It's a 16 valve twin cam head designed and fitted to an A series engine. Years ago when I played with Minis I used to dream about fitting such a thing, but it was always way out of my budget (along with 5 speed boxes).
KAD are the company that made them, don't know if they're still going now or if s/h is the only source.
They might make use of the evil cursed rubber band, but I remember reading about them when they were launched - They add a fair chunk of go to an A series lump!
I thought they might have got cheaper over time, but found a US site with them listed for around 7.5k dollars, which is what, about 4k UK pounds I think. If I had that sort of money for an oily engine bit I'd be a far happier man!
It looks like the KAD boys (or girls ) used a motorcycle head as well, by looking at the carb setup
Onne van der S. MMOCno 60520 Moderator
2dr 1971 White DAF 55 (with hopefully a 1600cc engine soon)
2dr 1973 Bergina (DAF 44)
2dr Estate 1975 DAF 46 in red
2dr saloon 1972 DAF 44 in Mimosa
I can't remember the development story, but I wouldn't be surprised if they used a motorbike head as inspiration. Don't be fooled by the carbs though, I have a feeling everything from one bike carb per cylinder through to fully mapped efi was used!