Direct Injection in Two-Stroke Spark-Ignition Engines: Some Proposals and Researches

Several researches are on line dealing with the so called ‘new generation two-stroke engine’. In almost all of these the charge control by means of fuel injection has been proposed to overcome the well known fuel and lube oil consumption and the likely unacceptable pollutant emissions.

Direct injection in particular seems the method which guarantee the best results in avoiding the short circuiting of the fuel to the exhaust.

This paper summarises the experimental research carried on in the Ancona University both on high pressure mechanical and low pressure electronic direct injection systems and overlights their relative benefits and problems. Furthermore a new system using the “water hammer” phenomenon is proposed as a mean of achieving rather high injection pressures maintaining the simple manufacturing and low cost proper characteristics of two-stroke engines.