The effect of thermal expansion and elastic deformation on the performance of polyamide-copper journal bearings is presented. Three configurations of free open, free closed and constrained closed bearings are studied. The results showed that the load carrying capacity and maximum bearing temperature increase with increasing polyamide volume traction up to a value of 0.80 whereas the miminum oil film thickness and friction coefficient have the opposite effect. Furthermore, the increasing of journal rotational speed increases the load carrying capacity, maximum bearing temperature whereas the minimum oil film thickness and friction coefficient decrease. The open type bearing shows the economic best selectivity according to its smooth running at relatively higher polyamide volume fraction and rotational speeds.