A study of mechanical variable valve operation with gasoline–alcohol fuels in a spark ignition engine

Investigation of the effects of iso-butanol additives on spark ignition engine fuelled with methanol-gasoline blends

“…Alcohols are considered as alternative fuels for internal combustion engines and have been investigated comprehensively [1][2][3][4]. Adding alcohols into gasoline or diesel allows the fuel to have a complete combustion with the present of oxygen which increases its combustion efficiency and reduces greenhouse gas emission.…”

Insights into Stoichiometric and Lean Combustion Phenomena of Gasoline–Butanol, Gasoline–Ethanol, Iso-Octane–Butanol, and Iso-Octane–Ethanol Blends in an Optical Spark-Ignition Engine

“…Butanol itself has been studied in the literature much less than ethanol and mostly in PFI engines as well; some benefits in terms of blending have been reported (e.g. better stability) but trends have been sensitive to equivalence ratio, spark timing, engine temperature and valve overlap (Malcolm et al, 2007;Todd et al, 2010;Szwaja and Naber, 2010;Dernotte et al, 2010;Merola et al, 2011Merola et al, , 2012Tornatore et al, 2013;Cairns et al, 2013;Deng et al, 2013;Brequigny et al, 2013). In contrast, very few alcohol-blended combustion studies have been conducted in latest technology Direct Injection Spark-Ignition (DISI) engines that are more sensitive to fuel properties than PFI engines.…”

Design and manufacture of high performance hollow engine valves by Additive Layer Manufacturing

“…By implementing a simple web structure within the hemispherical design, the maximum stress is significantly reduced, although the weight reduction is smaller (20.3%) this provides a more robust design, well within the maximum fatigue stress limit. Although this weight saving is less than achievable by substituting for titanium (theoretical 55% weight saving), the good mechanical properties of Inconel 718 at temperatures above 600 o C, and the improved durability over titanium [9], make this a very attractive alternative to titanium, making available a larger range of cam phasing [8] and thus offering reduced emissions and more environmentally friendly power delivery [7], enabling powertrain manufacturers to move nearer the global targets set for emissions [1].…”

“…For example, late closure of the intake valve in a premixed charge compression ignition diesel engine has been identified as a potential route to greater control of combustion phasing and so emissions reduction [7]. While one limiting factor in the optimisation of variable valve timing is piston/valve clash which limits the range of cam phasing available [8], a lighter valve could extend those limits as its lower inertia enables a more aggressive cam phasing.…”