Livernois Motorsports Dives Into The Gen-III HEMI Market With A 401-Cube Short-Block

When you hear the name “Livernois Motorsports,” you’d be forgiven for immediately thinking “Late Model Ford.” After all, that is what they built their name on. But the team at Livernois is broadening their horizons. While it can be argued that an engine is just an air pump, and what works in one will work well in another, Livernois is going beyond just building different engine families, expanding its parts manufacturing to other platforms as well. In order to highlight their broadening of the mind, as it were, the team decided to build a 401-Cube Gen-III HEMI to show off their parts and services.

A 401-Cube Mopar Foundation

In the Gen-III HEMI world, the Mopar BGE (Big Gas Engine) block is a common choice as a base, and with good reason. Designed for all of FCA’s 6.4-liter HEMI applications, as well as some of the 6.2-liter Hellcats, the BGE block is a production iron block that has an architecture designed to hold up under serious loads. The community regularly loads the BGE block deep into the four-digit horsepower range, meaning the BGE block will be more than enough for this particular build.

Of course, Livernois isn’t going to just use an off-the-shelf block without tweaking things some. They chucked the BGE block into their machines and opened up the bore to a stout 4.100 inches. While it was in the machine shop, they also machined the block for a set of the new six-bolt billet-steel main caps.

The five-piece billet main cap kit has the OEM four-bolt (two vertical main bolts, two cross-bolts) design, but is machined from billet 1044 steel. The shape of the caps closely mimics the factory cast pieces, so clearance issues are non-existent, while strength and durability are increased significantly.

It was decided to drop a 3.800-inch-stroke Callies Compstar crankshaft into the mains. Besides being forged from 4340 steel for much improved strength, out of the box, the Compstar’s counterweights are clearanced for 6.125-inch connecting rods. The main journals are the standard 2.559-inch HEMI diameter, but gun-drilled for reduced weight. The rod journals are slightly reduced to 2.100 inches from the HEMI’s 2.126-inch diameter, which makes for a wide selection of connecting rods.

For the connecting rods, Livernois chose to use a set of CP-Carrillo Pro-H straight-H-beam connecting rods. The CP-Carrillo rods are made from 4330m steel and have a straight H-beam design that balances weight with strength. The rods come with 3/8-inch bolts standard, and Livernois opted for Carrillo’s CARR rod bolt upgrade. As has become common in the Gen-III HEMI world, the 2.100 main and .927 bushed small end mean the rod carries an LS part number.

Hanging off the rods is a set of heavy-duty CP Bullet pistons. Made from 2618 forgings for maximum strength under boost, the 8cc-dished crowns are coated with a gold ceramic thermal barrier coating, along with an anti-friction skirt coating. Holding the pistons to the rods are .927-inch diameter, 2.25-inch long, .200-inch-wall steel wrist pins for strength under serious cylinder pressure. A steel ring package was chosen for durability under boost. The combination should spec out in the 9.7:1 range for compression ratio, when all is said and done.

Tried-and-true Clevite H-series bearings were used for both the rods and mains, while the factory Mopar oil pump was retained to provide lifeblood throughout the engine, along with the factory Mopar oil pan. Similarly, the OEM Mopar timing set will be reused, and variable valve timing will be retained. An ATI Super Damper is used as part of the Livernois S1025 package that was previously installed on the stock engine.

Besides machining the block for their billet-steel main caps, Livernois precision-balanced the rotating assembly after fitting a Mopar 58-tooth reluctor wheel to the Callies crankshaft. The mains were secured with an ARP main stud kit. Made from 8740 chormoly steel, the ARP main stud upgrade, combined with the billet main caps, will provide a rock-solid foundation for the rest of the build.

With a laundry list of incredible components and Livernois’ proven assembly methods derived through decades of experience, the team is coming out of the gate hard to showcase what a Livernois-built Hellcat engine is capable of.

Livernois Motorsports 401 Cubic-Inch Gen-III HEMI Short-Block Spec Sheet:

• Engine Family: Chrysler Gen-III HEMI
• Engine Block: Chrysler 6.4-liter BGE (Big Gas Engine) iron block
• Block Modification: Cylinders bored and billet main caps fitted
• Bore and Stroke: 4.100 inches by 3.800 inches
• Total Displacement: 401 cubic inches (6.577 liters)
• Crankshaft: Callies Compstar forged 4340 steel; 3.800-inch stroke, 2.100-inch rod journals, OE main Journals; 58-tooth reluctor
• Main Bearings: Clevite H-series
• Main Fasteners: ARP 8740 main studs
• Connecting Rods: Carrillo Pro-H 6.125-inch forged 4330m steel
• Rod Bearings: Clevite H-series
• Rod Bolts: Carrillo 3/8-inch CARR upgraded bolts
• Pistons: CP forged 2618 4.100-inch; -8.0cc dish
• Piston Coatings: Ceramic thermal piston crown coating; Anti-friction piston skirt coating
• Wrist Pins: .927-inch diameter, 2.25-inch long, .200-inch wall-thickness, tool steel
• Oil Pump: Factory Mopar Hellcat
• Oil Pan: Factory Mopar
• Timing Set: Factory Mopar variable valve timing
• Harmonic Damper: ATI Super Damper