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Passenger car and heavy-duty diesel engine manufacturers recognize the need to ensure that engine oils maintain adequate low-temperature pumpability performance throughout their working life. For over two decades, the Mini Rotary Viscometer (MRV TP-1) bench test has been used to develop oils that have protected engines from oil starvation failure during cold weather startup. The test was created to measure the low temperature flow properties of fresh oils. During engine operation, a number of changes take place in the lubricant—both chemical and physical—that can influence oil pumpability. This paper presents a systematic evaluation of the role that various common lubricant additives play in affecting MRV viscosity and pour point and reinforces the notion that new oil MRV is not necessarily a good predictor of used oil pumpability. Presented at the STLE Annual Meeting in Calgary, Alberta, Canada May 7-11, 2006 Review led by Lois Gschwender

Babbitt temperatures in pivoted shoe bearings can be significantly reduced by offsetting the pad pivots in the direction of rotation. However, reverse rotation can occur in certain types of machinery under temporary or adverse conditions. The offset is then in the wrong direction and it becomes important to know if the bearing can withstand the reverse rotation operating conditions without damage. This paper compares pad temperature data from tests of a 152.4-mm, 60 percent offset bearing in forward and reverse rotation. The data indicate that the offset pivot bearing can run in reverse without damage for the operating conditions tested. Reverse rotation pad temperatures are hotter. Discussions towards the end of the paper address assessment of the data.