Petrol-paraffin engine

The Milnes-Daimler motor bus of 1904 (based on the Cannstatt Daimler lorry), operated in London by Thomas Tilling, ran on either petrol or paraffin, but for starting the engine, or frequent stop-start work, petrol continuously was the preferable option.

A petrol/paraffin engine tends to run hotter whilst burning paraffin, and so the cooling system must be sufficiently robust.

Being slower burning, the paraffin requires the longer combustion period that a four-stroke engine can provide; so two-stroke versions are rare.

The fuel used in petrol-paraffin engines was known as Tractor vaporising oil (TVO) in the United Kingdom and as Power kerosene in Australia.

It was a 70 bhp petrol-paraffin engine, but using solid naphthalene rather than paraffin, simply as a cheaper fuel.

Waterloo Boy tractor produced by John Deere , 1919-1920. The tractor has a small petrol tank, used for starting the engine and a larger tank (at the front) for paraffin to run it
Paraffin (kerosene) tank on Waterloo Boy tractor
A cutaway view of the intake of the original Fordson tractor (including the intake manifold , vaporizer , carburetor , and fuel lines).