483 HP MV8 7.4L with One Drive (on Formula 370 SS)
EmailSend to a Friend

Ilmor 483 HP MV8 7.4L with One Drive (on Formula 370 SS) Main Video

Evinrude Banner

Text Size: AAA
Ilmor 483 HP MV8 7.4L with One Drive (on Formula 370 SS) Ilmor 483 HP MV8 7.4L with One Drive (on Formula 370 SS)
The Ilmor 483-hp MV8 7.4L is matched to a One Drive® sterndrive and the setup fills a gap between the 430-hp sterndrive offering from Mercury and Volvo Penta, and the 520-hp engines offered by Mercury Racing.
Boaters who like a dose of racing heritage with their horsepower may want to learn more about Ilmor Engineering. The Roger Penske-owned company got its start building IndyCar race engines in the 1980s, partnering with GM Chevrolet, Mercedes, and Honda, and today has branched into NASCAR and ARCA. The company waded into the fray with marine racing engines in 2002 with the “SuperCat” Offshore Racing Series of the American Power Boat Association, and established a division to serve that segment in 2004. Ilmor began producing MV8 recreational marine engines in 2010.

Key Features

  • Standard electronic throttle
  • Standard closed-cooling, including exhaust manifolds
  • Close-fitting heat exchanger with integrated overfill tank
  • Performance-tuned aluminum air intake
  • Hard-anodized exhaust system
  • Molded hoses
  • Easy access service points, including oil filter courtesy tray
  • 75-hour oil service interval
  • 5-year/500-hour factory-backed limited warranty

Ilmor 483 HP MV8 7.4L with One Drive (on Formula 370 SS) (Sterndrive) Specifications
Horsepower 483-hp
Number of Cylinders 8 Cylinders

Ilmor 483 HP MV8 7.4L with One Drive (on Formula 370 SS) Captain's Report

Ilmor 483-hp MV8 7.4L with One Drive engine
Ilmor 483-hp MV8 7.4L

Ilmor MV8 7.4L Specifications

    Displacement: 7.44 liters

    Power Rating: 483-hp (360 kW @ 5400 RPM)

    Peak torque: 516 ft.-lbs. @ 4400 RPM

What’s Inside

Ilmor hand-builds this V-8 based on a GM 454 block, and uses plenty of interior components of Ilmor’s design, including forged steel crankshaft, rods, and pistons. This construction lies at the core of these engines’ durability, holding up their end of the deal with good low-end torque and substantial power.

Ilmor 483-hp MV8 7.4L with One Drive crankshaft
Ilmor’s forged crankshaft, rods, and pistons are a key component to its MV8 engines.

Cool Running

Multiple closed cooling systems use glycol-based coolant and heat exchangers to take heat away from components such as the exhaust manifolds and steering system, keeping everything operating within temperature tolerances for optimum performance and durability. Hoses for the system are molded in the shapes they need to be for the system, rather than using standard hose that is ungainly to bend. This procedure helps ensure proper seating on nipples without creating stress points, and also allows the hoses to mount more closely to the block to keep them out of the way.

Ilmor 483-hp MV8 7.4L with One Drive cooling system
A glycol-based cooling system keeps engine components running at optimal temperatures.
Ilmor 483-hp MV8 7.4L with One Drive
These bends, indicated by yellow arrows, are molded into this cooling hose, another way Ilmor helps ensure durability.

Exhaust Intelligence

The hard-anodized exhaust manifold is glycol-cooled to help prevent corrosion in the upper section. Additionally, Ilmor uses a clever design in the lower pipe, the only section of the exhaust manifold that is raw-water cooled. It is a separate casting mounted to the manifold with a cuff clamp, allowing for an easier (and likely much less expensive) change of that part if it should suffer corrosion. This section of the exhaust manifold is vertical which allows raw water to drain out after every use.

Ilmor 483-hp MV8 7.4L with One Drive manifold
On either side of the Ilmor MV8 engine is an exhaust manifold that is cast in two parts, so the lower pipe (indicated by yellow arrow), which is raw-water cooled, drains when the engine is off, and can be replaced easily.

Simplified Maintenance

Ilmor makes the more common maintenance tasks easier too. The engines have a recommended oil-service interval of 75 hours with a 150-hour interval for the sterndrive unit (or once annually). All service points are located on the top of the engine for easy access, and the oil filter is prominently placed within its courtesy tray.

