Performance Main Bearings STD - B Engine - SMALL THRUST

Our performance series main bearings are plenty strong for those high powered stroker builds without sacrificing long term durability for lots of street miles. These have all the best features built into them.

They are Tri-Metal construction, for maximum durability and longevity. Tri-Metal construction has been well proven and used since the 1950's. First developed and sold under the "Michigan 77" brand name, they were later bought out by Clevite, and then by Mahle. Tri-Metal construction is a well proven and mature method of bearing construction. It consists of a steel backing, which provides the primary structural ridgidity for strength and proper press fit rigidity of the bearing shell. Then, an intermediate layer of copper-lead alloy is bonded to the steel backing in a "clad" process, where high explosives are detonated on top of the two sheets of metals. This actually bonds the two metals together on a molecular level. This middle copper-lead layer helps to carry the bulk of the engine's load. Some lead is also mixed into the copper which acts as a solid lubricant, and tin is also added in for extra strength.

Finally, a very thin layer of leaded bronze/babbitt is applied, which offers excellent embeddability for any small debris or particles which may get into the oil. This provides seizure resistance as well as additional strength and anti-friction properties.

They feature a full (360 degree) oil groove.

They are also already narrowed and/or champhered as required to clear the larger radius on aftermarket and stroker crankshafts.

These have the smaller thrust surface, which was originally designed for 1973 and earlier engine blocks, but will fit engine blocks of all years.

These are Standard size for 2.625" main journals (B Engine.)