Guinness World Record at VNL heavy truck launch

Volvo Trucks unveiled the new VNL heavy truck for over-the-road operations by boxing it up like a toy and letting a three year old boy open it up for a Guinness World Record. The unboxing may have been a slick publicity stunt, but the tech under the hood of this big machine is no gimmick.

In a promotional video (below) for the unveiling of the new VNL series of commercial heavy-duty semi-trucks, Volvo let three-year-old truck fanatic Joel Jovine unbox the tractor-trailer. This set a new Guinness World Record for the largest item ever unboxed, as witnessed by Guinness World Records adjudicator Michael Empric.

Under the hood of the the new Volvo VNL is a new piston technology that improves fuel burn and thus power delivery and efficiency in a simple, novel way. This is called a “wave piston” and is a simple change to the piston head in order to improve fuel-air mixing within the combustion chamber.

In normal diesel engine design, fuel and air injectors are located at or near the top of the cylinder. Fuel is sprayed towards the sides of the piston as air is compressed during the piston’s upward travel. The pressure ignites the fuel and the resulting flames swirl along the combustion chamber walls at up to 50 meters per second.

As flames spread along the piston bowl (top of the piston), they collide with one another at an angle of about 180 degrees. Those colliding flames compete for oxygen, pulling it from around the chamber’s walls, under-utilizing the oxygen at the center of the cylinder.

With Volvo’s new “wave piston” design, the cylinder’s bowl-shaped head is changed to include “waves” along the edge that disrupt the usual travel of the flames, stirring them so that the oxygen at the center of the chamber is more utilized, improving burn efficiency. This translates to better power output on each stroke for the same amount of fuel and air, meaning greater efficiency overall. The video below illustrates how this new wave piston head works.