WPC TREATED ACL BEARING SET FOR BMW S65 ENGINES
These Mporium customized, extra clearance rod bearings start out as ACL's Race Series lead/tin/copper 1580H and 1580HX bearing sets which we send out in large lots to be WPC surface treated for anti-wear. AFTER the bearings are treated we then measure each shell's thickness and sort them into lots to be matched together into perfectly mixed sets for the S65 engine. Each V8 set contains 8 top shells (H) and 8 lower shells (HX) which have been processed by Mporium for perfect S65 fitment. Each set targets .0024" nominal oil clearance for the S65/S85 engine. (NOTE: visible scuffs caused by measuring with the Mitutoyo indicator are normal and do not affect the bearing's function or longevity).
We have been offering these custom sets at our shop in Texas for many years and are now offering them as an economical upgrade option to off-the-shelf bearings for worldwide S65 owners. Our shop has installed these into hundreds of S65 and S85 engines over the years.
For those in the know, ACL's 1580H bearings provide clearances similar to the OE spec, yet their 1580HX "increased clearance" set may increase oil clearance too much. Therefore, it has been common practice to buy a set of both and "mix" them together and assume the clearance will be closer to the .0024" ideal clearance for a typical S65 crankshaft journal. The danger of blindly mixing ACL's pre-packaged lots of H ad HX shells is not knowing the dimensions of each bearing from set to set which can lead to wildly varying and undesirable oil clearances.
We take the guesswork out of the process by measuring and selecting each set for ideal clearances, and each set also has the added benefit of being WPC treated for anti-wear!
What is WPC treatment?
From WPC:
"The WPC process is unrivalled in treating engine parts and other surfaces that have contact points of friction. WPC is superior because it is not a coating; it is a permanent surface treatment that reduces friction while strengthening the part. It's unique micro-dimple formation pattern greatly reduces friction and is unmatched by conventional methods of surface treatment.
WPC has the capacity to treat carburized, nitrided and plated parts without noticeable dimensional changes, and, upon completion of treatment, no further modifications are required of the parts. The strength and durability improvement on the surface after the WPC treatment is unsurpassed by any current methods."
Each set is packaged in foam for protection in shipping. Each set is identified as "Upper" and "Lower" for correct installation.