ARP 8740 Chrome Moly Hardened Washers - A Series Main Cap Bolts
ARP 8740 Chrome Moly hardened steel washers for the A-series main cap bolts. We use these on everything from our Standard Road through to Road Sports packages. This eliminates the need for centre main straps many believe is essential for up-rated A-series engines.
The problem with off the shelf centre main straps is that many available are poorly machined themselves which can have a negative affect on clamping force. The Centre Main strap first came about in the 1960s when it was believed that the only way to high performance was high rpm. Sustained high rpm caused the main cap bolt heads to chew in to the main cap flats, effectively reducing the torque clamping load. This then leads to the Caps loosening and jumping around, Eventually breaking. These steel washers prevent that from happening.