LV66-s and LV68-s
When Volvo started the sales of trucks in 1928 it immediately became profitable, but not only for the customers but also for Volvo.
It was obvious to the management, Assar Gabrielsson and Gustaf Larson, that profitability was better for production of heavy-duty commercial vehicles than for passenger cars and small trucks. These light-duty vehicles sometimes had to be sold at loss due to fierce competition from manufacturers of (mostly American) cheap cars.
Larger trucks with special truck-components
In the 1930's, the major Swedish truck and bus manufacturers were Tidaholm and Scania-vabis. The number of trucks manufactured per year from each of these stall manufacturers seldom exceeded one hundred. It was, of course, tempting for Volvo to start the production and sales of large trucks.
In 1929 (when the LV Series 3 was presented, and design capacity was available for larger vehicles) Volvo started the design of larger trucks; the LV66- and LV68-series. Previous trucks had been based to a large extent on components which were used also on the Volvo cars. For the new trucks (the first heavy-duty vehicles made by Volvo) stronger components were needed. The design of special truck-components, including engine, gearbox, rear axle and chassis components, was started.
Choosing the right engine
In the early stages of the planning for the new trucks, two different engine configurations were evaluated', either a six-in-line or a straight-eight. In the end, the more traditional six-cylinder engine configuration was chosen, in combination with an unsynchronized four-speed gearbox. Since the new trucks series spanned a rather large GVW range, in two- and three-axle versions, alternative rear axles were offered, with either single (for LV68/69/70) or double (for LV66/LV67) reduction.
The demanding task of snow ploughing
The new LV66- and LV68-series of trucks were introduced in 1931. They became quite popular, especially in the lighter version LV68/69/70 (the three different designations indicated different chassis wheelbases). The heavy-duty LV66/67 types did not obtain the same popularity, for two reasons. The number of heavy-duty trucks sold annually was limited in those days, and the 75 bhp overhead-valve petrol-engine was not powerful enough for snow ploughing during severe Swedish winkers, a rather important source of income for the truck owners in those days.
Initially, two-axle trucks were introduced, but in 1933 super- heavy three-axle vehicles were presented. These were used e.g. as tanker trucks or heavy-duty construction vehicles.
The Hesselman engine
Due to the fairly high fuel consumption, customers wanted to decrease the fuel cost. This was the reason why Volvo introduced the 'Hesselman' engine. This intelligent engine alternative to the petrol engine, and to the diesel engine, was designed by the Swedish inventor Jonas Hesselman.
The Hesselman engine was based on the petrol engine and had the same (1ow) compression ratio as the petrol engine, but thanks to an injection pump in combination with spark plugs of a powerful type it could be run on diesel fuel (or any other fuel). This engine became quite popular, but was not at all as efficient as the high-compression diesel engine. If run very hard and by an experienced driver, however, it was a good and reliable power source.
From truck to bus
The LV66- and LV68-series of trucks were used for many different transport applications. The LV70 also played a major role for Volvo as a bus manufacturer. Many LV70 trucks (sometimes in lengthened version) received a bus body. In 1932 a special 'LV7OB' version was developed. This became something of a standard bus in Sweden.