The Maserati MC20's new Nettuno V6 is a high-tech showpiece

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The Maserati MC20's new Nettuno V6 is a high-tech showpiece

The brand's first new V6 in decades boasts twin turbocharging, pre-combustion ignition, and more than 600 horsepower.

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What's more, the Nettuno is designed as two three-cylinder motors working off a common crank containing four main journals and three rod journals that each hold two pistons. As an even-fire engine, the crank experiences a firing event every 120 degrees. These principles could all have been lifted from the Alfa Romeo 690T.

We asked Maserati chief engineer Matteo Valentini about the F154 connection. He replied, "Of course it has solutions you can find on other engines, but please don't be fooled by the external shape of the engine." He admitted Maserati engineers took advantage of knowledge throughout Fiat-Chrysler – the same resource sharing one finds at other OEM conglomerates like General Motors and the Volkswagen Group. Yet, stressing the in-house, beginning-to-end development of the new V6, Valentini said the engine "is designed by us, developed by us, produced by us, and assembled by us."

The Nettuno shares its architecture with Alfa Romeo’s 690T but is cast by a different supplier, and the block "has different content inside, it has a different bore, [and] it has different oil ducts." In his assessment, the heart of Maserati going forward is "a brand-new project that makes use of all the experience we had in the past."

Pre-chamber ignition, which comes in active and passive forms, generally uses one spark plug. Maserati's passive method fills in the pre-chamber's weak spots by using two. One plug sits in the 1.5-cc pre-chamber. A second plug pokes its electrode into the side of each oversquare chamber. This makes the Nettuno a twin-spark engine with dual injection; port-injection works on a 6-bar fuel rail, direct-injection on a 350-bar fuel rail. Maserati's patent application for the tech says it enables a 15% increase in compression ratio and a fuel consumption reduction of up to 30%. (Before anyone accuses Maserati of stealing Alfa Romeo's twin-spark cleverness, Maserati was making twin-spark engines as far back as the 1950s for the inline-six in the 250 F race car, and later for road cars like the Mistral that also featured dual overhead cams, fuel injection, and hemispherical combustion chambers.)

Maserati's press releases have explained the second plug "[ensures] constant combustion when the engine is operating at a level that doesn’t need the pre-chamber to kick in." We asked Valentini about the performance parameters that activate the pre-chamber ignition, he told us the system isn't binary; rather, the pre-chamber ignition always contributes.

"At mid and low loads," he said, "the standard injection is predominant. When you go from mid to high loads, the prechamber takes the advantage, and we … play with the spark advance in order to give the right priority to one of them."

We asked how much power the pre-chamber ignition adds, he said a touch more than 100 horsepower. The Nettuno goes from roughly 510 horsepower on standard injection to 620 or 630 with pre-chamber assistance.

Speaking of power contributions, the Nettuno's turbos have been programmed to wind up to 3 bar (43.5 psi) so far and have electronically controlled wastegates. As for why the turbos hang off the side instead of being nestled between the cylinders, Valentini said the team looked into a hot-vee setup, but couldn't find a simple, reliable solution able to hit the targeted 210 horsepower/liter. The traditional arrangement is cleaner and creates a lower center of gravity.