Siamesed definition
Arrangement of ports when intake or exhaust valves are in pairs which allows two-into-one passages to be cast into the cylinder head . For example, with the usual valve arrangement in a four-cylinder engine the head can be designed so only two ports connect to the intake manifold and only three to the exhaust manifold . Also, when the engine cylinders are connected solidly together (as in the Vega block) instead of being totally surrounded by water jackets , the cylinders are said to be siamesed.