25cc HCCI Engine Fueled with Diethyl Ether

Abstract

This research forms part of an ongoing HCCI study at the SASOL Advanced

Fuels Laboratory to investigate and understand engine configuration and fuel

chemistry effects on combustion in HCCI engines. This project continues

from a previous project where a small Progress Aero Works (PAW) 6.5cc

high speed model diesel" aeroplane engine was found to operate in HCCI

mode with surprising ease and exibility. A 25cc, four-stroke, single cylinder

Honda GX25 engine, possessing 2-valves with an overhead cam and separate

oil sump lubrication system was used. This research aimed to provide insight

with respect to which engine characteristics such as size, heat transfer, speed

and fuel blending e_ects, play the primary role in operational di_erences

between the Honda GX25, conventional HCCI engines and the remarkable

operational exibility of the PAW engine.