Heavy fuel engines

Heavy fuel system

Background information of our HF- Engines :

End of 2007 , 3W-Modellmotoren started with the R & D of Heavy Fuel Engines. 3 groups of technicians worked intensively 2 shifts per day to find a practical solution. Existing systems had been tried out with disappointing results which did not satisfy our demands.

Than a new approach was started.

  • Crankcase was pre heated for the cold start of the engine using cartridge heaters.

  • Air intake section and carburettor were modified

  • For 1-cylinder engines a special shaped muffler with integrated heat collector accepting cartridge heaters had been fitted

  • For 2 –cylinder engines 2 heat collectors ( 1 for each cylinder ) with cartridge heaters were fitted.

  • Engines were tested with an ambient temperature of +45°C in our test room. Starting and running without problems.

  • To simulate low temperatures , a 5Ltr. Tank with JET A-1 was stored in the deep freezer at -18°C over night. Cold start was no problem.

The combination of all the modifications was a break through of all efforts and hard work.

3W – Modellmotoren GmbH applied for patents of their HF – system in Germany and the USA. Registration numbers of both patent offices had been received in August 2008.

Standard available options

  • Break In Procedure using our program which can be modified to meet our customers specifications

  • Automatic Compression Release Valve starting with a cylinder capacity of 55ccm

  • Manual operated compression release valve

  • Engine Mounting Plate with a 4th. ball bearing , designed to accept a Bental or Sullivan alternator or alternator / starter unit.

  • 3W-210xiB2-TS-HFE
    3W-210xiB2 TS HFE  with special mounting plate to accept a Bental G-034 starter
  • 3W-210xiB2-TS-HFE
    alternator unit with 650W or a Sullivan unit with 1000W


  • Rear out put shaft standard, but not applicable with rear induction engines.

  • TS –cylinder ( Twin Spark ) starting with a cylinder capacity of 55ccm .

  • Painted cylinders , standard with CS engines

    Electric onboard starter

3W-157iB2 TS equipped with automatic compression release valves and
electric on-board starter

Impressum