Question 159Motor Plants - Assistant Engineer

The correct answer is D) Precision insert. Precision insert bearings are the most widely used for the main and connecting rod bearings of modern high-speed diesel engines. These bearings consist of a thin, precision-machined steel shell lined with a thin layer of a bearing metal alloy, typically an aluminum or copper-based alloy. The precision insert design provides superior load-carrying capacity, low friction, and excellent heat dissipation properties, making it well-suited for the demanding operating conditions of high-speed diesel engines. The other options, while used in some engine applications, are less common for modern high-speed diesel engines. Poured babbitt bearings (A) are an older design, while split roller (B) and steel-lined (C) bearings are typically found in lower-speed or less demanding engine applications.