By Ben Mozart:
The race engine requires a precise mixture of air and fuel, approximately 13.0:1 by weight ratio.
But the power it makes depends upon how well the mixture is emulsified and atomized. How well it is delivered through the intake manifold runners and cylinder head ports. And it’s ability to negotiate the intake valves and to swirl in the combustion chambers, which are an extension of the ports, and to occupy the cylinders.
For most of us, arranging and controlling the movements of the gases in the cylinder head ports are beyond our imaginings. Is the air-fuel mixture moving efficiently in the intake tracts or clinging, vexingly, to its sides? If so, how could it be reintroduced into the air stream? And further downstream, how is it negotiating the short turn, the five valve-angles in the throat, and does it demonstrate swirl as it moves into the combustion chamber?