Ilmor 483-hp MV8 7.4L with One Drive maintenance
Maintenance and inspection points are all designed for ease of access on the Ilmor MV8 7.4L, shown here installed on the Formula 370 SS.

One Drive

The One Drive is a sterndrive unit that looks a little larger than most, but for all the right reasons. For one thing, the lower unit was initially engineered by Yanmar to be coupled with high-torque diesel engines. The One Drive is fitted with forged gears for added durability and less wear-and-tear.

Ilmor 483-hp MV8 7.4L with One Drive designed
The One Drive was initially designed to link up with diesels, so it is a robust system for engines that produce substantial torque and operate in rugged offshore conditions.

One Drive Features

  • The entire housing is bigger because it contains the hydraulic transmission within the upper unit, which makes shifting in and out of gear incredibly smooth and quiet.
  • An electro-magnetic actuated clutch that’s quick and smooth, eliminating the clunk of cone clutches used by other sterndrive systems.
  • Larger water pickup and exhaust for better water flow and less engine backpressure.
  • Ilmor can wrap the upper housing of the One Drive to match the theme and graphics of the boat’s paint job.
  • The Ilmor One Touch® joystick system is designed to simplify the use of the One Drive propulsion system in close-quarters maneuvering around the dock.
  • The Ilmor MERLIN Digital Dashboard is a touchscreen on the helm that allows the user to access information about the engine system and even download data that may help service professionals schedule maintenance and head off problems.
Ilmor 483-hp MV8 7.4L with One Drive intakes
Larger water intakes, contrarotating propellers and larger diameter exhaust all mean better performance for the Ilmor One Drive.

One Drive Design and Build Details

Each drive is outfitted with precision forged gears for durability, counter-rotating propellers for superior acceleration and directional stability, and large rudder dimensions for enhanced handling on single and twin engine boats. The One Drive transom has a significantly larger exhaust output than comparable systems, minimizing backpressure for improved engine performance. The system is also equipped with the latest in active and passive corrosion protection, and is complete with power assisted steering and hydraulic trim.

Ilmor One Drive Specifications

    Maximum Input Speed: 6000 RPM

    Gear Ratios: 1.78 / 1.97 / 2.18

    Steering Angle: 30 degrees (to either side)

    Tilt Angle: 51 degrees (industry standard = 37 degrees)

    Trim Zone: –6 degrees to 10 degrees

    Propeller System: Contrarotating twin propellers

    Propeller Range: 22 / 24 / 26 / 28 inches

    Propeller Input: Counter clockwise

    Front Propeller Rotation: Counter clockwise

    Rear Propeller Rotation: Clockwise

    Clutch System: Hydraulic multi-friction plate

    Shift Control System: Electro-magnetic

    Power Steering System: Mechanical cable with hydraulic power assist (single engine installation)

    Trim / Tilt System: Hydraulic

    Exhaust System: Integral through hub

    Water Pick-up System: Integral through drive

    Anti-Corrosion System: Hard anodized and electronic active control

    Weight: 253 lbs. (with fluids)

Ilmor 483-hp MV8 7.4L with One Drive exhaust port
The Ilmor One Drive has a larger through-transom exhaust port, vented here in the hub of the aft propeller.

Quiet Operation

In the twin engine configuration on the 370 SS, the One Drive engages and disengages gears at two shifts per second, thanks to the hydraulic clutch that’s actuated electromagnetically. And because the transmissions are in the sterndrive unit, outboard of the transom, the whole setup runs quieter. The smooth shifting is especially helpful when a twin One Drive installation is used with the One Touch joystick system, which results in the system’s two sterndrives shifting in and out of gear quickly to deliver thrust in conjunction with the boater’s control. And, there is no clunk.

Ilmor One Touch Joystick System

For twin-engine installations of One Drive systems, Ilmor offers the optional One Touch joystick system. The joystick offers easy proportional control and the quick, quiet shifting delivers reliable low-speed maneuvering with the power and torque of the MV8 7.4L engines backing it up. The One Touch allows the boater to rotate the boat 360° within a boat length, as well as crab the boat sideways and diagonally.

