Ring Dynamics in a Diesel Engine and Its Effect on Oil Consumption and Blow by

Measurements of cylinder and inter-ring pressures and top ring axial movement were made on a 4-stroke V8 diesel engine running at full power, in order to understand differences in observed oil consumption and blowby for 5 different ring and piston combinations. In each case the parameters were also calculated using a newly developed computer program which combines the effects of ring lift and twist, inter-ring gas pressures, ring profile and tension and liner finish on ring hydrodynamics and gas flow. Encouraging correlation was shown between measured and predicted results.