Performance might match JCB’s diesel engines, but 74 hp (55 kW) won’t go very fast on the salt. Instead, each of the two hydrogen engines powering the JCB Hydromax has been seriously worked on, increasing their outputs to 800 hp (597 kW) apiece. That required doubling the engine speed to a heady 3,800 rpm, replacing the pushrod valves with double overhead camshafts for better control over timing, and moving to direct fuel injection at much higher pressure than the production engine. JCB also dry-sumped the engine, cut weight, and improved cooling. The JCB Hydromax even uses two ice tanks to cool the air leaving the turbocharger, down from 392° F (200° C) to below 50° F (10° C).

406.320

Behind the wheel yesterday was RAF Wing Commander Andy Green, who is no stranger to the record books. He also drove Thrust SSC through the sound barrier in 1997, and in 2006, he set a diesel-powered land speed record, again with JCB, with the JCB Dieselmax, which topped out at 350 mph (563 km/h). (Green was also set to drive Bloodhound, should it have happened.)

With a combined 1,600 hp (1,193 kW) and 2,600 lb-ft (3,525 Nm) and all-wheel drive, the JCB Hydromax set a speed of 400.623 mph (644.74 km/h) yesterday, followed by a run in the other direction of 412.135 mph (663.27 km/h) for a two-way average of 406.320 mph (653.91 km/h).

That’s more than twice as fast as the previous hydrogen combustion land speed record of 185.5 mph (298.53 km/h) set by the BMW H2R in 2004 (using the rather power-limited V12 mentioned earlier). And it’s a lot faster than the fastest hydrogen fuel cell speed record as well, which stands at 303 mph (488 km/h), set by the Venturi Buckeye Bullet 2 in 2009. It also beats the fastest EV land speed record, which was set in 2016 by VBB3 at 341 mph (549 km/h). However, the fastest wheel-driven land speed record belongs to the nitromethane-fueled V8s of Challenger II, which set a record of 449 mph (722 km/h) in 2018.

“Bonneville is the spiritual home of the world land speed record, and JCB Hydromax has just written itself into that history,” Green said. “The car was terrific—stable, strong, and fast. Setting a world land speed record with hydrogen power, twenty years after Dieselmax, is a huge privilege. This record is a huge achievement by a world-class team and superb technology.”