Right i'm just starting to look at plumbing in the cooling system for my '05 r1 engined stm.
The rad i am using was as supplied by stm, not sure what it is, definitely not the micra or polo rad tho.
I haven't purchased a header tank yet and was wondering what the best choice would be, off any bike/car? or purchase an aftermarket aluminium one?
How many connections should there be on it?
cheers

I am going with a rover one with a float switch as I have a rear engine and I am fitting a dash warning.
The best setup is an expansion tank at the highest point in the system with two pipes and a pressure cap.
The larger bottom pipe in the tank (16mm approx) goes to a tee in the return from the rad to the engine (bottom hose) and the smaller (8mm) top hose in the tank picks up as many points as you like from the top of the engine or rad.
I am going to pick up the small thermostat hose plus a small bleed pipe from the top of my rad.
Basically you will get a small amount of circulating water through the expansion tank (even when the stat is closed) which will level the water system and remove any air.

just done a bit more searching on this, so think i'm going to go to the scrappers to try find something reasonably suitable...

What model rover was yours from nitram?

Anyone else recommend a suitable car to take one from..?

My one was from one of later MG's.
I bought mine brand new from rover as I am buying all new for a new reg number.
It was fitted to late rovers because the temp gauge is located in a position on the engine that actually reads normal temps if the water level drops. This means lots of drivers continuing to drive and causing headgasket failure.
A simple dash warning would hopefully make them top the system up.

Mine is as Nitram's, only I'm using a Polo "globe " type bottle and my large hose goes into the top hose. Bottom hose is more normal but it doesn't make a lot of difference (just means that you're getting some slight cooling with the 'stat closed as the bypass/bleed hose water is going through the rad' and it was an easier layout.

adrian