Here are several pictures of drain-cock, both for the seawater circuit and for the fresh (eg. water and glydol) water circuit.
My engine (NC33 1977-1978) is a Ford 2712E marinizes by Gustavson of Stockholm.
– Chauffe-eau vanne moteur_10023.jpg shows one drain at the bottom of the coolant water (fresh water) tank. This tanks exachange heat betzeen fresh water and seawater.
– Purgeur_1478.JPG is taken from port side, front side of the engine, the alternator being removed to show one drain (green arrow). One can guess the beaing axis for the alternator at the opposite side of the arrow, very rusty at that time. And the alternator belt too.
– Purgeur_1490.JPG is shot from port side toward the rear of the engine. One can guess the stainless steel exhaust elbow. The drain will certainly remove saewater for the top of exaust manifold and the marinistation part by Gustavson
– Purgeur_1497.JPG is another view of the drain that lies behind the alternator.
Hope it helps,
Yves 5Naïla of Burnham, NC33 MkII #484)