I've heard of people using header tanks such as these...

http://cgi.ebay.co.uk/Rover-coupe-turbo-header-tank-and-coolant-rail-VGC_W0QQitemZ270018135077QQihZ017QQcategoryZ10414QQrdZ1QQcmdZViewItem

I'm using it with an R1 and hence need one that has a pressure relief cap and two inlets. One high and one low if possible. Any ideas?

Lastly do the caps on the header tanks on something like a Rover or a Passat (the plastic type things) have a pressure relief built into them?

Ta,

Chris.

[Edited on 20-8-06 by Winston Todge]

Why not put a 'T' or 'Y' piece into one of the pipes?
I have put a 'Y' in my header tank to take a bleed off the engine block and one off my rad. The larger pipe goes to the lowest point on the rad return pipe.
My engine is a 1.4 K series.
I bought my unions from thinkautomotive on Friday and they arrived Saturday.
I made my own ali catch tank and I use a standard rad cap, but the plastic one you mentioned has a pressure relief cap.
Good luck

[Edited on 20/8/2006 by nitram38]

I used the same item in the link, although came off a rover 200. £5 from the scrappies. (plus the mandatory pocket full of stainless clips)

Cheers Nige