Land rover 4.6 vs Range Rover 4.6

[DNTL740]

Hello all, I have a 01 discovery in which the 4 liter is slowly falling apart, the heads are leaking like a sieve, it has a bad knock at start up which quiets down and never really goes away.

So I have been doing my research on what I can do to build a bulletproof engine. Ive spoken to several reputable machine shops trying to get a feel for how much it would cost to build a block with top hat liners and all the other goodies they do to these blocks. Going rate is anywhere from $1600 to $2300, just for the machine work alone.

So I started looking for a core engine that will donate a block to do the work on, that is when I spoke to somebody and they told me that they were doing engine swaps on the later Discoveries ( 99-04) with 4.6 liter engines from the 99-02 Range Rovers. He informed me that theses engines were better built than the Discovery engines, and were less likely to develop the problems that the Discovery engine will develop.

Range rover engines go for about $2200, to $3000, and from what he told me the engines he sells are ready to bolt on. (this guy is a very reputable source of info so I trust him when he says they are ready to bolt on).

The question is: Could it be true that these Range Rover engines are any different than the land rover ones? I have checked a few Range Rover forums, and none of them really have much on slipped liners, unlike the Land rover forums, where thats all you hear.

Thanks, Cristian Larrondo

 

[UnfrozenCaveman]

Hmmm....you're in Riverside....

On a forum sponsored by Inland Rovers....

It's a stretch, but have you phoned / stopped in to visit with them for an opinion?

My understanding is - and I'm just the accountant here folks - that it's pretty tough to definitively diagnose a slipped liner without having the thing apart.

I cannot see any reason to expect a used/drop in engine to last any longer than the one that is already in your vehicle.

And <-sticks neck out-> I have a hard time believing that the RR engines received any more careful assembly than the Disco engines.

The 3.9 in the old Disco is still chugging along and the 4.0 in the 90 is just fine....knock on wood...but if / when it starts drinking / leaking more that I'm comfortable with it will get a full rebuild with "top hat" or pinned liners.

....pssttt...and I'm going to guess that the "knock" is cam related...shhhh

 

[Chazz Layne]

...on the later Discoveries ( 99-04) with 4.6 liter engines from the 99-02 Range Rovers. He informed me that theses engines were better built than the Discovery engines, and were less likely to develop the problems that the Discovery engine will develop.

...

The question is: Could it be true that these Range Rover engines are any different than the land rover ones? I have checked a few Range Rover forums, and none of them really have much on slipped liners, unlike the Land rover forums, where thats all you hear.

False.

The Land Rover 4.0 and 4.6 are essentially the same engine (the 4.6 is just bored out larger), the Rover V8 that began life years ago as a Buick design. Some of the electronics surrounding the engine vary from year to year and model to model (Range vs. Disco), but the hardware is the same.

 

[evilfij]

There is a theory that toward the end of the 4.6 production run the castings got bad. Personally, I believe that the DII is POS and runs too hot from the factory.

Ron

 

[DNTL740]

There is a theory that toward the end of the 4.6 production run the castings got bad. Personally, I believe that the DII is POS and runs too hot from the factory.

Ron

thats what I have always heard, so if you look at it from that point, the Range Rover 4.6 would be a better engine.

Chazz, I believe the engine was stroked not bored.

Cristian

 

[evilfij]

True, stroked. The block between a 4.0 and a 4.6 is the same. The only difference that i know that matters between a bosch and a GEMs block is the mounting plate for the crank sensor. You can cut the weld and swap them around though. Back in the day when bosch 4.0 blocks were $800 dealer cost, I sold a lot of them as retrofit for all rovers from 87 RRCs on up.

 

[Chazz Layne]

There is a theory that toward the end of the 4.6 production run the castings got bad. Personally, I believe that the DII is POS and runs too hot from the factory.

Ron

Both of mine have been steady, be it 40 degrees outside or 120... never had a problem. The only thing I can think of to watch out for is the 2003 builds that had the holes in the wrong spot for mounting the oil pump (that was a big mess for LR, fix required engine replacement).



To answer the other original question, the key to keeping these engines running good and running long is timely and thorough maintenance. Afterall, no matter how well it is built it is still British, not a Honda...

 

[spikemd]

Good info on disco engines

I think I agree that the Disco engines are more prone to slipping based on these forums. I don't know if that is a selection bias because there are more Disco owners on these forums or if there are simply more Discos on the road.

Here is a link to someone who has been trying to figure this out. Very informative.
http://www.rangerovers.net/forum/viewtopic.php?f=3&t=38535&start=0&hilit=slipped

and his blog with more info. He actually cut a Disco engine in half!
http://robisonservice.blogspot.com/2010/04/last-word-on-land-rover-liner-failures.html

 

[dcwhybrew]

Just for clarification, there isnt any difference between an Range Rover engine and a Land Rover (or Disco as also stated earlier). They are all the same engines. The only differences were the engine management systems, either Bosch or GEMS. The DIIs and late 99-02 RRs used Bosch. On the DII, one of the things to look out for is whether you have the Secondary Air Injection or not?

roverland.com has good prices on remanufactured engines.

 

[DNTL740]

Thanks for all the info. So I guess there is no difference between the RR 4.6, and the LR 4.6. I was hoping the answer would have been that the RR engine was better built, but I guess not.

Cristian

 

[dcwhybrew]

Thanks for all the info. So I guess there is no difference between the RR 4.6, and the LR 4.6. I was hoping the answer would have been that the RR engine was better built, but I guess not.

Cristian

Nope, sorry...they are the exact same engine.

 

[rovertech]

Thanks for all the info. So I guess there is no difference between the RR 4.6, and the LR 4.6. I was hoping the answer would have been that the RR engine was better built, but I guess not.

Cristian

The 4.6's are the same, but for clarification a 4.0 is NOT the same block as a 4.6. While outside dimensions and cylinder bore are the same thats where it ends. The 4.6 has more material between the cylinder liner and the water jackets making it more resistant to cracking. There are two grades of 4.0L and three of 4.6L the strongest grade 4.0 won't pass inspection for a 4.6L build unless it at it's thickest. Most 4.0L engines I have seen are the weaker grade.

I personally don't believe LR build quality was as good on the late 4.6 as the early so from that standpoint I think you are better looking for a RR engine. I have 2 engines at a machine shop now both of which spun cam bearings. Both had regular servicing and were not abused. The factory machine work was terrible.

Regarding D2 being POS and running too hot the P38 started that in 1995 with the thermostat change. I agree they are running on the edge which is why they tend to crack following an overheat, but that isn't new with the D2.

 

[Douglas S.]

We had a similar problem with the 5.0 in our Rangie, slipped a liner and blew out a piston. Engine is currently being fully top hat sleeved and rebuilt with all new pistons, etc.