The fourth episode of this year’s Horsepower Wars just dropped, and we finally get to the part we all want to see: LME building a 5.3-liter Gen V LT that can handle up to 1,500 horsepower with boost. Last week’s episode covered the Coyote build and, by contrast, the LT doesn’t need any special tricks to compete in LS vs. Coyote 3.

For LS vs. Coyote 3, we step into the next gen with a 5.3-liter Gen V L83 engine, a configuration Chevrolet puts in its work trucks and calls the EcoTec3 5.3L V8. LME is building this LT to go head-to-head against a 5.0-liter Ford Coyote built by FFRE in our unique drag-and-drive contest.

A brand new aftermarket block? Nope, not for this build. Just a used L83 block.

The Chevy Counterpunch

We found out last week that the Coyote started with an all-new Ford performance Gen 3 Coyote block that FFRE immediately dug out of the crate and machined to take aftermarket sleeves. They stated that the 5.0 needs a thicker sleeve once the build is aiming for around 1,300 horsepower or more.

LME, on the other hand, took an L83 5.3-liter out of the junkyard as the basis of their build. The block did not use sleeves, nor any other major modifications. Even the stock nodular iron main caps were retained with upgraded ARP 8740 main studs.

Our whole goal was to turn as much RPM as possible. With similar displacement and turbo size, the way to level the playing field was airflow and RPM. —Bryan Neelen, LME

The block did require a 0.020 overbore to clean up, which is allowed by the rules. Fitted in the bores are a set of pistons that are one of the few parts that were specially ordered for this build: custom Diamond pistons. Forged from 2618 aluminum, these measure 3.800 inches in diameter and are actually a dome design with a heat-resistant coating instead of the usual dish for boosted applications. LME is aiming for max power on race gas with around 12.5:1 compression.

The crankshaft LME chose is Manley’s Pro Series 4340 forged steel crankshaft with the stock 3.622-inch stroke. It is a non-twist forging that is shot peened and magnafluxed for any cracks before it leaves the factory. 6.125-inch Manley forged 4340 steel Pro Series I-beam rods with ARP2000 rod bolts hold the pistons to the crank and will handle LME’s goals of over 175 horsepower per cylinder.

The parts fitted into this short block are top of the line, but not unobtainium. These parts were sourced off the shelf from Summit Racing, which can also handle the custom piston order. This is what makes the late model GM V8 platforms so appealing—no special parts or machining required to hit high horsepower goals.

A single row IWIS C5R timing chain is adequate for this screamer.

Breathing Room

Per the rules, both engines have to utilize stock cylinder head castings, but porting is allowed. LME knows the 4-valve Coyote can rev and breathe, so this is where the magic lies to compete. LME took the stock used L83 cylinder heads and treated them to one of the CNC porting programs. While one-off porting is allowed, Neelen was more than confident of their proven port work. The only change made was a fresh valve job to fit Manley titanium 2.060-inch intake valves and 1.580-inch exhaust valves.

9,000 RPM Stability

Late Model Engines collaborated with COMP Cams to develop a custom-ground camshaft paired with a fully matched valvetrain for LS vs. Coyote 3. The cam specs out at 254 degrees of intake duration and 268 degrees of exhaust with a 119-degree lobe separation and .648-inch lift. LME selected COMP’s Evolution hydraulic roller lifters to ride the camshaft. You read that right, per the rules, we are sticking to a hydraulic valvetrain for both engines.

Horsepower is just airflow and RPM. If we can match the Coyote in those areas, we can be competitive.—Bryan Neelen, LME

These lifters use tie bars, eliminating the need for the stock plastic lifter trays that prevent factory rollers from spinning in the bores. To keep things stable at the lofty 9,000 rpm target, LME outfitted the Manley titanium intake and exhaust valves with COMP’s conical springs. They’re lighter than dual springs, which reduces mass at the rocker tip and is critical for stability at high RPM.

Chevy Still Holds the Edge

Before the turbo system goes on, LME threw the 5.3 on the dyno for a brief break-in and validation. On VP C16 race fuel and naturally aspirated, the little LT made 608 horsepower at 8,500 rpm. Once the 76mm HPT turbo goes on, things will get serious.

What the Coyote lacks in displacement, it makes up for in head flow and RPM. But with LME at the helm, the Gen V 5.3-liter LT can rev and breathe like its DOHC competitor, and it didn’t need a bunch of fancy parts or machine work to do it, just the team at LME knowing what they’re doing. With both engines now ready for the dyno, we are one step closer to seeing who wins LS vs. Coyote 3!