Stellantis’ All-new 2.0-liter Hurricane 4 Turbo Engine Packs Big Power With Race Proven Combustion Technology

Stellantis debuts the all-new 2.0-liter Hurricane 4 Turbo four-cylinder engine that combines advanced design and engineering innovation with performance combustion technology. This new engine generates more horsepower and torque than many comparably sized and larger engines while also delivering better fuel economy and lower emissions.

The compact 2.0-liter Hurricane 4 Turbo’s output – 324 horsepower at 6,000 rpm and peak torque of 332 lb.-ft. from 3,000-4,500 rpm – gives it the muscle to confidently propel a variety of vehicle sizes, ranging from compact to full size.

“The Hurricane 4 Turbo name is appropriate because this engine packs a punch, as the variable geometry turbocharger, the high-performance combustion and the twin fuel system deliver 162 horsepower per liter of displacement,” said Micky Bly, Stellantis senior vice president and head of Global Propulsion Systems. “The clean sheet design gives our customers a powerful, refined, smooth-running engine that uses 10% less fuel to deliver 20% more power than our current 2.0-liter DOHC I-4.”

The first application for the Hurricane 4 Turbo is the 2026 Jeep® Grand Cherokee. The engine design includes flexibility for conventional, hybrid and plug-in hybrid powertrains.

Performance Proven Combustion Technology
Central to the Hurricane 4 Turbo’s combination of plentiful power with benchmark fuel efficiency is the use of turbulent jet ignition (TJI) combustion technology, which is used in global, top-tier racing engines.

The innovative, passive TJI system in the Hurricane 4 Turbo uses a spark plug to ignite a small amount of fuel in a cup-like pre-chamber atop each cylinder. The burning fuel expands and jets into the combustion chamber, triggering a faster and more complete burn of the air-fuel charge, which enables better performance and fuel efficiency.

Stellantis engineers combine the TJI combustion and turbocharging with a Miller Cycle operating strategy that closes the intake valves early to optimize engine efficiency and reduce emissions. This enables the Hurricane 4 Turbo to use a power-generating 12:1 compression ratio without risk of engine-damaging knock (early ignition) while using regular (87 octane) gasoline.

Each cylinder of the Hurricane 4 Turbo has two spark plugs, one for the TJI chamber and one for the combustion chamber. Ion sensing is used for misfire detection.

Efficient Power and Performance
The Hurricane 4 Turbo uses both port fuel injection and high-pressure (350 bar/5,076 psi) direct fuel injection. The engine controller deploys either fuel system or both combined, depending on engine status and driver demand:

• Cold start: Both fuel systems are active to promote quick light-off of the catalytic converter
• Idle and low loads: Port fuel injection is active to minimize noise, vibration and harshness (NVH) and to reduce particulate emissions
• Typical power loads: Both Port fuel and Direct fuel injection systems are active with varying ratio based on driver demand
• Peak power/maximum torque: Both systems are active with the direct injection system providing most of the fuel

Adding to the Hurricane 4 Turbo’s performance is a variable geometry turbocharger that features active vanes inside the housing, delivering up to 35 psi (2.4 bar). It provides significant boost at low engine rpm for power and torque during launches, acceleration and cruising, with 90% of peak torque from 2,600–5,600 rpm. Pressurized air from the turbocharger passes through a liquid-to-air charge-air cooler on its way into the engine, reducing temperature for a denser, more powerful intake charge in the combustion chamber.

The variable geometry design enables Stellantis engineers to achieve high power density without compromising low end torque and transient performance, while keeping the overall package compact, compared with a conventional twin-scroll turbocharger.

Further enhancing engine efficiency, the Hurricane Turbo 4 uses an electric-powered water pump and a variable displacement oil pump to reduce parasitic losses.

Strength in a Solid Foundation
A die-cast deep skirt aluminum block provides a solid foundation for the Hurricane 4 Turbo. The single-piece casting is produced by Stellantis, which also produces the die-cast aluminum oil pan and timing cover.

The engine’s structural stiffness is enhanced to help minimize NVH. The Hurricane 4 Turbo features thicker cylinder bore walls (24% thicker compared with the current 2.0-liter DOHC I-4), and larger main and connecting rod bearings on the crankshaft. A structural windage tray and balance shaft assembly is mounted low in the engine. A viscous crankshaft damper helps reduce vibrations.

The aluminum cylinder head contains four valves per cylinder and overhead camshafts. The TJI chamber is press-fit into the center of each combustion chamber for simplified assembly. Variable intake timing is adjusted quickly by an electric camshaft phaser, which delivers smoother startups. Exhaust valves are sodium filled for heat management.

Just like Stellantis’ award-winning Hurricane Twin Turbo I-6 engines, the Hurricane 4 Turbo has an ultra-thin, low-friction Plasma Transfer Wire Arc (PTWA) coating in the cylinder bores. Compared with conventional iron cylinder liners, the PTWA coating has 10 times the wear resistance.

The PTWA process, adapted from the aerospace industry, melts a steel alloy wire at 2,300 degrees Celsius (4,150 degrees Fahrenheit), producing microscopic particles sprayed onto the cylinder walls at high velocities, where the particles splat-cool to form the coating and create a physical bond to the cylinder bore. Honing the surface gives it a super-fine cross hatch pattern with controlled micro porosity for oil retention. The spray process leaves more aluminum between the cylinders for better heat transfer and engine cooling.

The Hurricane 4 Turbo is assembled in Dundee, Michigan, with production being added in Kokomo, Indiana, in the future. The aluminum block is cast and the cylinder bore lining is applied at Stellantis facilities in Kokomo, Indiana.

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