page_title: Sisu Auto
section_title: Engines
hierarchical_section_title: Sisu Auto / History / Key components / Engines
caption_attribution_description: English: Sisu SA-5 engine made under licence of Hercules (original model name AMG).
context_page_description: Sisu Auto is a truck manufacturer based in Raseborg, Finland. Its name comes from the Finnish word sisu meaning guts, grit and determination.
  Sisu Auto has a subsidiary company, "Sisu Defence", producing high mobility tactical vehicles for military use.
context_section_description: The first Sisu's were powered by Volvo supplied Penta engines. The 1934 presented Sisu SO-models were equipped with Finnish produced Olympia engines which turned out to be too weak and unreliable. Therefore, the power source was changed again already in 1935 launched SH-series which was powered by American Hercules engines. In 1937 Sisu became available with Hercules diesel engine but they were not sold many yet. In the following year another American engine, Buda was added in the selection - this Sisu-series was called SB respectively.
  During and after the Second World War SAT produced Hercules side valve petrol engines under licence. The initial model was called AMG of which military designation was SA-5; it was also produced by Tampereen Pellava- ja Rauta-teollisuus as Tampella 6000. It was followed by upgraded versions AMH, AMA and AMI. Other variants were marine models VMG and VMI Speedmarine and stationary engine PMG. PMG's were used on winches and compressors delivered to Soviet Union as war reparation. The last SAT-produced Hercules based engine unit was mounted on the first Sisu KB-45 military lorry prototype in 1964.
  In the 1950s the lorry and bus model selection diversified heavily and diesel engines became more common pushing aside the self-produced petrol engines. For a short time in late 1940s Hercules diesels were used, but as soon as their production ended, SAT was forced to find new power options. West German Henschels proved sturdy engines, but their power-to-weight ratio was not good, and moreover, the vehicle structures suffered from the heavy engine. Henschel was finally dropped off from the selection because the weakening Finnish mark in relation to German mark made them too expensive.
  The first Sisu with British made Leyland engine came already in 1948. From the early 1950s Leyland was virtually the standard power source in Sisu's for during the following three decades; about 30 different types were in use. Some of the types were very robust but also technically failed units appeared with repeating problems; the Leyland O.801 V8 diesel is particularly mentioned as one of the worst. By the early 1970s Leylands had remained too weak for the increased permissible vehicle total weights in Finland.
  Rolls-Royce diesels came into selection in 1955 in Sisu K-36, the strongest flatbed hauler in Finland at its time. The 250-hp engine type was C6SFL. Later the same engines were used in some dumper trucks and in 1961 in K-50SS, the up-to-date largest automobile built in the Nordic countries. In 1966 SAT produced vehicles with 300-hp Rolls-Royce diesels; the Sisu K-142SS was one of the most powerful trucks in Finland and advertised as "the king of the highways". The Rolls-Royce Eagle engines became to the selection in 1967. The 1970 introduced R- and M-series had initially the 282-hp Eagles; a number of variants with different outputs were presented after.
  Cummins was used for the first time in 1966-1968. The model was Cummins Vale V8 which caused a lot of warranty costs. Next time Cummins came into use in 1978; the 6-cylinder engines gained soon a good reputation pushing aside the other engine makes and Cummins became almost an exclusive engine supplier for Sisu trucks. It maintained its position until the 1990s.
  In 1997 Renault started a component supply partnership with Sisu. In parallel with Renault Engines, American Mack came to the selection. The 2002 introduced Sisu with 630-hp Caterpillar C-18 engine raised Sisu to new level of power. For a while Sisu had in its selection most powerful serial produced lorry of Europe.
  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 powerf
caption: Sisu AMG, a licence-built Hercules JXC.
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