ACL Race Series Conrod Bearings AU BA BF FG Falcon XR6 4.0 +0.010"

Will also suit 250ci Crossflow, SOHC 4.0L & DOHC 4.0L

ACL RACE SERIES BEARINGS EB004/2016 Set Numbering ACL RACE Series bearing sets are identified by the ‘H’ after the set number e.g. 8B663H-Std. Most ACL RACE Series bearings are also produced in a ‘HX’ version  e.g.  8B663HX-Std. The ‘X’ signifies the set will give an extra  .001” (.025mm) oil clearance on a standard size shaft when compared to the H-STD set.  The wall size of these HX-STD bearings is .0005” (.013mm) thinner than the H-STD Bearings, in all other respects the HX set is identical to the H-STD set. There are selected con rod bearing sets that are manufactured with a dowel hole in the lower shell, to suit a dowel location in the con rod cap. These are designated with a ‘D’ in the set numbering e.g. 8B663HD-Std or 8B663HXD-Std  etc. Appearance Questions about the appearance of the RACE Series bearings are quite common, as this series of trimetal copper lead bearings have a very different appearance to regular aftermarket “ACL Duraglide” trimetal bearings, which have a light silver /grey appearance. The RACE Series performance bearings as manufactured have an appearance that is a dark tarnished colouration, which can vary from dark black/brown/blue colours. This colour comes from the electroplating which is the last manufacturing process. The electroplated overlay has copper as one part of its composition, which tarnishes to the dark colours described above. This tarnish colouration has negligible thickness, so once installed in the engine, the crankshaft journal contacting the bearing, will polish the bearing surface, removing the surface colour and leaving the bearings with a polished silver appearance. Performance bearings do not start out with the silver grey appearance of regular aftermarket bearings, as there is no final silvery tin flash applied to these bearings. Not applying a silvery tin flash to these high performance bearings is a specific design feature. A silvery tin flash for appearance and long term corrosion protection, as applied to the regular aftermarket bearings, can under high loading and heat, move, with the plate migrating and causing high spots on the back of the shells, and distorting the bearing. For this reason the ACL RACE Series performance bearings do not have a cosmetic silvery tin flash applied, so there is no risk of any overlay plate movement on the backs of the shells, giving better bearing to housing contact and better bearing performance and function