yards.

As mentioned the Moës workshops are distinguished during a number of technical events by first prizes and medals. They acquire thereby a reputation  that extends far beyond  the Belgian borders. Moës engines and locomotives are sold in France, the Netherlands, Italy and overseas, to Africa and Asia.

To distribute the Moës products the company has several agents in Europe: Ernest Rigaux in Brussels, No less than 3 agents in France; J. Flory, Paris, V. Halleux, Chénée and Valere Grimonprez, Lille, Luciano Verrheeke in Madrid, Spain, Konenczny i Podgórski, Warshaw Poland and in Holland Eekels, Amsterdam and Nering Bögel in Deventer. The last company is not only advertising Moës C locomotives but also builds Moës patented hot bulb engines.

Again, for a second time in the history of Moës, war changes everything and between 1940 and 1945, Moës reduce their activities. Their focus is mainly on building agricultural tractors, marine engines type WM for coastal fishing boats and inland riverboats (the so called "Spits")

and underground type dieselloco’s for coalmining.

The Moës family are humanists and avoid deportations by maintaining employment. In some cases workers are employed fictiously. Moës employees are sometimes having the advantages of barter, being able to trade engineparts for bags of wheat, barrels of herring or a truckload of coal, which the staff is sharing…

In early post-war years the company benefits from the resumption of activity after the Liberation. The Belgian shipcompanys can buy Govermental subsidized Moës built shipengines to re-engine there inwater fleet.

Moës is re-enginening agricultural tractors and other machines with their D type engines.

But soon after initial uplifting results Moës suffers from the output of  military surplus: engines, generators and marine engines are sold for such low prices that they are impossible to compete with. Moës remain building narrow gauge diesellocomotives for underground and surface duties and they develop a new type of engine. 

But in 1960the coal crisis hits hard, causing closures of  Belgian coal mines. The export overseas is also suffering by strained relations between Europe and some of the colonies, now gaining their post-war independence. Nevertheless, Moës engines have a solid reputation and the company stays in business, in 1957 having their company name changed in Moës Diesel.

Moës Diesel is relying on partnerships with Hatz Engines (for over 50 years)  and is developing new activities. Moës Diesel is bought by  the Belgian BIA group in 1993 and sells high-quality generators and pumps built by Hatz and Tecnogen. Since the 15th of march 2013 the name Moës Diesel is changed in Moës Energy. From 1 october the same year the activities were transfered from Waremme to the grounds of the BIA group in Overijsse.

When researching the history of Moës on the internet a second Moës company is found, Moteurs Moës SA, housed in Andenne. When Moteurs Moës and Moës Diesel did become seperate companies is not clear at this moment, maybe allready in 1957. For Moteurs Moës SA , change comes in 27 september 2013 when the name becomes ABC Contracting SA, Andenne. ABC Contracting is part of the Ogepar Holding SA, Luxembourg.