More than half of engine bearing failures are caused by metallic particles which scratch crank journals and tear or weaken thin babbitt overlays such as in the tri-metal bearing.

Since King’s Alecular bearing layer is much thicker than the babbitt overlay (.015" vs. .0008"), it provides eighteen (18) times more embedability than a tri-metal bearing to catch and hold particles so they don’t scratch the crank journals. This is especially true for particles over .0004" in diameter which cause most of the damage.

The much thicker layer of Alecular bearing material (.015" vs. .0008") allows the bearing to conform to problems such as metal to metal contact when there is mis-alignment present or the connecting rods stretch. Greater conformability means fewer bearing failures.

The Alecular material’s melting/fatigue point is over 1100⁰ F, almost three times that of the thin babbitt overlay in a tri-metal bearing (400^OF). This means added protection against localized overheating due to mis-alignment, detonation, overloading, loss of coolant, etc.

Alecular bearings successfully withstand the stresses of blown, nitro-methane burning Top Fuel dragsters generating 5,000 hp at 8,000 rpm and in 700 hp circle track engines running for extended periods of time. The same metallurgical alloy is used in King’s street bearings that is used in King’s High Performance bearings, so the regular bearing user gets the advantage of the alloy developed and used in race engines.

Bearing -to- journal clearances on main and connecting rod bearings can be affected by several variables, all of which the engine builder must try to control. King has removed concerns about inconsistent shell to shell bearing wall thickness by the use of statistical control methods to keep wall thickness to very limited variation.

Other manufacturers produce bearings whose wall thickness at the crown can vary by up to + .00025". King bearings are produced using "Bull's Eye" specs which set a higher standard of controlling the wall thickness, permitting no more than + .00010" variation of the desired thickness.

The benefits of tight control of wall thickness tolerance are:

1. Improved consistency of bearing to journal clearance. No more trying different bearings within a set to get the "right" fit.
2. Superior eccentricity and crush relief values for a better oil "wedge" and less journal wear.
3. Less taper across the bearing face, meaning superior wall stability, a more parallel wall and better oil film development.
4. Crankshaft grinder does not need to grind cranks "fat" or "thin" to compensate for bearing variations.

 

All bearing companies solve crankshaft journal wear by supplying oversized bearings. However, King went two steps further with the development of Max Flange and Pro Flange. Max Flange reduces endplay by supplying the flange on the high side of the tolerance to compensate for crankshaft thrust surface wear; this process is used on all King bearings. Pro Flange are bearing sets supplied with oversized flanges allowing the thrust surface to be ground to .010", .020", or .030" undersize.