Many thanks for responses and they are all useful to try and play with. It appears opening one side case and putting a fan on medium speed seems to do the trick (I should try low speed) and am running at 72C and 76C now.

I was hoping for a solution where I can keep everything enclosed. The Lian Li case has a fan at the back and what appears to be a front cooling kit in the front at that the bottom but not other fans embedded into the case. The 4x 5.25 bays in the front are not used.

I was wondering if something like another a front cooling kit can be placed in the 4 bays at the top of the front of the case (however lian li have discontinued this kit?) What additional fans could I put in and where?