Valmet engines were used occasionally in various Sisu models since 1969. The first version was a four-cylinder type 411 available for Kontio-Sisu LP-138. Later a horizontally mounted 611 was used to power the modular chassis SB-127 "Moni-Sisu" designated for buses and special vehicles. Also some 1980s produced S-type Sisu's used Valmet. Valmet was the dominant engine in military vehicles during the 1980s. They were dropped off from selection in the 1990s because the engines were not powerful enough and did not fulfill the emission regulations for on-road use.