Well let me start out with a little background on myself since this is my first post. Im 31 and have been a die hard BMW enthusiast my entire life. I currently own 4 BMW M3's and track them heavily. I do all my own work, engine rebuilds, etc and am also just finishing school for Chemical Engineering. Now i don't know how harsh you guys are on the new blood but i can say with absolute certainty that you have discussed this many times. so here it goes:

Ive been obsessed with discos for quite some time but have always heard about the problematic nature of them. The main thing I'm concerned with is the cylinder liner issue.

You can do all the research on the internet in the world but once you hear it from the true enthusiasts (which seem to be on this forum) is when you can take it for an absolute truth.

My concerns are as follows:
Will this definitely happen?
Is keeping the engine COOL a huge factor?
What is the MAIN factor this happens? Poor manufacturing?
Are the Disco 1 engines any better?

I appreciate any and all help. Thanks fellas!

 

Welcome aboard. Sure others will chime in but I think liners are more related to the year. Maybe 2003 if I recall, 4.6 motor and specific VIN range. I have a 2002 Disco II 4.0 with 165k and liners are not a problem.

Head gaskets on the other hand...

 

in the old days....when buick first started making the blocks...the liners were a rough cast piece and the aluminum block was poured around them..then they were bored to spec....the rough texture on the outside of iron liners kept them in place.......by the time Rover started buying the blocks from GM , the beancounters got involved and opted for smooth pressed in liners....to save time.....and cause countless ***-ache later.....these engins do run alittle on the hot side and sometimes hot enough to expand the block just enough for a sleeve to move down and then all hell breaks loose.
there have been several posts about "pinning the liners" and a couple different methods used.....not a bad Idea if you have the time and talent.......I had a liner slip on my1998 D1...."cylinder 7 missfire" code......it miss fired all right.....broke the top off the piston...soooooooo>>>> keep it cool, and pin them for good measure if you have the chance

 

I will start with the manufacturing process and go from there.
The Rover V8, is based on the early 1960 all aluminum v8 engine. Land Rover bored the aluminum, heated them up and stuck the room temp liners and them milled the deck.
They should have been pressed in after the cylinder cooled(liners have a tendency to get pushed out during the cooling process), but the did not.
All the engines were manufactured this way from the 3.5-4.6. The later engines were cast with thicker aluminum around the jugs and they went to 4 bolt mains(cross drilled).
The problems that they have are mostly heat related. Engines would loose their coolant(hose breaks, water pump gives out, etc, and they would reach damaging temps real fast.
The liners would move up and down and the aluminum around the jugs would crack allowing coolant into the combustion chamber.
They are designed to run in the 190-205 degree range, for emissions.
Renowned Rover V8 engine builders say, for maximum hp and minimum engine damaging heat, they keep theirs between 167-174 degrees with very few heat related problems.
After a few overheat episodes, the head gaskets usually have to be replaced.
In my opinion, too many shortcuts, or money saving decisions were made and customers have been paying the price for a couple of decades.
Their cooling system is designed more for passenger comfort, and the engines have suffered.
Many members have experimented with changes to the cooling system. Lower temp thermostats that came on the diesel, inline thermostat modifications, electric fans.
Some say leave them alone and just make sure everything is working as designed.
That is fine if you can live with head gaskets every 50-100k miles, I don't buy it personally.
If you want the engine to last and be dependable, do head gaskets using the MLS (Felpro) head gaskets, ARP studs and keep your temps below 200 degrees. If you have liner issues, get the top hat liners installed.
I recommend you to get a google account, and go to google books, and preview the book "How to build a Rover V8 for Road and Track" The first chapter is on the engine block and manufacturing process and it is free to preview that chapter.
Welcome aboard and plan on doing a lot of reading. I have only had a LR for 1 year, but have built engines for over 40 years. They are really simple and easy to work on.

 

will this happen? sooner or later.
is keeping the engine cool a big factor? yes
what is the main factor? poor manufacturing
are D1 engine better? there is a good chance

because the fanged liner is install proud of the block,
then machined level with the deck the head help to keep the liner from moving

 

I have owned 6 Discos (largely rescue, repair, and resell), daughter daily driver and mine. Year ranges 99-03. Have had 1 03 with the supposed slipped liner ticking - put a 160 degree inline thermostat in it and it went away. Daughters 00 has 200k on it and runs like a top - had to do head gaskets after she overheated it but othewise runs great with very good oil pressure. Degreed Mechanical engineer with 30 yrs experience and lifelong gearhead (although my taste runs more to muscle cars, but do have a 99 E46 my son drives and loves).

In my opinion:

1. Slipped liner or cracked liner or head gasket failure will likely never happen if you don't overheat it.
2. Poor quality plastics are the primary reason for overheating. In the 6 we have had I have seen cracked radiator tanks, overflow bottles, leaking throttle body gaskets, stuck thermostats, cracked radiator hose tees, exploding fans, and broken hard plastic coolant lines. Best advice is put in a aftermarket temp gauge, install inline thermostat mod, and get in the habit of looking under the front every time you get in it to see if it is leaking coolant. As long as it has coolant in it they usually don't overheat.
3. I think there is some validity to the later blocks having looser tolerances resulting in more frequent issues - maybe find one with a blown engine and get a early RR 4.6 (95-97)?