Update: There was apparently a bug with the video embed in the article showing the race engine. We have updated the article and the video should be visible, but if it still doesn't show up, you can see the video at this link: https://motorsport.tv/embed/1bzI1j1a-testing-avl-s-groundbreaking-hydrogen-race-engine
Internal combustion engines aren't dead. Aside from the possibilities of synthetic fuels compatible with present-day mills, development is also taking place on hydrogen-powered combustion engines.
Last December we got an overview of the 2.0-liter turbocharged four-pot currently in development with AVL Racetech. Now we have an in-depth look at exactly how the company is using hydrogen to make a powerful, noisy, and sustainable combustion engine for the future.
Our colleagues with Autosport recently toured AVL Racetech's facility in Austria, where the four-cylinder is being dyno-tested. A 13-minute video confirms it sounds every bit like a small, high-output engine should – howling its heart out as the exhaust pipes glow cherry red from the controlled explosions within the cylinders. This particular dyno session sees the engine reach a peak output of 405 horsepower at 6,500 rpm, with maximum torque reaching 375 pound-feet at 4,000 revs. Previously, the engine clocked 410 hp but with just 368 lb-ft of torque.
As the video states, one wouldn't necessarily know this engine was burning hydrogen by sound alone. And it would take a keen eye to spot visual differences in the various engine components. It is, however, a very different engine versus one you'd find in your average passenger car.
"Hydrogen is a very reactive molecule," said Paul Kapus, manager of spark-ignited engines and concept vehicles at AVL Racetech. "It likes to ignite on every surface you can imagine – hot surfaces, hot oil droplets, too-hot spark plugs, hot valves. There is a big risk of preignition."
Senior Development Engineer Nilton Dinaz further explains the challenges the company faces. "Hydrogen is a really peculiar fuel. It needs to moderate the combustion process itself because it burns blazingly fast. That’s why we approach with water injection."
High pressure is a fact of life with hydrogen engines. The intake manifold and fuel rails are specifically designed to use the fuel, and lest we forget, it's a very dry fuel versus normal pump gas, which is a liquid. The fuel injectors require lubrication, and there's even a hydrogen-specific turbocharger involved. Pressures are very high, so the engine's basic construction needs to handle that pressure without blowing apart.
But the system works well. The video shows the mill cranking out power similar to Mercedes-AMG's heroic turbo-four, all while using an abundant fuel source. The next phase will see the engine tested on the track in racing conditions. And if all goes well, there could be hydrogen-engined cars racing at Le Mans in 2026.
