Over the course of three days, December 7-9, 2023, The annual PRI Show in Indianapolis, Indiana played host to some of the latest and greatest the Performance Racing Industry had to offer. It also was the site where our 1,200-horsepower Gen-III HEMI giveaway engine came to life. Starting Thursday, Late Model Engines’ Vinnie Monighetti expertly assembled the Mopar live on the show floor, right in the Power Automedia booth.
As in previous years, we are teaming up with Summit Racing to build this giveaway engine to award to a lucky winner, entered at EngineLabsGiveaway.com (So make sure to get entered now. Here’s an additional entry — WEDGE — pay attention, because there’s another code for another additional giveaway engine entry later in this article.) However, unlike previous years, this engine is A) a Gen-III HEMI and B) uses a positive-displacement supercharger to reach its 1,200-horsepower goal.
Before the show, the team at LME machined the block, made sure the big end of the connecting rods were round and on-size, packed up the parts, and put them on the truck for Indy. From there, we loaded them into our booth the day before the show, and when the show opened on Thursday, Vinnie got to work turning the pile of boxes into an impressive powerplant.
Building The Base
If we’ve said it once, we’ve said it a thousand times; the most important part of an engine build is the block. It is the foundation of every other part, and if it isn’t right, or up to the task, the engine will only be worth its weight in scrap iron. For this project, we started with a factory-new BGE 6.4-liter iron truck block, provided by Callies Performance Products. The BGE (short for Big Gas Engine) block is the most desirable of the OEM HEMI blocks, thanks to its high-nickel iron alloy and revised coolant passage design with additional material thicknesses at key points, internally. This creates better bore stability in high-horsepower applications. LME opened the factory 4.090-inch bore up to 4.095 inches.
LME then fitted a set of Energy Manufacturing’s billet steel main caps along with an ARP Main Stud Kit to the block, replacing the factory cast steel pieces. Then, a quick align-hone made sure the main journals of the new caps were all perfectly sized and aligned. While these blocks have proven to be stout performers in stock form, there’s nothing like a little extra insurance when you’re looking to make power well into the four-digit zone.
The factory oil squirters were blocked off, not so much for any reasons of performance (we know how hot of a topic oil squirters can be), but simply for the needed clearance with the 4.050-inch-stroke crankshaft. More on that later. To house the crankshaft, we decided to go with a set of King Engine Bearings’ pMax Kote main bearings. Besides being able to withstand the cylinder pressures we are looking to make, the coating offers extra protection in case of temporary oil-pressure hiccups, along with a little extra embeddability in order to protect the crankshaft’s journals.
Using A Beefy Rotating Assembly
Sitting in the King bearings, we dropped in one of Callies’ Compstar Gen-III Hemi crankshafts. Made out of forged 4340 steel in several variations, we opted for the fully counterweighted version with eight counterweights. Those counterweights are profiled right out of the box for a 6.125-inch-long connecting rod. As mentioned previously, we chose the 4.050-inch stroke length, which when coupled with the 4.095-inch bore makes for the iconic 426 cubic-inch displacement.
Both the main and rod journals on our Compstar crankshaft have been drilled for both reduced weight and improved ventilation. While the crank uses the factory 2.559-inch main journal size, unlike the factory crankshaft, the Compstar used a Chevrolet rod-journal diameter of 2.100 inches. This made connecting rod selection easy, as a 2.100-inch journal, 6.200-inch-long rod might sound very familiar to you; it’s a Chevrolet connecting rod.
Because we’re going to be making some serious cylinder pressure, we needed a serious rod. So we went with Callies Ultra Enforcer connecting rod. Made from high-end 4330V aerospace steel, the buckle-resistant I-beam design is specifically designed for boosted applications. Advertised as good up to 2,000 horsepower, the rods come standard with L-19 alloy bolts, and only weigh in at 662 grams per rod.
Moving on to the piston, we opted for one of Diamond Pistons’ Hemi2K-series pistons. The “2K” series pistons started off life as a some of the most commonly ordered custom features, combined into a single part number that was then kept on the shelf in popular bore sizes. That has extended from the original LS2K line into Ford and Mopar applications. This piston is forged from 2618 aluminum with a 0.927-inch pin bore and a 1.5mm, 1.5mm, 3.0mm ring pack.
Included with the piston are a set of Trend thick-wall wrist pins made from H-13 tool steel. The quarter-inch-thick pin wall makes for an exceptionally strong wrist pin, without excessive weight. Also included with the Hemi2K pistons are a set of Total Seal piston rings, which we legitimately file-fit on the show floor. The 1.5mm top ring is a stainless steel piece, with a cast iron Napier second ring. The oil control ring also features a support rail, as the ring groove intersects the pin bore. Everything is held in place with standard round-wire locks.
Buttoning Up The Giveaway Engine Short Block
With the rotating assembly in place it was time to button up the rest of the short-block. For the oil pan, we opted for the same pan found on the late-model Challenger Drag Pak cars — the Milodon Hellcat pan. The steel pan features a louvered windage tray, crank scraper, and trap-door baffles to control oil movement under hard acceleration and deceleration. Milodon actually developed the pan to remedy the oil control issues on the early Drag Pak cars, and now sells it on its own.
To provide oil to the engine, Melling’s 10542HV pump was chosen. The High Volume pump is actually standard on the Hellcat engines, or is an upgrade to any other Gen-III HEMI that needs additional oil volume. Since we’re going to essentially be a higher-performance Hellcat engine, we opted for that extra oiling. Then, in front of the gerotor pump was mounted an ATI Performance Products Super Damper. Not just any Super Damper, but a 10-percent overdrive unit. Fun fact – Dustin Whipple stopped by while we were installing it, and ran some numbers, so we might be swapping to the standard-size 10-rib shell before we dyno-test the engine. Also, here’s another free giveaway engine entry code for you: HEMISPHERICAL.
The front and rear of the giveaway engine are sealed up with OEM front and rear covers. Sometimes, stock parts genuinely are good enough. And with that, we come to the end of Part One of the engine build. Make sure to stay tuned for Part Two, where we bolt on the cylinder heads, valvetrain, and the piece de resistance, the Gen-6 3.8-liter Whipple supercharger.
The 2023 EngineLabs’ Engine Giveaway is presented by Summit Racing and made possible thanks to partnerships with Late Model Engines, AMSOIL, Automotive Racing Products, ATI Performance Products, BendPak, BOOSTane, Brisk Racing, Callies Performance Products, Cam Motion, Cometic Gaskets, Diamond Pistons, Fuel Injector Clinic, Jesel Valvetrain, Johnson Lifters, King Engine Bearings, Kooks Custom Headers, Melling, Milodon, Performance Distributors, Powermaster Performance, Thitek, Total Seal, and Whipple Superchargers.