History

Translation of the book "From Munktells to Valtra"

THE 50 FIRST YEARS OF VALMET DIESEL ENGINES

The State Aeroplane Works at Tampere, today known as Kalmar procured a safer place for engine manufacturing of military fighters outside Tampere. The place was found in the municipality of Nokia, an ancient fort on a hill. The stony location also gave possibilities to hide the most important operations inside the rock.

The production started in 1943, which was too late for the delivery of aircraft engines. The only military related products were some component deliveries for a fighter "Myrsky" (Storm). After the war, the company manufactured civilian products like Atlas Copco compressors, June Munktell marine engines and Scandia diesel engines.

Diesel engine production was started at the plant in 1946. The first design of Linnavuori factory was the family 15, consisting of a swept volume of 1.5 litres per cylinder. The most successful model of the family was an eight-cylinder 12-litre version Valmet 815 D developing 180 hp DIN. It was the power source for the light people carrier of the Finnish State Railways (VR). The commuter train was manufactured by Valmet Aircraft Factory, Tampere. For some generating set purposes the engine was turbocharged up to 250 hp by two turbo units, one for each four cylinders.

It is worth mentioning that Valmet manufactured direct injection and even turbocharged diesel engines as early as at the beginning of the 1950's. How many of our competitors can show a similar background?

There was an era of two cycle engines like the petrol-driven inboard engine "Vire". The cumulative production of this engine exceeded 14 000 units. Another product was a light two-cycle air-cooled petrol engine, called Rapidex. It was used by fire brigades and the first pioneers of Scandinavian snowmobile manufacturing.

Alongside the original Valmet designs, a great many marine diesels were built under the licence of Burmeister & Wain, Denmark.

Tractor engines

The first tractor engine of the Linnavuori factory was the petrol/kerosene powered 1.5 litre engine of the "Barbed Wire Tightener", marked as Valmet 4035 B/P.

The diesel era of Valmet tractors started in 1957 with the unveiling of the model Valmet 33 D with Valmet 309 diesel engine. The concept of this engine was a total success. In fact, the company still uses the concept in its engines, including liquid cooling, direct injection and wet replaceable cylinder liners.

Tractors needed more power. The first four-cylinder diesel engine, 411 A 4.2 litres and some 77 hp SAE, was introduced together with the big Valmet 80 in 1963 (later called Valmet 864). The next application was the revolutionary Valmet 900.

Valmet was the first to turbocharge a four cylinder engine. The turbocharged version 411 AS came to the market in 1969. The first applications were a Valmet 1100 tractor (rating 115 hp SAE) and Sisu K-138 BIT, a delivery truck (rated 125 hp SAE).



Larger clientele

In 1974, the diesel engine factory celebrated the birth of its 50 000th diesel engine. The new generation of engines, the 11 range was introduced one year later. Top model of the range was a six-cylinder turbocharged version but as a spin-off, a great three cylinder 311C/CS and a four cylinder 411C/CS version were taken into production in the late 70's.

The Finnish combine harvester manufacturer, Sampo-Rosenlew fitted a Valmet engine to their products in early 70's. The Danish competitor Dronningborg joined the team and was an excellent reference to the high-horsepower six cylinder engines.

Sisu Trucks was a significant customer for the turbocharged six cylinder engines powering the product family Karhu-Sisu (karhu=bear). Maybe the most famous application of Valmet diesels were the Sisu Pasi armoured people carriers used by many Scandinavian and Central European countries for peace-keeping purposes of the United Nations.

Naturally, Valmet Logging and many other industrial equipment makers in entire Scandinavia adopted Valmet diesels. Parallel to diesel engine manufacturing, Linnavuori made power generating sets for example, the patented V arrangement was favoured by the Federal Mail of Germany.

Valmet diesel is very well known in the Arab countries. There are more than a thousand stationary engines for irrigation purposes on that peninsula. As a marine engine Valmet is highly respected.



Heart of Volvo BM Valmet Tractors

Valmet acquired the tractor operations of Volvo BM in 1979. The tractors of Volvo BM Valmet range from 65 to 95 hp were powered by Valmet diesels. The next "D" generation of 11 range diesels included modifications in the fuel injection system and use of Bosch in-line pumps in 311D/DS and 411D/DS diesel engines. High torque increase made the three cylinder models 505/805 "re-born BM Boxers".

According to the agreement with Volvo BM, VBM was to favour three and four cylinder Valmet diesels in VBM products and vice versa, Volvo BM Valmet six cylinder tractors were to be fitted with Volvo engines. This principle of the agreement, however, did not materialise.

Therefore, the six cylinder model 905, 105 hp DIN got a Valmet 611 D 6.6 litre naturally aspirated engine instead of the 5.5 litre Volvo D60 engine.

The smallest Volvo BM Valmet tractors were unveiled in 1985. The well-proven 2.7 litre engine was modified to yield 53 and 61 hp; both versions of Valmet 309 engine were turbocharged DS versions.



Big six cylinder 612

Big combine harvesters and various Sisu vehicles needed more power. Therefore, the engineering department of Valmet Diesel decided to develop a heavy-duty 7.4 litre six-cylinder engine. It was called Valmet 612D/DS. According to the earlier type marking system, the two last digits gave the swept volume of one cylinder in desilitres - 12 referred to 1.2 litres per cylinder.

