WPC-Treated Rod Bearing Set - E46 M3, Z4M

Product Description

This is a set of upper and lower rod bearings with the WPC surface treatment for E46 M3, MZ3, and Z4M S54 engines.

We take a standard BMW bearing shell and give it the WPC treatment, a microscopic shot-peening of the bearing -

• Removes high spots and imperfections
• Improves fatigue resistance
• Increase the surface's oil retention abilities for more lubrication
• Safer than a coating and will not decrease clearances
• Preserves the factory bearing's metallurgy

Rod bearings are a typical wear item and critical on high revving engines like the S54. The WPC treatment will prolong bearing life and reduce friction, however, bearings are still a wear item. There is no official replacement interval from BMW, and the last design revision seems to last a long time, but we feel comfortable recommending a preventative replacement every 100,000 miles. Track your bearing wear with regular used oil analysis and plan on rod bearing replacement some time in your engine's future.

Bearings are sold by size. These are the standard 49.0mm inside diameter size. Replaces original BMW part numbers 11247835440 and 11247835439.

Note: connecting rod bolts cannot be re-used. They are stretch-to-yield and must be replaced.

Price is for the set of 12 bearings for the S54 I6.

Engine Oil Note: we strongly recommend a quality oil such as Red Line because of its higher zinc content and better protection values at operating temps. For a dedicated track/race car the Red Line Racing oil has the most zinc and shear strength (but lacks the detergents desirable in street oils). Correct oil operating temperature is 220°F - you should properly warm your engine before subjecting it to higher throttle angles and RPM. For more info on engine oil in general, check out our Oil Tech Page by clicking here.