There is no 'magic' cam for rallying.
Whichever cam you fit there will be times when you wish you had more power, or more torque, or the power at a different rpm figure.
On a long tarmac straight out of a square corner, you might wish you had a 296, but on a twisty and wet tight little road with some mud or gravel you might pray for a 266 or equivalent.
For racing it is, of course, entirely different as a couple of extra bhp will improve the lap time by a tenth of a second or better. That is important. In rallying it is entirely different. For tarmac stages I think a 286 is hard to beat, but for gravel/ice/mud a 276 or even a 266 is better.
Yes, there are other cams all of which are claimed, by those selling them of course, to be a huge improvement over the existing available range, but after over 60 years of cam design further improvements for the A-series is probably just 'turd polishing'.
I was involved in a group test for Mini Mag a few years ago where 9 rally Minis were all tested. Each of us drove several cars. Fastest in a straight line was a 1293 'S' with a 649 cam, 40 DCOE Weber and an LSD. However, it was very slow on the twisty handling test where my car with twin H4's and a 286 was fastest on the dry tarmac. On a little autotest type course there a Mini with a 510 'S' cam came out best.
I always stick with Kent cams because their range is wide and well-established for competition.
I did a rally in my 1310 cc 'S' with its 286 cam and it was snowy. The whole thing was horrendous. I couldn't get the car to go as it needed over 3000 rpm to get it moving and that just spun the wheels. How I wished for a standard 'S' cam at that time.
