Oil and Ring Effects on Piston-Ring Assembly Friction by the Instantaneous IMEP Method

H. Mehmet Uras; Donald J. Patterson

doi:10.4271/850440

1985-02-01

Oil and Ring Effects on Piston-Ring Assembly Friction by the Instantaneous IMEP Method 850440

This paper describes the friction characteristics of a 1.8 Litre J-car piston and ring assembly as influenced by oil rings of conventional design, but of varying tensions. In addition, the piston-ring assembly friction characteristics are reported for a set of oil viscosities ranging from 2 to 20 cSt with and without a molybdenum friction modifier. Multigrade oil results are shown also. Finally comparisons are presented between changes in friction measured by the Instantaneous IMEP Method and those measured by the dynamometer for the engine as a whole.

Our results show large differences in piston-ring assembly friction as oil ring tension was varied. However, these differences became moderate after the oil ring broke-in. Both high and low oil viscosities increased piston and ring assembly friction. The friction modifier was most effective with a mid-range viscosity and provided virtually no benefit at viscosity extremes. The Instantaneous ÎMEP Method correlated well with dynamometer values under motoring conditions. The correlation under firing was relatively poor.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Digital $37.00 Print $37.00

Preview Document

We also recommend:

Standards

SAE Mobilus®

Publications

News

Events

Professional Development

A World in Motion (PreK-12)

Participate with SAE

SAE Membership

Donate

Oil and Ring Effects on Piston-Ring Assembly Friction by the Instantaneous IMEP Method 850440

SAE MOBILUS