Tri-metal big end bearings BMW M3 E36 Z3M S50B32

The ACL RACE and KING RACING tri-metal big end bearing sets for the S50B32 engine consist of 12 bearing shells.

Below you will find (click on the image) the tri-metal main bearings for the BMW S50B32 engine and the plastigage strips used to check the bearing to crankshaft running clearance:

Technical specification

• Crankshaft big end journal diameter (min/max): 48.975 / 48.991mm
• Con rod big end housing diameter (min/max): 53.000 / 53.015mm
• Max thickness: 1.993mm
• Size(s): standard or standard with HX clearance or +0.025 or +0.25mm
• Anti-friction coating: without
• References: 6B1497, 6B1497H-STD, 6B1497HX-STD, 6B1497H-.025, 6B1497H-.25

ACL Race Series tri-metal bearings are manufactured to exacting tolerances. CNC machining is carried out to within microns, followed by metrology inspection of the diameters, thickness and width of every ACL Race Series tri-metal bearing shell. ACL Race Series bearings therefore deliver a reliable and consistent fit in your performance engine. ACL Race Series tri-metal bearings are in fact made up of four layers:

• SAE1010 steel on the outside
• 0.3mm copper alloy
• 0.0001mm nickel
• copper alloy from 0.013 to 0.018mm

This material strategy, combined with the manufacturing processes, makes ACL Race Series tri-metal bearings more resistant to increases in power, torque and engine speed. The compressive strength of ACL Race Series tri-metal bearings brings reliability to your engine even with turbocharged or supercharged builds running high boost, or highly strung engines at high rotational speeds.

Technical specification

• Crankshaft big end journal diameter (min/max): 48.97 / 48.99mm
• Con rod big end housing diameter (min/max): 53.00 / 53.01mm
• Max thickness: 1.991mm
• Size(s): standard or standard with HX clearance or +0.026 or +0.25mm
• Anti-friction coating: without
• References: CR6853, CR6853XP, CR6853XP STDX, CR6853XP.026, CR6853XP0.25

Since 1960, KING RACING has designed and manufactured high performance, high quality bearings. Beyond its high performance production machinery, King Racing relies on simulation software to analyse the thermodynamics, dynamics and elasto-hydrodynamics of its bearings. KING RACING tri-metal bearings are produced in pMax Black, a tri-metal alloy 24% stronger than any existing tri-metal bearing.

KING RACING bearings are made up of 3 to 4 layers (depending on the application):

Outer: steel Intermediate: lead bronze Inner: overlay with a high copper content Anti-friction coating containing lubricant and ceramic additives