Cam Bearing Set STD SH21S CLSH21S Suit Ford Flat Head 1939-53 239, 255 ci FORD FLAT HEAD CAM BEARINGS Heavy Duty Cam BearingsB-1Steel back tin or lead base conventional Babbitt (nominal .020" thicknessIn the last decade or so engine development has increased dramatically. Each time an existing engine is revised or a new engine is developed, it pushes the limits of what its predecessor could produce both in horsepower and torque as well as fuel efficiency. With these gains, comes an increased load on the internal parts of these engines. One of these parts that are continually asked to perform under greater and greater pressures is the cam bearing. In engine configurations such as V6's and high RPM 4 cylinders, the cam bearing is a vital link along the path of the engines oiling system. If a cam bearing wears out prematurely the engine loses some of its oil pressure, which we all know can lead to premature engine failure. Other problems, which can be caused by premature cam bearing wear, are excessive cam lobe runout, improper timing, and generally poor running conditions. This is where strength and durability become key issues. This is why, in most applications, the O.E. manufacturers have turned to higher performing cam bearing materials. Traditional Babbitt can only withstand up to 1800 psi. Clevite's AL-3 material can withstand up to 5000 psi. Quite a difference. When trying to adapt Babbitt to an application that requires a more durable material, extra oil grooves are needed on the outside diameter of the bearing itself to help get oil to the rest of the engine. This only addresses the oil starvation symptom inherent to the real problem of premature wear. All of the other symptoms that were listed above still occur with the right material for the job, such as Clevite's AL-3, these extra oil grooves aren't needed at all. In fact this gives more bearing contact area to the block to help in transferring heat away from these parts and prolonging bearing and engine life. Remember, when strength and durability is part of the question, Clevite is the answer.On certain modified performance applications Clevite also offers a TriMetal cam bearing material (TM-1) that provides even greater strength and durability. These cam bearings are able to withstand loads in excess of 8,000 psi, while providing surface characteristics that are very forgiving and conformable.
