With a proper header tank installed, there will be a good reserve of gravity fed coolant, and with a low level detector an early warning is issued well in advance of the coolant becoming dangerously low. This prevents engine failure by enabling the driver to stop and investigate the problem before the damage is done.

Stag Header Tank; The Cooling System Upgrade.

The header tank pictured here is a custom designed, lightweight aluminium alloy tank, and being a horizontal cube fits neatly into the spare space on the front left side of the Stag engine bay. The tank supplies coolant to the engine via a large diameter hose plumbed into the intake of the water pump. Coolant circulates through the tank, so any air in the system is returned to the tank via a restricted small bore hose from the top of the radiator.  Note: the tank has been redesigned and improved to make it also possible to fit with a relocated alternator.  To achieve this the lower tank hose position is moved to the end of the tank and is now an AN10 type screw fitting for much more flexibility of installation. A 90 deg hose fitting is included in the fitting kit. The level sensor has also been baffled to improve function.

Fitting Kit :

The optional fitting kit contains hoses, clips, hose adapters, and all other parts necessary to fit the header tank system to any standard Triumph Stag.  Also included are clear, illustrated instructions which should enable most DIY mechanics to fit the kit in 1 hour.  To view the feedback on this product, please click the 'Testimonials' tab at the top.

Which do I order, Mark1 cooling or Mark 2 cooling? 

a) Mk2: If your radiator has pressure cap on the expansion bottle not the radiator it is probably the usual Mk2 type and the standard Mk2 kit should be suitable. However, if you have a non-standard radiator where  the filler boss of your Mk2 radiator is too high then add the Mk1 option.

b) Mk1: Alternatively if you have the very early system, with the (13lb) pressure cap on the radiator, you will need the Mk1 option

c) If you are still not sure, order the Mk1 option as this will fit any standard system.

Other information: non standard water pump: If you have fitted a non standard external water pump it is advisable to seek advice from your supplier about installation of a header tank. 

Summary of Features

Here is a header tank kit designed especially for the stag. This can be easily fitted, and will provide crucial cooling system protection for your stag engine. The main design requirements were as follows:

• To provide a safe additional reserve of gravity fed coolant

• Incorporate a "Low-Coolant" early warning system

• Prevent unnecessary engine failure due to coolant loss

• Circulate coolant to purge it of trapped air

• Tank has an attractive alloy finish; paint or polish yourself

• Fits any standard UK Stag (may also fit others)

• Retains good access to spark plugs and other components

• No modifications necessary to radiator

• Complete with all parts and instructions  

Gravity is King!

      Made in England using local engineering resources.

​23/11/21 currently 2-3 weeks delivery