In the first installment of the fourth season of Horsepower Wars, presented by Summit Racing, we touched on the LS vs. Coyote 3 series that will kick off the season. In this second installment, we are going to dive deep into the rules, talk about the core engines being used, and then talk about the build plan and parts a little bit. This running of LS vs. Coyote will have some notable differences from years past, so you’ll want to pay close attention.

LS vs. Coyote 3 Rules

In the past runnings of the competition, we made the engines naturally aspirated, and then in the second competition, we built the engines with a centrifugal supercharger. So, for this competition, we’re going to use a turbocharger as the spec power adder. More on that in a bit.

When naturally aspirated, we imposed a $9,999 budget for each engine. With the supercharged engines, they had a $15,000 parts budget, not including the ProChargers. Each time previously, it seemed like the artificial budget cap unfairly hurt the Coyote. So, for this running, we’re doing away with a fixed budget cap. We’ll still track and publish the final costs, though.

The biggest feature of this season’s rules is the displacement cap. Last time, teams were allowed to displace whatever they could squeeze into the blocks. This season, we’re really tightening that up. It’s no secret that the architecture of the Coyote makes it difficult — and incredibly expensive — to increase displacement. That has led to the bowtie engine always having a significant displacement advantage.

The original LS vs. Coyote featured stock-displacement engines with a $9,999 all-in budget. It pitted an LS3 against a Gen-1 Coyote.

In order to try and keep the playing field level, we decided to take the most common Gen V engine, which is the closest in displacement, and use that to base the rules around. That is the 5.3-liter Gen V L83 engine. Like the 5.0-liter Coyote, the L83 is found in current production pickup truck applications, making this an apples-to-apples comparison. For the Coyote, sure, we could have gone with a 5.2-liter variant to drop the 0.3-liter difference down to 0.1 liter, but then we would have a high-performance Voodoo or Predator going against a simple truck engine. 0.3 liter is good enough for the girls we go out with.

In order to keep the displacement close, we are tightly controlling short-block modifications. We are requiring both teams to maintain a factory engine block this year. Any machine work — like sleeving — needs to be approved ahead of time and fall within the spirit of the rules (so none of those sleeves with integrated deck reinforcements). We are only allowing the stock stroke to be used, and a maximum of only twenty-thousandths of an inch (.020) of overbore. That makes the maximum possible displacement difference between the two engines 26 cubes, and potentially as little as 11 cubic inches.

Since we aren’t imposing a strict budget on this build, we are imposing a restriction on the crankshafts. Regardless of whether an OE or aftermarket crankshaft, factory-size main and rod journal diameters must be maintained, so no tricky business with the bearing sizes.

Round two of the competition removed any displacement limits, upped the budget to $15,000, and added forced induction via F-1 ProChargers.

For the cylinder heads, we’re allowing standard porting of cast heads only. That means no billet heads or crazy welding or epoxying of the ports is allowed. Additionally, we’re requiring a functional hydraulic valvetrain to be maintained. That’s how both engines came from the factory, and that’s how they’re going to stay in the competition.

Now, the big one: the turbo. Both teams are required to run a 76mm F3-series turbocharger from HPT Turbo. Both teams must have the same 76mm billet compressor wheel and the same compressor housing, along with the same 80mm turbine wheel. But, there are several different HPT turbine housing options the builders can choose from.

The teams can run either a standard 0.96 or 1.24 A/R turbine housing in either V-band or T4 flange designs, or they can use HPT’s 1.28 A/R divided turbine housing. The turbine housings used in the dyno competition can be changed once the engines are put into the trucks. We’ll be diving much deeper into the teams’ turbo selection and the turbo specs in a later episode.

For charge cooling in round two, we used a big racecar air-to-water intercooler. The coolers this year are much more streamlined, while still having tons of capacity.

In order to keep the intake charge as cool as possible, each team will be using a direct-fit Tick Performance intake manifold intercooler core on both combinations. This should keep IATs in check equally for both engines without either team getting an advantage.

Both combinations will only be allowed to run port fuel injection controlled with identical Holley Dominator EFI systems. Each team will be limited to E85 fuel with a maximum of eight fuel injectors of any size allowed.

For any part used in the competition, in any part of the engine, both teams must use off-the-shelf components that are commonly available to the public through major retail outlets, like Summit Racing. The only exception to this is the camshaft and pistons: both of those can be custom-built pieces.

