[lkchris]

Usual purpose of secondary air is to introduce oxygen into the exhaust stream so that unburned fuel is combusted. Spark not required at temperature encountered. Unburned fuel a product of rich mixtures required at cold start. Blower turns off very soon after start as engine warms, consequently no longer requiring rich mixture.

So, any air flow in the cylinder head would be between exhaust valve and exhaust manifold, I.e. in exhaust port.