• Nohab Polar F10, F20 and F30

Nohab Polar F10, F20 and F30

Spares suitable for Nohab Polar engines

Although these engines are now getting old (and in some cases very old), Simplex can still provide service engineers as well as a wide range of parts for Nohab Polar engines, including models:

  • F10:  Nohab Polar SF15 for a 5 cylinder, SF16, SF18, SF112 and SF116 with the last digit or two digits indicating the number of cylinders
  • F20:  Nohab Polar F25, F26, F28, F212, and F216
  • F30:  Nohab Polar F35, F36, F38, F312, and F316

These parts are sourced from leading specialist component manufacturers all of which are based in Europe, and are covered by our 12 month guarantee for major items.  This guarantee is supported by our £5 million product liability insurance.  The parts which we can supply include:

  • Reconditioning of cylinder heads (including repairs to cast iron cracks and corrosion pitting, but unfortunately no exchange heads are available). The cylinder heads can be returned as bare heads or built up with new valve guides, valve seats and valve spindles. Class certification is available if required.
  • Reconditioning of connecting rods and pistons and re-honing of cylinder liners
  • Cylinder head inlet and exhaust valve spindles
  • Inlet and exhaust valve seats
  • Valve springs
  • Valve guides
  • Valve collets
  • Fuel injection nozzles
  • Fuel injection pump elements (plungers and barrels)
  • Cylinder head gasket kits
  • Cylinder liners
  • Piston rings
  • Small end bearings
  • Connecting rod large end bearings
  • Main bearings


You can email us at webenquiries@simplexturbulo.com for further information or quotations on our range of Nohab Polar diesel engine spares.

Alternatively telephone us on + 44 (0) 1264 860186





The Nohab Polar F10-F30 is a series of engine models which was first manufactured in 1961.  Production of the F20 commenced in 1972 and the F30 in 1984. The last F30 left the factory in the mid 1990s.  All engines were single acting, four-stroke, trunk-type, compression ignition diesel engines. They were turbocharged and were manufactured primarily in Trollhättan, Sweden, although some engines were manufactured under licence in Glasgow. The bore size was 250 mm and the stroke 300 mm.

These engines were produced in different configurations both as in-line engines with three, four, five and six cylinders and in V form as eight, twelve and sixteen cylinders.  Curiously we are unaware of any nine cylinder engines being constructed. The normal way of designating these engines was:

  • For the F10:  Nohab Polar SF15 for a 5 cylinder, SF16, SF18, SF112 and SF116 with the last digit or two digits indicating the number of cylinders
  • For the F20: The “S” is normally removed and the engines are designated Nohab Polar F25, F26, F28, F212, F216
  • For the F30: the same designation is used as for the F20, ie F35, F36, F38, F312, F316

Initially the propulsion engines operated at 750 rpm but over the years as the new models were introduced this increased to 825 rpm and finally 900 rpm (1000 rpm for power generation using diesel rather than HFO).  Engine revolutions and power output per cylinder varied according to the application (propulsion or power generation) and the set- up of the engine.  As a guidance and using the propulsion figures with HFO the F10 produced 121 kW/cyl, the F20 kW/cyl and the F30 187.5 kW/cyl.  The outputs for diesel fuel applications were higher reaching a maximum of 209 kW/cyl for power generation.

The engines were very robust and there are still quite a number of F10 engines still running even though they are all over forty years old.  The engines were popular as propulsion units in the offshore industry, as well as in tugs, coastal vessels and other smaller craft and they were also used as power generating sets.