King Engine Bearings MB7719SI SI-Series Main Bearing Set AMC Jeep 242ci 4.0L

The King Engine Bearings MB7719SI is a SI-Series bimetal main bearing set designed for the AMC/Jeep 242ci 4.0L Power-Tec inline six-cylinder engine.

SI-Series Bimetal Construction:

• Aluminum-silicon alloy material — strengthened with 2.5–3% silicon for medium-load engines and nodular cast iron crankshafts
• 100% lead-free construction for environmental compliance and safety
• Improved oil clearance tolerances — helps maintain OEM clearances over engine life, reducing operating noise, vibration, and excess oil flow
• Enhanced wear resistance — silicon particles condition journal surfaces by rounding off high spots on the crank, reducing friction and related wear
• Reduced wall variance — unplated bimetal construction achieves up to 40% tighter wall variance compared to tri-metal overplated copper-lead bearings
• Half-groove design for proper oil distribution
• Bull's Eye Tolerance™ Technology — King's proprietary precision machining and computerized wall thickness monitoring for consistent, accurate fitment

King Engine Bearings has specialized exclusively in engine bearings since 1960, applying knowledge gained from aviation and motorsport applications to every aftermarket bearing produced. The SI-Series is the preferred OE-replacement material used in many factory engines and is purpose-built for gasoline and diesel engine rebuilding applications with OE crankshafts.

Available in standard and multiple undersize options.