The Raceline cast alloy water rail is designed to simplify the cooling system and plumbing of the Ford Zetec engine when installed in-line. Because of its innate simplicity, it can enhance reliability as much as it enhances the underbonnet appearance of any such vehicle. The Raceline water rail is designed to closely follow the contours of the Ford cam cover and to look as nearly as possible like a 'factory' component, which is reflected in the high quality of the casting.
Although it may be possible to retain the standard Ford Mondeo thermostat mounted at the rear of the engine, suitably plumbed in, the Raceline water rail allows what is undeniably a far neater installation. It moves the thermostat housing to a position near the front of the engine, making the plumbing simpler, neater, and in theory more reliable too, as the fewer the number of joints in the system (count the number of jubilee clips!) the less the potential for failure.
Raceline use and recommend the 1800 Zetec water pump for all its engine conversions, and when the Raceline water rail is used in conjunction with a 1800 water pump the system operates as follows: the water pump draws coolant from the radiator and pumps it into the water jacket, and as the coolant absorbs heat from the engine it flows back and up into the Raceline water rail at the rear of the cylinder head, where the Ford thermostat housing was previously mounted. Coolant then passes forward along the water rail towards the thermostat housing. From there, it returns to the radiator, provided the thermostat is open. During the warm-up phase a small by-pass hole in the thermostat allows some water flow, so preventing local overheating.
The Raceline water rail is designed for use without a header tank, although it is possible to incorporate one in the cooling system if preferred. We prefer the inherent simplicity and efficiency of running the cooling system without a header tank, the only disadvantage being that the coolant level can not be monitored at a glance as it can with the semi-transparent header tank common to most such systems. Therefore the cooling system must be checked and topped up regularly, and as the coolant heats up and expands the excess will be expelled, allowing the system to find its own level.