A Study of Antiseizure Properties of Motor Oils in Crankshaft Bearings

Relative comparison of the antiseizure properties of motor oils in crankshaft main bearing was studied by observing the sudden temperature rise at the surface treated bearing, fitted in a Japanese 1.8 1 gasoline engine, using twenty-eight experimental oils and five commercial low viscosity oils. The results obtained are as follows.

1. 1.
   The antiseizure properties of the single grade oils depend directly on their viscosities, and higher viscosity oils have preferable property.
2. 2.
   In case of the multigrade oils, viscosity index improvers (VIIs) play an important role, and the antiseizure properties of the SAE 5W-30 oils vary from that of the SAE 20 single grade oil to the SAE 30 sigle grade oil depending on the VII contained.
3. 3.
   Detergent inhibitor packages and friction modifiers contained in the multigrade oils have a little effect on the antiseizure property.