2023 Mercury Racing 400R Outboard Engine Revealed

Surprisingly, the new performance-honed version of the 5.7-litre quad-cam V10 powerhead does not produce more power than the more pedestrian, but still impressive, Verado version on which it is based.

But it’s the magic that Mercury Racing does on the intake side of the engine that will make all the difference.

Key to that is a Mercury Racing-developed 92mm intake that’s unique to this engine, as well as a tuned intake to maximise airflow and power delivery.

The new throttle body also uses a Mercury Racing servo motor to control fuel flow more precisely, which in turn makes the throttle more responsive.

Wide-open throttle for the Mercury Racing 400R is at 6600rpm, 200rpm higher than the 400hp V10 Verado version.

The engine also gets a re-engineered midsection that provides more strength and stability at speed than Mercury’s standard ‘Advanced Mid Section’ unit used for the Verado, using stiffer engine mounts and heavy-duty guide plates.

The engine also comes with the option to fit a tie bar, an important element in multiple engine installations.

Below the water the Mercury Racing 400R will offer the option of a ‘5.44 HD’ heavy-duty gear casing that is better suited to heavy bay boats and multi-engined centre consoles, sitting lower in the water and offering better holeshot performance from a 1.60:1 ratio compared with the V10 Verado’s 2.08:1.

If your boat’s not big and heavy, Mercury Racing will offer a surface-piercing lower leg aimed at boats with a top speed of at least 74 knots. It uses a lower water pick-up and a crescent-shaped leading edge above the torpedo to make it more slippery and stable at higher speeds.

It also uses a 1.60:1 gear ratio.

Along with the new lower legs, Mercury Racing has developed a new 15-inch Ventera propeller to power the recreational boats that will tap the new engine’s performance.

According to Mercury Racing, the four-blade prop was engineered specifically to carry more load with greater efficiency at high speeds and in semi-surfacing installations.

The new engines will come in either black with red highlights, or white with red and black highlights – or whatever custom colour their new owners desire.

Mercury Marine Australia was contacted for information on local pricing and availability.

The new engine is a replacement for the supercharged 2.6-litre in-line six-cylinder 400R engine that is only a few kilograms lighter than the new V10 versions, and revved out to 7000rpm at maximum wide-open throttle.

The new engine’s wider range of shaft lengths means it can be fitted to more boats in multiple-engine installations than the previous generation.

The new V10 version also runs on 91RON fuel, making it cheaper to run than the old version that relied on 95RON premium unleaded.

Specifications
Model: Mercury Racing 400R
Power: 400hp
Operating range: 6000–6600rpm
Engine type: 64-degree V10 quad-cam 40-valve
Displacement: 5.7L
Induction: Naturally aspirated
Fuel: 91RON
Alternator: 150A
Throttle and shift: Digital
Midsection: Racing Advanced Midsection (rear tie bar bracket opt)
Shaft length: 508mm (20-inch), 635mm (25-inch), 762mm (30-inch), 889mm (35-inch)
Gearcase: Sport Master/5.44-inch HD
Gear ratio: 1.60:1
Weight: 315kg (dry)