Instant Joystick Response. While it actually has nothing to do with the joystick itself, it is when maneuvering the boat in tight situations with a strong current running that most operators need instant response from the propulsion system to joystick commands. Unfortunately, in drives that use a cone clutch, the gears must first be moved to neutral and then to the opposite gear before being engaged to follow the joystick’s command. This is this joystick/cone clutch “two-step” – and the clunk. Ilmor’s joystick and One Drive system shifts at two times per second, for virtually no delay between joystick demand and drive response.

Ilmor 483-hp MV8 7.4L with One Drive joystick
The Ilmor One Touch joystick and MERLIN Digital Dashboard are handy to the helm.

The Ilmor MERLIN Digital Dashboard Display

The MERLIN Digital Dashboard engine display shows a variety of engine data and can be equipped with autopilot compatibility. It’s a CAN-based touchscreen instrument panel that comes standard with One Touch joystick systems. Engine data can be rendered in analog gauge format, digital text, or even in a graphical treatment that shows the force vectors applied to the hull – including where the power is coming from – when the joystick is manipulated.

User Friendly. Directional and force-vector graphics that are not available on other digital systems. The control buttons on the frame of the screen let the user change settings when conditions are too rough for effective touchscreen use.

Ilmor 483-hp MV8 7.4L with One Drive dashboard
The MERLIN Digital Dashboard touchscreen display can show analog gauges, as well as shift indicators.

As a standard feature, the MERLIN also logs data to help boaters understand how to use their boats better, including real-time fuel-burn measurement, a great tool to help boaters dial in efficiency. The system can even provide engine data to service providers, to help them diagnose any problems that could crop up, and aid in troubleshooting.

Ilmor 483-hp MV8 7.4L with One Drive display
An indicator display on the Ilmor MERLIN Digital Dashboard display indicates the force vector on the boat (red arrow at center) resulting from the engine propulsion. It just may make you a better boat driver.

Engine Installation

The Ilmor throttle-and-shift control binnacle lets the propulsion system be programmed to optimize performance for the boat on which it’s installed.

Engine Room. On the Formula 370 Super Sport where we tested the Ilmor 483-hp MV8 7.4L with One Drive, the engine compartment is accessed from a switch at the helm that lifts the aft seats with a powered ram. Forward of the engines we find flip-down steps that allow easy access for daily checks and light maintenance, yet still offer access beneath. For more involved maintenance, the lift arm can be easily undone by removing a pin and the hatch can be opened fully.

Ilmor 483-hp MV8 7.4L with One Drive access
The Ilmor MV8 7.4L engines are accessible in the engine space of the Formula 370 Super Sport.
Ilmor 483-hp MV8 7.4L with One Drive running
Ilmor and Formula share a racing heritage and the Formula 370 Super Sport captures the essence of both companies with impressive performance.
Ilmor 483-hp MV8 7.4L with One Drive cowl
Because Ilmor partners with Formula (and other builders), the sterndrive cowl cover can be customized to match the paint job of the boat. Here’s one example.


We are struck by Ilmor’s level of detail in this system, and the company’s familiarity with the needs of a boat owner. But isn’t that what we have come to expect from almost anything Roger Penske touches? (Penske is also an ardent boat owner.) This marine propulsion system seems to exemplify his corporate culture of excellence.

Ilmor’s strength is its engineering and its experience with high-performance engines and drive systems – and their vulnerabilities. Most of its components are outsourced to quality vendors, thus reducing Ilmor’s expense in building a comparatively few engines for the marine market. And, that is one of its strengths: It is not saddled with old technology that is the company’s legacy.

The selection of the Yanmar sterndrive transmission and lower unit is a prime example of this quality outsourcing. By utilizing this drive and integrating it into a larger Ilmor propulsion system with engine, joystick, and MERLIN diagnostics, Ilmor has been able to create an excellent system for more refined maneuvering and cruising – and we suspect it is better and far more affordable as a result.

Ilmor 483-hp MV8 7.4L with One Drive
Racing fans have watched Roger Penske in the pits at Indy and other venues monitoring and coaching his team of professionals for decades. Few people bet against his race cars.

Warranty. The system has a 5-year/500-hour limited warranty. This is putting Ilmor’s money on the table where it counts.

While the instant shifting, no clunk, MERLIN joystick vector graphics, cool-looking engines with its painted aluminum air intake, and its 483 horses, are all terrific features, we think that the system’s potential for reliability and high owner satisfaction is its most important attribute.


Already a member?