The development process of this power unit spawned off some major innovations like the mid support of the cylinder liner. The cylinder liner stays in conformity with the piston, minimising the oil consumption which in turn lowers the particulate emissions. Thanks to the mid support, the vibrations of the cylinder liner are reduced, eliminating the risk of cavitation. Also the cooling of the cylinder is more efficient because the main part of the cooling liquid is circulating round the upper part of the cylinder liner.

The product was well received on the market. Not only were previous customers happy but Linnavuori got new customers like the MF tractor plant in Beauvais, France in 1988.



The new generation

Valmet signed a letter of intent with Steyr-Daimler-Puch AG in 1986. One of the objectives of the agreement was to create a new generation of diesel engines and share the production between Finland and Austria. Unfortunately, at the final stage of this project Steyr was forced by her major shareholder, Kreditanstalt Bank, to cooperate with the German KHD (Deutz), which in turn was heavily supported by Deutsche Bank.

Valmet decided to stay outside this forced co-operation pushed by banks. Engines were the core business of Deutz and a deeper co-operation would have jeopardised the future of Valmet Diesel.

As predicted, Steyr lost engine manufacturing in favour of Deutz. In this situation Valmet decided to launch the new 20 range of Steyr-Valmet diesel engines into production in Finland. Fortunately, the basic design of the engine was tested and many preparations for the production were already made. The parts meant to be manufactured in Austria were adopted to the production process of Linnavuori in a record time.

The new Valmet 20 generation became ready for the new tractor family of the 90's. The objectives set at the beginning of the development project were well met. There was less noise and emissions, fuel economy was better and modern design gave an excellent basis for further development.

Later, Steyr turned back. The big tractor range of Steyr was based on MF/Mega 8600 concept. The models 155, 170 and 190 hp - all powered by Valmet engines - were launched in 1993. Two years later, Steyr introduced a new range of 105-145 hp with Valmet engines.



Valmet diesels in Brazil

Valmet Diesel was organised as a part of the tractor group in 1991. This was a beneficial decision to developing the business further. When Valmet established the tractor plant in Brazil in 1960 it was not possible to manufacture their own engines because there were some specialised engine manufacturers in the country, enjoying development programme from the government. Therefore, Valmet had to select the best possible partner, which was MWM.

The import duties of Brazil were lowered at the beginning of the 90's. In this situation, the first 50 Valmet engines were shipped to Valmet do Brasil. The engines were fitted to the sister models of the "Nordic tractor". The Valmet powered versions were marked with the letter S. The models 885S and 985S got the engines 420 D/DS and 1180S 620 D respectively. The "original" engines quickly gained very good reputation.

VdB and the experts of Linnavuori prepared the sourcing of local standard parts and the assembly of engines. The first Valmet diesel was assembled in Mogi das Cruzes in December 1994.



Sharing the interests

MWM became very worried because of the entry of Valmet diesels to Brazil. However, the target group for the original engines were four cylinder turbocharged and six cylinder models. Good relations with an old partner were maintained by agreeing that MWM Motores Ltd would supply engines mainly under 85 hp while the higher hp area is reserved for Valmet engines. This agreement was signed in August 1995.

The Brazilian engine version had some differences. Due to the weather conditions, the engine block heater and thermostart were left out, and because of the local component market, certain versions were fitted with CAV rotary injection pumps and Bosch electric equipment.



Even bigger sixes

The heavy-duty 612 engine was too heavy or expensive for many purposes. The Diesel factory therefore decided to develop it further and make a 7.4 litre engine based on the 6.6 litre 620 DS. The displacement was increased by extending the stroke from 120 mm to 134 mm. Otherwise, the new product 634 shared the majority of components with the 20 series.

Massey-Ferguson had received positive comments on Valmet diesels from the customers as a result, decided to extend the model range powered with Valmet to power ratings 160, 180 and 200 hp in 1994. The 200-hp version was powered by the new Valmet 634-DS.

The engineers at Linnavuori developed the 612 further. The result was the Valmet 645 diesel engine, unveiled in the Agritechnika Show in Hannover, in 1995. This time, both bore and stroke were increased to 111 mm x 145 mm, giving a displacement of 8.4 litres. The power rating of an intercooler version was over 300 hp with a good potential to 400 hp in combine harvester use. Just for curiosity: Valmet diesels had a 13 % market share of the European combine harvester power units. Main customers were Sampo-Rosenlew and Dronningborg Industries.

The engine factory at Linnavuori.
A straight eight-cylinder diesel Valmet 815 D, designed by Linnavuori.
The Rapidex fire engine.
The small two-stroke petrol engine was designed for powerboats with in-board configuration. The accumulative production of "Vire" engine came close to 15,000 units.
The first tractor engine was a four cylinder 1.5 litre Valmet 4035 B/P. It had an L-form cylinder head design and used petrol or kerosene.
The three-cylinder diesel engine Valmet 309 D had the concept of today as early as in 1957. It had liquid cooling, direct injection and wet, replaceable cylinder liners.
The four cylinder Valmet 411 A got a turbocharged version 411 AS in 1969.
The factory returned to bigger engines in 1974 when the production of the six cylinder 611 C range was started in the new premises. The three and four cylinder versions were later on standardised with the six-cylinder model.
In 1979, Valmet was the first manufacturer in the world to take the pressure wave Comprex supercharger of Brown Boveri & CIE into serial production. The engine version was called Valmet 411 CX, 110 hp.
 
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