ACL - BMW M20/M50/M52/M54 Main bearings

High performance engines demands that you use the best parts. So rely on ACL’s Race Series Products to perform to the exacting race standards you expect. They provide the dependability it takes to hold up under higher RPM conditions, or higher turbo boost The unique combination of design, metallurgy and engineering come together to deliver what drivers expect from high performance parts.
 

• High strength overlay plate with reduced thickness for improved fatigue properties
• Hardened steel backs on all rod bearings to improve the support of the bearing lining and assist with bearing retention in the housing.
• Increased crush for improved bearing retention
• Elimination of flash plating on the back of the bearings to improve heat transfer through the bearings and to maximize the grip between the bearings and its housing.
• Increased eccentricity to compensate for bore distortion at high rpm and to assist in the formation of hydrodynamic oil films.
• 3/4 grooved Main Bearings to optimize bearing load carrying surface area and oil flow to the conrod bearings.
• Tight consistent wall tolerances to help you maintain consistent clearances.
• Enlarged ID chamfers on bearing edges where required to accommodate large fillet radius on performance crankshafts.

This bearing comes in multiple sizes which will be explained below:
"H" = Standard Size
"H-.25" = .25mm Thicker than stock. Use this when your crank is cut .010"
"H-.50" = .50mm Thicker than stock. Use this when your crank is cut .020"
"H-.025" = .025mm Thicker than stock. Use this when you need .001" less oil clearance.
"HX" = .025mm Thinner than stock. Use this when you need .001" more oil clearance.

Fits: BMW M20, M50, M52, M54.