When the Saab 99 model was launched in 1968, it was powered by an inline-four engine sourced from the Triumph Motor Company in the UK.

[3] Sinclair presented the idea to Juhani Linnoinen, director of Saab-Valmet's factory in Uusikaupunki, Finland, during a meeting in the United States.

On his return home before Christmas 1987 Linnoinen assembled a small team to begin design of the engine.

[3] In August 1988 Linnoinen contacted Jouko Tommila, head of what was then the Valmet diesel factory in Linnavuori, Finland.

Another small team was assembled, consisting of Chief Engineer Mauno Ylivakeri, Head Designer Kalevi Salminen, Development Team Manager Timo Mäkinen, and Jarmo Kallio who was responsible for testing.

[4] The first engine assembled was run on a test bed for an extended time, with the only problem being a slight vibration of the crankshaft, which was solved by adding counterweights.

[3] After 6 months of testing in the Linnavuori district, during which at least one speeding ticket was received, the car was sent to Spain and Germany for additional trials.

[4] Reviews of the car were positive, and plans were made for a new factory to produce an anticipated 30,000 engines per year once approved.

Both cylinder heads were from the Saab B202 engine, but to arrange for intake ports on both sides of the vee to be inside the valley and exhausts to be outside, flow through one head was reversed; the intake ports became exhausts and vice versa.