With regard to the original question , there have been numerous different engines put into Series Ones over the years most of which would probably not be very viable these days . First decision to be made is , do you want to keep it a diesel or are you open to change to a petrol ? How long do you think you will keep the vehicle ? Are you concerned about any future restrictions that might be put onto owners of diesel vehicles ? If so then petrol might be the way to go .
With regard to possible diesel options other than keeping what you have got , here are a few that I am aware of that have been done, 200DI( turbo removed)or TDI, 300TDI, 2.25 or 2.5 NA , Perkins , Peugeot or Daihatsu . There are probably loads more that I don’t know about . I considered quite seriously converting my 107” to a 200TDI for some time but decided not to in the end and had a 2.25 petrol installed instead ( more on that later) . The biggest drawback to diesels , especially the 200 And 300 TDIs , is the amount of noise they make when driving . You would need some serious sound deadening and ear defenders if you wanted to drive all the way to Scotland with one of those engines installed . There are people who do it , namely the boys in Team Faff (watch their YouTube videos very entertaining) and Dale Radford , but they are young and slightly deranged so probably shouldn’t be used as good examples . The plus side of diesels , of course, are their perceived fuel economy .
If you go the petrol route there are also a number of options , mostly of Rover origin . I wouldn’t bother with the 2l petrol as there would be minimal advantage in performance . You would need very deep pockets if you were to install a V8 or Ford V6 (very 1980s) and want to drive it to Scotland . I believe someone has installed a Rover K Series (2ltr?) engine but am unable to give any more information on that .
If it were mine I would go for either a 2.25 0r 2.5 l petrol breathed on engine with an Automotive Components remanufacturing(ACR) kit . I have such an engine in my 107” and it certainly makes it more useable and able to keep up with modern traffic . I have even over taken a Range Rover with it ! These are fairly common conversions with minimal amount of work required for the conversion . The main issue , if you are retaining the Series One gearbox , is getting the right bell housing . Don’t ask me which one is required as I am not that clued up . I have a reconditioned 2a gearbox in mine so there wasn’t an issue there .
Original 2l Diesel engines are pretty rare now , and whilst not being particularly desirable to most Series One owners you shouldn’t have too much trouble getting rid of it , should you chose to . The money you could get for it would help towards the conversion . However, if you have the space I would be inclined to keep it .
As for where to get the work done , I would suggest finding a specialist Land Rover Garage as undertaking such work would be second nature to them . I have it in mind that there are a few in your area but I would be prepared to travel to find someone you can trust . Check out the Land Rover magazines (in particular Classic Land Rover) for ideas .
If you haven’t already done so , you could try looking here
https://www.lrsoc.com/forum/index.php . There is a vast amount of knowledge there about Series Ones, but be prepared to be frowned on for wanting to change the engine by some purists . Just ignore them as you need a useable motor not a museum piece .
Hope this has helped . I am by no stretch of the imagination an expert but I have picked up one or two things over the last 30 plus years of Series One ownership . Of course , I haven’t learnt the most important lesson . Don’t own one !
I need a lie down for a rest now !
Good luck .
