The subject of the invention is a cast part with high static mechanical strength, and for fatigue and hot creep, made of aluminum alloy of composition: Si: 3-11%, preferably 5.0-9.0% Fe <0.50%, preferably <0.30%, preferably still <0.19% or even 0.12% Cu: 2.0-5.0%, preferably 2.5-4.2%, preferably still 3.0-4.0% Mn: 0.05-0.50%, preferably 0.08-0.20% Mg: 0.10-0.25%, preferably 0.10-0.20% Zn: <0.30%, preferably <0.10% Ni: <0.30%, preferably <0.10% V: 0.05-0.19%, preferably 0.08-0.19%, preferably still 0.10-0.19% Zr: 0.05-0.25%, preferably 0.08-0.20% Ti: 0.01-0.25%, preferably 0.05-0.20% other elements <0.05% each and 0.15% in total, the rest aluminum. It more particularly relates to cylinder heads for supercharged diesel or petrol internal combustion engines.