Multifuel diesel power cube
A power cube module which contains a small indirect injection diesel engine. The engine is modified to allow reliable fuelling with a range of different oils. It does not need a second tank for diesel fuel to allow for reliable starting. It can be fuelled with a range of fuel oils and/or a mixture of oils
Indirect injection engines, with suitable injection equipment and some modifications, have been shown to run reliably with pure plant oil fuels, diesel, biodiesel or any mixture of these fuels. Although less common than small direct injection engines, most small (less than 1000cc) indirect injection engines have injection equipment that is suitable for reliable operation with these fuels.
The fuel oil is injected into a chamber in the engine cylinder head where heat and air turbulence initiates good combustion before the fuel is drawn into the engine cylinder. Indirect injection engines will provide good combustion with a larger range of oil fuels, compared to direct injection engines.
List of small indirect injection engines
Many of these engines are liquid cooled which creates greater complexity (cooling system required) but makes it easier to create a reliable multifuel engine and offeres the ability to fit a heat exchanger to provide the option of heat liquid output. Modules could then be used as combined heat and power units.
- Kubota offer a range of small indirect injection engines that, with suitable modification, have proven to operate reliably when fuelled with pure plant oil fuel 
- John Deere 755-3TNA72UJ 3cyl 878cc 14kW
- Some Iseki mini tractors are equipped with small indirect injection engines.
- Yanmar offers some small indirect injection engines eg 
- Perkins possibly offers some suitable engines.
Pure plant oil fuels
There has been much experimentation and practical experience in the use of pure plant oils as fuel for diesel engines. Pure plant oil fuels on Appropedia When engines with suitable modifications, operating and maintenance regimes and oils with suitable qualities  are used there has been shown to be little difference in engine longevity to when fuelling with diesel fuel. Engines modified to run on pure plant oil fuels can still be fuelled with diesel fuel.