Ask five airboaters what the best engine is and you’ll get five answers and at least one argument. The truth is less dramatic: the right engine depends on your hull, your load, and what you actually do with the boat. A frogger running skinny trails has different needs than a survey crew hauling gear across a marsh five days a week.
At Patriot, we build boats around four engines we trust. All four are EPA-certified, built on GM architecture, and set up specifically for airboat duty. We also install them as repowers on any make of airboat, so if your current engine is tired, everything below applies whether you’re building new or breathing new life into a boat you already love.
Here’s how the four compare, and who each one is really for.
The Lineup at a Glance
| Engine | Builder | Displacement | Horsepower | Fuel | Best For |
|---|---|---|---|---|---|
| LT4 Marine SportPac | Marine Power | 6.2L DI (supercharged) | 665 HP (Patriot tune) | Gas | Maximum power, heavy loads, big hulls |
| Levitator LSX MS 70 | Pleasure Craft (PCM) | 7.4L | 525 HP | Gas | Naturally aspirated torque, simplicity, long days |
| Duramax L5P | Marine Power | 6.6L turbo-diesel | 450 HP | Diesel | Fleets, agencies, fuel economy, engine life |
| AirPac | Marine Power | 6.2L | 525 HP | Gas | Airboat-specific tuning, throttle response, all-around use |
LT4 Marine 6.2L DI SportPac: 665 HP, by Marine Power
If you want the most power on this list, this is it. The LT4 is a supercharged, direct-injected 6.2L built on the same GM architecture found in some of the strongest production V8s ever made. Marine Power marinizes it, and we tune it for airboat duty at 665 horsepower.
What that power means in practice: big hulls loaded with people or gear get on plane and stay there. Dry ground transitions that make smaller engines groan barely register. If you’re running a 20-foot boat with a full deck of equipment, or you just refuse to be passed, the LT4 is the answer.
The direct injection matters too. It burns fuel more efficiently than older port-injected engines, so you’re getting the power without the fuel bill you’d expect from 665 horses.
Choose the LT4 if: you run heavy, run big, or run hard. It’s the flagship for a reason.
Skip it if: you have a lighter hull that doesn’t need the power, or you want the simplest possible setup. A supercharged direct-injection engine is more machine than some boats call for.
Levitator LSX MS 70, 7.4L: 525 HP, by Pleasure Craft
The Levitator name has been around the airboat world for a long time, and there’s a reason old-timers on the forums still bring it up when someone asks about durability. The MS 70 is 7.4 liters of naturally aspirated displacement. There’s no supercharger and no turbo, just cubic inches doing what cubic inches do.
That simplicity is the point. Naturally aspirated engines have fewer things to maintain and fewer things to fail, and big displacement means the torque shows up low in the rev range, right where an airboat spends most of its life. Pulling a loaded boat through thick grass or over a levee is torque work, and 7.4 liters makes torque without breaking a sweat.
Choose the Levitator if: you value proven, simple, and strong. It’s the engine for people who put hundreds of hours a year on a boat and want every one of them to be uneventful.
Skip it if: you need maximum horsepower per pound. The LT4 makes 140 more horses from a smaller package.
Duramax L5P Diesel, 6.6L: 450 HP, by Marine Power
Here’s something most airboaters don’t know: this is effectively the only marinized diesel available for airboats. Marine Power starts with the current-production GM Duramax L5P, the same engine platform GM puts in its heavy-duty trucks, and builds it into a clean, low-vibration package rated at 450 HP for airboat use.
Why go diesel on an airboat? A few real reasons:
Fuel economy and range. Diesel goes further per gallon, which matters when you’re deep in a marsh with no fuel dock in sight.
Engine life. Diesels are built to run steady under load for thousands of hours. For commercial operators, survey crews, and agencies that log serious hours, that’s the difference between an engine and an investment.
Fleet logistics. If your organization already runs diesel trucks, generators, and equipment, a diesel airboat means one fuel supply for everything. Procurement departments notice this.
The 450 HP number undersells it a little, because diesel torque behaves differently than gas horsepower. The L5P pulls hard from low RPM and doesn’t fade under sustained load.
Choose the Duramax if: you’re an agency, a commercial operator, or anyone who measures engine use in hundreds of hours per year and wants fuel commonality with the rest of a fleet.
Skip it if: you’re a recreational boater who wants maximum sound and speed on weekends. Gas is lighter, cheaper up front, and more fun per dollar for that use case.
AirPac 6.2L: 525 HP, by Marine Power
The AirPac is the engine Marine Power built specifically for airboats, and it shows. Airboats put a unique kind of stress on an engine: fast throttle changes, constant load shifts as the boat moves between water, grass, and dry ground, and long stretches at high output. The AirPac’s tuning is designed around exactly that duty cycle.
Depending on configuration, AirPac packages include direct-injection Gen V options controlled by the MEFI 7 ECM, and supercharged variants for those who want more. At 525 HP in our standard tune, it sits in the sweet spot for most mid-size hulls: enough power for real work, responsive enough to feel sharp, and efficient enough to keep fuel stops reasonable.
Choose the AirPac if: you want an engine designed for airboats from the start, and 525 HP covers your needs. For most owners, it does.
Skip it if: your use case pushes you clearly toward the LT4’s power or the Duramax’s diesel economics.
Repowering? All Four Engines Drop Into Any Make of Airboat
This part matters if you already own a boat. You don’t need a Patriot hull to run any of these engines. We repower all makes and models: Diamondback, American, Panther, GTO, custom builds, whatever’s in your shed.
A repower makes sense in a few situations:
Your engine is tired but your hull isn’t. Airboat hulls outlast engines. If your boat still fits your life but the engine smokes, struggles to start, or eats a repair bill every season, new power costs a fraction of a new boat.
You bought used and inherited someone else’s engine choices. Plenty of good used hulls are out there wearing the wrong engine. A repower fixes that.
You want to move from an aircraft engine to automotive power. Parts for automotive-based engines come from any parts store instead of an aviation supplier, and modern marine V8s make more power than the Lycomings and Continentals they replace. It’s the most common conversion we’re asked about.
Your work changed. Started guiding? Hauling more gear? Running further? The engine that fit your old life might not fit the new one.
When you repower with Patriot, we handle the whole job: pulling the old engine, matching the new package to your hull and prop, the rigging, and the tuning. Every engine leaves dialed in for your specific boat, not just bolted in and handed back.
And if you’ve got a different engine in mind, one that isn’t on this page? If it’s rated for airboat use, ship it to us and we’ll install it. We’re not precious about it.
Common Questions
How much does it cost to repower an airboat? It depends on the engine package, what your current rigging looks like, and whether your gearbox and prop carry over. Rather than quote a vague range, call the shop at (409) 422-0006 and tell us what you’re running. We’ll give you a real number.
Gas or diesel for an airboat? Gas for most recreational and hunting use: lighter, cheaper up front, more power per dollar. Diesel for high-hour commercial and agency work where fuel economy, engine longevity, and fleet fuel commonality pay for the premium.
Can you install an engine I supply? Yes. If it’s rated for airboat use and it can be shipped to our shop in Vidor, Texas, we’ll set it up, install it, and tune it for your boat.
Do these engines meet emissions requirements? All four are EPA-certified. For agencies with procurement requirements around emissions compliance, that’s already handled.
How long does a repower take? Depends on the package and our current schedule. Call ahead and we’ll give you an honest timeline before you commit.
Ready to talk power? Call Patriot at (409) 422-0006 or contact us and tell us what you’re running and what you want it to do. We’ll help you pick the right engine and install it clean.
