NEWS
Jeep’ s Huricane 4 is full of the best tricks
A turbocharged 2-litre four-cylinder to get excited about
n New engines are scarce, ones that pique your interest are truly rare. And while a turbocharged 2-litre four-cylinder seems an unlikely motor to be excited about, trust us, it’ s worth your attention.
Jeep’ s new Hurricane 4 produces 324hp at 6000rpm and 450Nm of torque from 3000 to 4500rpm. More than most similarly sized and boosted engines. How it does that is where things get interesting. The headline technology is what Jeep calls Turbulent Jet Ignition( TJI); prechamber ignition, just as we see in F1 and other top-tier race engines.
The Hurricane engine has a little perforated pocket at the top of the combustion chamber in each cylinder. Within that, a spark plug ignites a small but rich mix of fuel and air. As it burns, the mix expands and jets out through the perforations into every corner of the main combustion chamber. This process results in a faster and more complete burn of the fuel, and therefore better performance and efficiency.
The pre-chamber ignition requires the Hurricane to double up on two elements, pairs of which you only usually see on the most exotic of engines. It’ s a twin-spark engine, with one spark plug in each cylinder dedicated to the pre-chamber ignition, the other to ensure that as much of the main combustion chamber is put to good use.
The Hurricane also has two injectors, a direct one that feeds the TJI system and another located in the intake port to supply a lean mix through the inlet valve. Like the second spark plug, the supplementary port injector guarantees flame propagation spreads throughout the cylinder. The secondary injector is also used to minimise noise and vibration.
The technology within Jeep’ s Hurricane engine also includes a variable-vane turbocharger, a liquidto-air intercooler, an electric water pump, a variable displacement oil pump, variable intake cam timing, a structural windage tray and plasmacoated cylinder bores. Let’ s hope that Stellantis, the umbrella firm that owns Jeep, puts the Hurricane 4 in something more exciting than the Grand Cherokee.
A variable-vane turbo and prechamber ignition are just some of the tech highlights in Jeep’ s latest four-cylinder engine
8 The Engine Rebuilder Issue 04