King Engine Bearings Rod Bearings 0.25 Over Sized 52mm Journal Size WRX / STI

Unique Geometric Design:
In racing main bearings, the grooves shape and size perform a vital role. The groove should be wide enough to allow sufficient oil flow, but narrow enough to maximize the working surface.  In today's race engines, contrary to popular belief, there is significant load on the upper main bearing shells. The extra load is a product of the inertia forces generated by high RPM. The extra force demands higher load capacity.
In response, King Racing TechLab developed U-Groove a unique 90° oil groove shape. U-Groove increases bearing load capacity by expanding the surface area, while keeping oil flow capacity intact.
-Better load distribution across the bearing surface
-A more stable hydrodynamic lubrication regime
-Greater bearing durability at high RPM

Bull's Eye Tolerance:
Typical race bearings are manufactured to meet the industrys traditional +/- 0.00025  wall thickness tolerance. But race engine builders often prefer narrow, more specific oil clearances with far more tolerance control.
To achieve the right clearance, they compensate for bearing thickness inconsistencies by grinding cranks fat or thin, adjusting the housing bore, or purchasing multiple sets to fish for shells. The process is time consuming, costly and tedious.
King listened to its engine building customers and responded with Bull Eye Tolerance
Bulls Eye Tolerance is a production technology developed by King. It combines highly accurate machining, overplating, and computerized wall thickness monitoring that adjusts the process on-the-spot.
Bulls Eye Tolerance outperforms the industrys wall thickness tolerance, ensuring the least thickness variation shell-to-shell. The outcome: A new standard in bearing thickness consistency.
-No more multiple set purchases or fishing for bearings to reach right clearance
-No need to grind cranks fat or thin
-No need to adjust housing diameter

pMax Black tri-metal structure:
The intermediate layer of a typical race bearing contains 2-3% tin, with hardness values of 90-95 HV. Within the pMax Black intermediate layer, we increased the tin content to 4.5%, making it 22% harder at 115 HV, with a load carrying capacity of 17000 psi. pMax-Black Overlay.  The overlay of a typical high performance bearing features a leaded alloy that contains 2-3% copper content. The bearing reaches a hardness level of 11-11.5 HV, and a maximum fatigue resistance at 8000-8500 psi.  King pMax Black overlay is significantly stronger than conventional overlays due to its 5% copper content and an innovative nano-scaled hardening process.  King Racing pMax Black overlay is strengthened by a proprietary nano-scaled hardening process that modifies the molecular structure and creates a black fatigue-resistant shield. The outcome is a significant 24% increase in hardness and load capacity, reaching 18.1HV and maximum fatigue resistance of 10,200 psi.  SecureBond Maximum tri-metal structural integrity.  High loads and high RPM create critical stress levels that filter through the multi-layer construction of a tri-metal race bearing. SecureBond is a micro-etch surface preparation process. It strengthens the tri-metal structural integrity, reduces likelihood of catastrophic failure due to delamination of one layer from the other under extreme load conditions or metal-to-metal contact.

Applications:
2002-2007 WRX
2004-2007 STI
2008-2014 WRX
2008-2014 STI
2015-2021 STI