The McLaren M838T: Building the world's "greenest" supercar engine

The nervous wrist-ward glances, muttered last-minute instructions, obsessive tidying and palpable tension said it all: Ron Dennis was coming to visit. And the engineers in charge of building the engine for Britain’s latest supercar were anxiously hoping that their new facility would be up to the McLaren chief’s legendarily exacting standards.

He was also particularly pleased with his team’s work on improving the sealing integrity of the engine by eliminating the T-joints typically used to join the cylinder heads to the engine block. To test this, and to make sure that the engine wouldn’t leak, Yates’s team put it through an exceptionally tough thermal shock test. The engine was started at an ambient temperature, put up to full power almost immediately, left running at around 115°C and then crashed back to 20°C. Repeated over and over again, this test gives the structure of the engine an extremely hard time, explained Yates. ’It expands internally faster than it does externally. All of the sealing joints and interfaces within the engine and the moving parts have got to survive that very arduous test.’