Joaquin,
I certainly respect your opinion but there may have perhaps been something wrong with the 4BT you drove? Even bone stock I found myself flying up the 8000 ft 15 minute long passes in 5th gear only occasionally having to downshift to 4th and never less than 65mph. This is also in a heavy vehicle with 35" tires... I also towed vehicles, etc etc... They also have almost a wall of torque at idle, they will literally idle over and through anything possibly including your brakes. I would use first low to get down to the equivalent of vehicles with 100:1 low ranges, down to 300-400 rpms with brakes to slow down the idle, and it would not stall, just keep on crawling... On the highway in stock configuration feels like a V8 on the highway I would say... I had no issues going 75-80 easily, even when fully loaded, and always got over 20 mpg (about 22 average when driving 70-75mph plus), and if geared right (fast) with 33" all terrains you can get as high as 27 mpg on average...
The big issues are again fitment because the engine and its large sump are deep (not necessarily tall), and the noise of course. I found no real complaints about the vibration personally and found this is mostly overrated. 4cyls are rougher but I used rubber mounts the first time and it was fine (only noticeable if you wanted to notice, and at idle only). Even in town or in traffic vibration was never bad)... But this time I'm using the OEM Cummins liquid filled mounts and they will really let it shake around without feeling it. But mostly because I have them, not because they are needed... Then on top of that all of the cheap or free power you can get out of them, turn up the pump, and/or buy a cheap used turbo from a Dodge guy who is upgrading (there is a restrictive stock Dodge turbo from about 2001-2004 that is the perfect fit for the 4BT, usually had for $200-300 at most).
Would I recommend it for a Rover? Possibly but probably not unless I knew the engine would fit. But they do fit OK in Land Cruisers. It is a little tight in the front end with 40 and 55 stock width axles. Best is to upgrade to 60 series front axle for a number of reasons and you get a little more breathing room. In a Range Rover classic that would be cool. The NV4500 doesn't have a good adapter to the LT230 though, you will need to run a dual offset Land Cruiser t-case. An Orion at 3:1 would be awesome.
There is a thread on my forum,
www.4btswaps.com, with info about fitment into Defender Rovers... Really my only complaint is the wide shifting, even with the later tighter pattern of the NV4500, combined with the 4BT and its low power band (factory governed at about 2300-2500rpms), made for odd shifting. It is basically a 3 speed with an underdrive and over drive. I found myself starting in 2nd unless starting up hill...
Hope it helps, Andre
Once it comes there will be all kinds of fun conversion options. It'll be here soon.
