P Series Main Bearings STD - B Engine

"B" (361/383/400) Main Bearings / Size: STD / Series: P / Material: TM-77 / Oversized Fillet Champher: NO / Oil Groove: Full .100" / Clevite's P series are the original staple bearing. They start with a hardened steel back for strength and support. Over that is a cast copper lead lining to provide the durability and support to withstand the loads of engine operation. Then a nickel plating is applied to prevent interaction between the copper lead and the final layer, a strong, extra thin (.001" or less) electroplated overlay of babbitt. Babbitt is a tin or lead based alloy with varying amounts of antimony, copper or arsenic which is designed to resist flaking and is very soft by nature. This helps to give the bearing embedability (the ability for stray particles to be "absorbed" by the bearing so they don't rip the crank journal to shreds), conformability (the ability of the bearing to "conform" or adapt to any out of spec surfaces or distortion) and resistance to both seizure and corrosion while still withstanding the high loads a performance engine can generate. Finally they are flash plated with a lead/tin mixture to help protect them. These bearings have high crush for better retention and their high eccentricity helps to accommodate any housing bore distortion. P series are not clearanced for aftermarket cranks with larger crankshaft fillets, although they will usually still work correctly, and any competent shop should be able to easily perform this operation to them if needed.