Unlike many modern engine designs, the Gen-III HEMI block eschews the four vertical main fasteners and instead only uses two, albeit still with two cross bolts in the block skirt. While a block like the BGE (Big Gas Engine) is pretty darned robust, the four-bolt main cap arrangement allows for improvement.
In order to absolutely bulletproof a Gen-III HEMI iron block, Livernois Motorsports developed a billet-steel main cap upgrade. By slightly redesigning the shape of the cap to better withstand extreme loads and then machining the caps out of solid 1044 steel plate, Livernois has increased the capability of the OEM blocks significantly.
1044 steel is a medium-carbon steel that is often used in heavy-duty mechanical components and is significantly stronger than the OEM powdered-iron main caps. Improved geometry also helps strengthen the Livernois billet main caps, but that geometry was carefully designed to not cause any interference within the oil pan or with OEM and aftermarket windage trays.
The Livernois billet main cap kit comes with billet replacements for all five main caps on a Gen-III HEMI, and will fit the entire lineup of OEM blocks: 5.7-, 6.1-, 6.2-, and 6.4-liter versions. Main cap material isn’t the only upgrade Livernois makes to the bottom end of Gen-III HEMI engines. They use ARP’s main stud kit to secure the billet main caps to the block.
Made from 8740 chromoly steel, ARP’s 12mm main studs and 8mm side bolts have a 190,000 psi tensile strength — quite a bit more than the OEM bolts. Besides the material, the design of the ARP studs over the OEM bolts increases clamping strength, with their 100 lb-ft torque spec. The combination of studs and billet main caps adds significant strength and durability over even the BGE block’s OEM arrangement.
You might also like
Maximizing Factory Hellcat Cylinder Head Porting With Livernois Motorsports
When it comes to factory cylinder head porting, Livernois has tons of experience making good factoy heads flow even better.
