An Extended Jante Test Procedure for Two-Stroke Piston-Ported Engine Development

Two-stroke engine development has been occurring for many years. One of the main criteria affecting two-stoke piston-ported engine performance is scavenging,^{(4, 5, 10)} which is the process of using the incoming fresh air charge to purge the cylinder of exhaust gasses. Among the simplest test procedures employed to model scavenging air flow is the “Jante” test, developed by Alfred Jante⁽¹⁾. This test was developed primarily to develop port designs for engines operating at peak power and so gives results having limited use for engines operating over a wide range. By altering the operating procedure as discussed in this paper, the Jante test can be used to provide useful information about the engine's scavenging characteristics over a wider range of engine operation. This offers a powerful tool for determining a porting design's effect on scavenging, and therefore engine performance.