I just got a heating core from a scrap yard. The owner didn't seem to know what I was talking about and said just go have a look around. In a shack there were loads of car parts, and on a shelf was a gleaming radiator. £10
No idea what it's history is, or even if it could have been a transmission or oil cooler... probably not though. I think it's made from brass... well the in/outlet pipes are made of ayellow metal.
Picture here
As you can see it's huge. Those fans are 80mm. It fits perfectly in my case too.
My only problem now is getting pipes to fix to it. My pump is 10mm, my cpu waterblock is 8mm, this thing's 15mm...
I have noticed the lack of decent watercooling shops in the UK, and the huge stack of them in US. What's going on?