About this detail of the Tiger
The Tiger 1 had two large radiators for cooling the engine. They stood in the rear of the sponsons, one on each side.
These diagrams give the basic dimensions of the radiators. The connections for inlet and outlet pipes were on the rear side. There were two projections with four rubber feet on the front side.
The left-side radiator had a black filler cap on top.
The right-side radiator had a safety valve, facing forward. Therefore, when a Tiger's engine overheated, steam would appear from the large right-side grille on the engine deck.
The safety valve is numbered (13) on the Tiger Lubrication Chart. It is to be inspected every 2000 km.
Hot water flowed out of two pipes on the upper rear of the engine. These joined into a single pipe that passed into the right-hand sponson to the top of the radiator. This diagram and photo show the relevant holes in the wall between the engine and radiator compartments.
From the bottom of the right-hand radiator a pipe took water through the engine compartment, behind the engine, and upwards to the top of the left-hand radiator. Cool water returned to the lower rear left of the engine  .
These radiators are from the Bovington vehicle, in their original paint. The right-side radiator is painted black; the left-side one has the standard interior blue-grey colour. This may have been deliberately done to distinguish one kind of radiator from another. The grilles at front and back seem to be bare steel, but they are of course very dirty.
Like all other significant bolts on the Tiger, these on the front of the radiator have small bent pieces of metal attached beside them. This is to prevent them working loose.(The latest version of this article)