AvtoVAZ engineers have developed and patented a cylinder head design that should improve the operation of a gasoline engine at low speeds and partial loads. The unusual nature of the solution is that to enhance mixture formation, the developers did not add complex mechanisms: the desired effect is created by an aerodynamic protrusion in the intake port and a sharp edge near the valve seat.
The first element directs the flow of the fuel-air mixture into the gap between the intake valve disc and its seat. A sharp edge on the opposite side of the channel, formed during the machining of the seat bore, causes flow separation and increases turbulence. As a result, a vortex should intensify in the combustion chamber, which promotes mixture mixing.
The design is based on the cylinder head used in the Lada Vesta. The authors expect to improve fuel efficiency and toxicity performance at low speeds and partial loads, where the effect of charge motion organization is particularly important, by changing the intake gas dynamics.
AvtoVAZ engineers also changed the geometry of the combustion chamber. Part of its volume has been transferred from the head to the combustion chamber formed in the piston, which should contribute to the removal of some heat through piston oil cooling and reduce the thermal load on the head. The contour of the chamber on the lower surface of the head has a shape that the patent compares to a "butterfly".