Low Width Oil Control Rings for SI Engines

This paper presents 1.5 mm low width Oil Control Rings (2-piece and 3-piece). The current production 2.0 mm Oil Control Rings (OCR) is used as baseline to discuss the benefits of low width design. The width reduction increases the OCR conformability, allowing the reduction of the tangential force (Ft), hence lower friction. For 3-piece OCR, the reduction on Ft leads to lower stress and the improvement of the Ft thermal stability (supported by oven test results).

Engine test results are presented to compare the Lube Oil Consumption of 1.5 mm and 2.0 mm OCR, the OCR Ft loss after engine test and the effect of the Ft reduction in the 1.5 mm ring friction. Some challenges for handling and assembling of the narrower, 1.5 mm, OCR are also discussed.