Authors:-Robert Spillane, Dr Don Law
Abstract:-Emissions and fuel consumption are becoming a defining factor of a vehicle performance. As emission legislation becomes increasingly strict, current internal combustion chambers are limited by mechanical camshafts and their level of fuel consumption and emissions are no longer acceptable. The next logical step is to improve the control over the ICE and this can be accomplished by expanding the range of valve events with fully variable valve trains (FVVT). This report provides a brief literature of the limits and problems of mechanical camshafts, the development of partially variable valve technology, such as phase shifting the valve timing and multilobe camshafts. The focus then shifts to how electrohydraulic and electromagnetic systems can provide FVVT and the reduction in fuel consumption and emissions they provide. FVVT offer opportunities to implement other technologies such as Controlled auto ignition (CAI) and cylinder deactivation. The theory and results of these techniques are also covered.
Keywords: FVVT, Variable Valve Actuation (VVA), Controlled auto ignition (CAI)
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