Standard Rad on the R26, running360bhp, has no problems. I have come across several with overheating, and the rad fan was the wrong way around. Some remove the rubber strip from the scuttle panel. I used some paper strip, and it blew back towards the windscreen, showing air was moving in the right direction, as I had been told, it was a low pressure, and a waste of time doing. I also Velcro the number plate, and drilled extra holes there.