Always good to see this kinda thread pop-up and while discussed to death, there are always new options and thoughts on the matter.
I think Out of the box solutions, the R1 solution would easily fit, provide great power and of course sound awesome. Downsides being the frame etc alone costs £3.5k before you even have an engine. Add that it would only have an electric reverse if any - but then you do get 6 forward gears and a very fun pullup / pushdown gear change!
This is a friends installation;
Looks perfectly sized in a mini engine bay, still 1000cc too.
Most other solutions will require headlight modification,
Scholar Racing have a nice K series install in a Mk3 and utilising Porsche 928 pop up lights;
Which...works, but isn't very attractive. Personally I'd just push the lights forward, change the headlights to something half-height and bring the bonnet down to match ( I will do a photoshop later to explain a bit better!)
I've stated before I'd quite like to do a Honda conversion, mostly because the cars are quite readily available - as is parts and they provide good power for size / CC.
The favourite among the
mini 16valvers are the B series engines 1.6/1.8L ~150bhp, these are a bit big in the OHV department[/url] and would need headlights moving, bonnet bulging and headlight modifications to fit.
I believe a
D series engine, while a bit rarer would be a better fit, 1.5L provides 90-100bhp, unfortuantely EU never got the 128bhp 1.6L VTEC model. There are the 1.6L models that put out 100-130bhp and are found not only in Hondas but some old Rover GSI's (216/416).
Well that's my food for thought!
These are a lot less bulky to the rocker cover, see the right hand side (passenger side) in these photos, compared to the B engine above they don't even reach the minis inner-arches, which would possibly mean that the lights may not need to be modified;