Once the engines are both assembled, they will be shipped to Westech Performance Group in Southern California, where they will be allowed one full day on the SuperFlow 902 engine dyno, under the supervision of the Horsepower Wars staff. The goal there is simple: the highest peak horsepower number wins. No averages, no horsepower-per-cube numbers. Just one magic horsepower number. Nice, clean, and simple.

The base 5.3-liter Gen V L83 engine. From the factory it was rated at up to 380 horsepower.

The Core Gen V Engine

The team from Late Model Engines out of Houston, Texas, is building the Chevrolet entry. From the factory, the L83 is an all-aluminum Gen V 5.3-liter engine, currently found in truck applications, and isn’t often used as the base for performance applications. However, that isn’t stopping LME from treating it like any other performance Gen V build.

The Gen V L83 cylinder heads are quite an improvement over the previous generations of cylinder heads, though. Out of the box, they come with bigger intake and exhaust ports — 248cc and 102cc, respectively — and smaller combustion chambers than its Gen III and IV counterparts.

While the smaller combustion chamber pumps up factory compression, it also makes it tough to shove a huge valve into. However, the valve angles have been revised in the L83 heads, rolling the valve over, and allowing it to open away from the cylinder wall, meaning that, in theory, a bigger valve can be used than in previous small-bore applications. The L83 cylinder head is no slouch of a factory head — the heads flow better than any other factory GM small-bore offering out of the box — and could lead to some interesting results, depending on what LME does with it.

Here is the OEM Gen-3 Coyote. From the factory, the Gen-3 truck engines were rated at 395 horsepower. However, since we’re disallowing direct injection, our engine will have Gen-2 cylinder heads on it.

The Core Gen-3 Coyote

Since we wanted to use one of the modern iterations of the Coyote, but direct injection is explicitly disallowed, the core Coyote engine is a Gen-3 bottom-end with Gen-2 cylinder heads. This Coyote configuration is a proven performer with our Coyote builders, Fast Forward Race Engines from New Port Richey, Florida, selling the exact combination day in and day out.

The Gen-3 block has been shown to be an amazing base to build on, coming in both Mustangs and F-150s. The dual overhead cam Gen-2 cylinder head flows a ton of air, even in stock form, and it’s been proven to absolutely love boost and RPM. So really, with such similar bore and stroke, the question becomes, is this a battle of cylinder heads?

Some Killer Parts

While the L83 will use an aftermarket crank, both engines will be running factory-dimension crankshafts, with upgraded rods and pistons. They will need to balance weight versus strength when picking the rods, and manage all of the variables that come into play with a custom piston. Do they free up power with thin ring packs, with a potential reduction in longevity? Keep in mind, these engines will have to handle 100 to 300 miles of street driving before making three back-to-back passes at the dragstrip.

What about the crown design? Do the builders run a big dome to up static compression at the risk of slowing down flame propagation? What’s the ideal compression ratio for big boost? They are limited to E85 as fuel, so that will need to be taken into account, too.

Both teams will be running custom cams. Obviously, each builder will be working closely with the engineers at COMP Cams, but what voodoo will the teams call on in the valvetrain? There are a lot of ways to make big power with camshafts, but there are orders of magnitude more ways to NOT make power as well. Getting the valve events right will be incredibly important when trying to max out a power adder.

There are very few “custom” parts allowed in this round of competition, but the camshafts and pistons are wide open.

This competition is far more than just slapping some parts together and cranking up the boost. With such a tight restriction on the turbocharger, it’s really going to come down to the small details in the engine combinations for one side to have an advantage over the other.

Luckily for you, the next two episodes are dedicated solely to the engine builds. First, we’ll head down to Florida to spend a couple of days with Fast Forward Race Engines as they build the Coyote. Then, we’ll hop a flight to Texas to visit Late Model Engines to follow the L83’s build.

Make sure to stay tuned to EngineLabs’ YouTube channel for the next episodes of LS vs. Coyote 3 and new content every Thursday. If you aren’t already, subscribe to the channel so that you don’t miss any of the third running of the LS vs. Coyote competition.

Horsepower Wars would like to thanks its sponsors for making this possible including Summit Racing, Holley (Holley EFI, Simpson, etc), Manley Performance, Diamond Racing Pistons, COMP Cams, Moroso Performance Products, Automotive Racing Products (ARP), Cometic Gaskets, AMSOIL, Vibrant Performance, HPT Turbochargers, ICT Billet, ATI Performance, Meziere Enterprises, AFCO Racing, Optima Batteries, Old World Industries/Peak, Strange Engineering, SPAL, Auto Metal Direct, and Wiles Driveshaft.