New valve tech can slash fuel use

A UNITED KINGDOM AUTOMOTIVE ENGINEERING research company believes its intelligent valve technology (iVT) system can cut fuel use by 5% in a typical heavy truck engine.

And, as an added bonus, Camcon Automotive says its system requires vastly simpler and less expensive exhaust aftertreatment systems to meet emissions regulations.

For a typical New Zealand truck, travelling 150,000km per year at an average of 2.1 kilometres per litre, the fuel saving would represent around $4800 worth of diesel in 12 months.

Camcon Automotive iVT takes the concept of variable valve timing to a level beyond existing systems, by offering virtually infinite control over lift and duration. In its design, every valve has an individual cam lobe and shaft, turned by its own digitally-controlled electric actuator.

This means lift and/or duration can be seamlessly varied for optimal efficiency under all conditions, while exhaust gas recirculation, ondemand cylinder deactivation and engine braking can be easily accomplished without extra hardware.

In multivalve heads, the variable operation of individual inlet valves can be set to precisely match a cylinder’s instantaneous breathing demands, introducing swirl or tumble (or a hybrid of both conditions) to the incoming air.

A key feature of iVT, says Camcon, is that it doesn’t require a redesign of an engine’s cylinder head, so the size and shape of ports and valves remain standard. Roller follower arms enable desmodromic operation (positive opening and closing), meaning that conventional valve springs can be dispensed with.

In a heavy vehicle diesel engine, says the company, catalysts can be maintained at their optimum operating temperature over a greater proportion of the drive cycle and, while iVT cannot eliminate aftertreatment equipment entirely, it can reduce its size, cost and weight. For instance, thanks to the system’s greater optimisation of emissions control, a truck would not need to use as much AdBlue.

Neil Butler, technical consultant for Camcon Automotive, says iVT is effectively breaching a final frontier in internal-combustion technology: “All key combustion process parameters have been under digital control for some time now. But breathing has been stuck under the control of increasingly complex but essentially mechanical variable valve train systems. iVT is as big a leap forward as the change from carburettors to electronically controlled fuel injection.

“Another factor to consider is that heavy duty trucks require long ranges as well as rapid unloading and loading – so electrification is a lot further away than it is in the passenger car industry. We believe iVT can reduce running costs, dramatically improve emissions and require no change to the current refuelling infrastructure.”

Looking even further into the future, Camcon Automotive’s vision is to incorporate a suite of software that allows iVT to be calibrated through machine learning, combining hardware and software in one package, resulting in the most optimised internal combustion engine yet – the fully digital engine.

T&D