Traditional bearings have three layers: steel, copper-lead, and thin babbitt overlay (only 0.0005" to 0.0008"). JEGS Main Bearings in a Performance or High-Performance series have two layers: high-strength steel and bonded silicon, tin, and copper in an aluminum matrix (0.015" thick). Because an alloy, properties are maintained through its entire depth to deliver consistent, reliable output. Additionally, micro-fine machined High-Performance Bearings have chamfered oil holes and offer a tri-metal copper, lead, and nickel version for some applications. Bearings are sold in sets for Chevy and Ford applications.
High Load Capacity
Aluminum silicon bearings withstand the stress of high-performance engines. JEGS Bearings are made from the same metallurgical alloy so cars that have standard bearings benefit from this alloy used in race engines.
This alloy's melting/fatigue point is 450°+ F (100° more than the thin babbitt overlay of tri-metal bearings). This means extra protection against localized overheating due to misalignment, detonation, overloading, loss of coolant, etc.
More than half of engine bearing failure is caused by metallic particles that scratch crank journals and weaken or tear thin bearing overlays. Because aluminum silicon overlay is much thicker than babbitt in tri-metal bearings (0.015" vs. 0.0008"), it provides 18 times more embedability to trap particles to prevent crank journal scratches. This is especially true for particles over 0.0004", which cause most of the damage.
The thicker aluminum silicon layer allows bearings to better conform to problems, such as metal-to-metal contact due to misalignment. Greater conformability also means fewer bearing failures.
Control of Wall Tolerance
Bearing-to-journal clearance is affected by several factors. We've alleviated concerns about inconsistent shell-to-shell bearing wall thickness by using statistical control methods to minimize wall thickness variation. JEGS Engine Bearing thickness varies no more than 0.00010". Other manufacturers produce bearings with wall thickness at the crown that varies as much as 0.00025".