Ice tank charge air cooling to maximise intake air density

Compressing the air in the e-compressor and the turbocharger compressor increases its pressure but also heats it up, which offsets the gain in air density forced into the engine. To effectively cool the air charge down without introducing a large and un-aerodynamic air cooling duct, a water charge air cooler supplied by a tank of iced water has been used. The ice quantity and starting water temperature has been optimised to ensure just enough ice/water mass is carried to control the intake air temperature over a record run.

E-compressor (electric supercharger) for enhanced transient response

The turbo lag of the large single stage turbocharger is offset by the use of the electric supercharger which supplies pre-compressed air to the turbocharger’s compressor inlet when the engine accelerates through lower rpm.

Single stage turbocharger with 5:1 pressure ratio for maximum torque and power

A single turbocharger delivers high levels of boost pressure for maximum engine torque and power, whilst still being easily packageable under the hood of the tractor. High compliance expansion joints and 3D printed Inconel sections have been engineered into the exhaust manifold to cope with the extreme temperatures of up to 1000°C, and a high flow wastegate keeps the boost pressure under control.

Water injection to control intake manifold air temperature

A water injection system was used to good effect on the JCB Dieselmax LSR streamliner car in the heat of Bonneville, and a similar system has been used here to reduce in-cylinder temperatures and further minimise the risk of the pistons and exhaust manifold overheating.

Air pulse system for enhanced transient response

To further accelerate the turbocharger onto boost, Ricardo engineered an air pulse system that uses high pressure compressed air injected ahead of the turbocharger turbine. A strategically timed injection of pulses of air rapidly increase the rotational speed of the turbocharger, to avoid any “bogging down” during gear changes and acceleration.

Ricardo High Speed Diesel – Race (HSDR) diesel combustion system with low compression ratio and 2500bar injection pressure

A key challenge of increasing the specific power of a diesel engine is the resulting increase in in-cylinder pressure (Pmax), which if not controlled, will seriously damage the engine structure. Ricardo specified a low (by diesel standards) compression ratio of 12:1 to limit Pmax. The piston bowl shape has been carefully optimised to work with the 2500bar high flow fuel injectors to ensure rapid mixing of fuel and air, to deliver extreme power as efficiently and cleanly as possible. A coolant pre-heat system and intake air heater is used to prevent white smoke under cold start conditions.

High oil flow piston cooling jets, custom made using additive manufacturing

The engine’s pistons are kept cool by directing powerful jets of oil at the underside of the piston crown. The oil jet has been uniquely designed for each of the 6 cylinders to correctly target the piston whilst avoiding collision with the fast-rotating crankshaft and connecting rods. 3D metal printing achieved the complex geometry of each jet ensuring accuracy and repeatability of spray positioning.