Britain's Camcon Automotive just changed the rules for what an internal combustion engine can do. They have developed a new type of valve train called Intelligent Valve Technology (IVT). IVT uses powerful solenoids to open and close engine valves. This eliminates camshafts and their timing belts and allows engineers to optimize engine operation like never before.
The Old Way
Internal combustion engines breathe in fresh air and expel wasted exhaust gases. The airflow through the engine is orchestrated by intake and exhaust valves which are controlled by one or more camshafts. In turn, camshafts are driven by gears or timing belts that connect directly to the engine's crankshaft. This whole technology has been around in one form or another over 100 years.
The Digital Way
A digital valve train is much less complicated than an all-mechanical valve train since no camshaft, timing belt, valve rockers or anything else is needed to open and close the valves. Instead each valve has an electric actuator that works a mini-camshaft, opening and closing each valve independently from the others. Overall, it's a faster way of adjusting to an engine's power demands. It's a cutting edge solution but very simple in execution.
What Took So Long?
While fully digital valve actuators have just been developed, the basic technology has been implemented in other ways. Variable Valve Timing (VVT) is a version. Honda's VTEC system is VVT and it has been used in Preludes, Civics, Integras, and Accords. BMW uses VVT in it's VANOS technology and Nissan has its N-VCT system.
The problem is that an all-mechanical VVT was not a perfect solution. A VVT engine changes its timing either through "cam-changing," via an electronic control unit, or a "cam phaser" that adjusts the angular position of the lobes on the camshaft. According to Mullahey Chrysler of Paso Robles, CA, by adjusting the ignition timing, VVT can tweak the engine to suit different driving demands, from full power under heavy acceleration to full-efficient cruising. However, it takes time for a cam phaser to shift the lobes into new positions, especially at low speeds. The engine keeps firing while the lobes are repositioning and during that time the camshaft is opening and closing in sub-optimal conditions.
Fully Digital is Better
Camcon's digital IVT involves no such compromises. This tech repositions the lobes as fast as an engine can change ignition timing, and so there's no gap of time where the camshaft is in a compromised position. It can adjust quicker than VVT and to a wider range of settings for timing, duration, and lift. It doesn't tie the engine into being better at a certain part of its powerband and worse at another the way conventional camshafts do.
When Will It Be Available?
Camcon Automotive is currently working with several manufacturers and testing is being done. We should be seeing this technology is the near future, though.
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