Chinese Alloy Radiator, Pressure Cap

[PLTR6]

I know, I'm inviting ridicule and head shaking, but in an attempt to identify the source of my overheating problems I bought an incredibly cheap rad off ebay for my 1970 TR6.

This was after many flushing sessions of block and radiator, retiming etc, new pressure caps and running without a thermostat but still seeing it running hot. The old rad is leak free and water runs happily through it when off the car so it may be fine, and I was pretty shocked by the price of a recore or a new rad, so before I go down that route I want to make sure the old rad really is the problem.

Hence the chinese rad, which arrived quickly and well packaged and looks ok TBH.  The bottom pipe is welded too high and only just fits under the cross member, but it went on eventually.  But I do have a problem.  It arrived with a chunky and seemingly well made pressure cap, which is rated at 19 PSI !.  This is way higher than the original 7 and then 13 PSI that Triumph specify.  I've been back to the supplier, who are responsive but haven't a clue about old cars, and the best they can supply is 1.1 bar or 16 PSI.    Of course it is a different (much deeper) fit to the original rad caps.  I can't seem to find an equivalent cap rated at a reasonable pressure. So my question is, does anyone know a source of suitable rad caps rated at 0.9 Bar or 13 PSI?   

Many Thanks

[billie]

I used a 13lb long reach radiator cap
bought off eBay, haven’t had any problems so far with this cap.