No No nuthing wrong with the engine just wanna get some extra horsies under the hood, I have never modded any of my cars engine wise and having solf my XJ at a good price I have some monies left to mess about after the suspension mods.

I have also been told to just change the short block, Lemme guess short block includes all the other stuff in it as well right ? like pistons conrods cams etc etc right ?.And the heads and other stuff is bolt right on the 4.6 block right.

Any idea how many horsies will I gain will the block swap

Cool

 

Well the 4.0 has 182 horse power while the 4.6 has 188 horse power.
If you used the same block you would need a new crank, con rods and cam.
The 4.6 is a 4.0 with a longer stroke.

 

But the range rover 4.6 GEMS are rated at 225HP or something ?

 

Well that is also with the RR ECU.
Here in the States they have to tune everything down because we wimpy Yanks cannot handle that much power. Just like we cant get diesles, or manual transmissions, or anything that goes fast, or just plain old anything cool.
We just are not allowed.
Here is a example, the UK DI is rated at 7,000lbs towing capacity, the US DI is rated at 5,000lbs. Same truck, different ratings.
So what you have in the Middle East my very well have a different HP rating.

 

2004 Land Rover Disco II' with 4.6L V8
217 Hp @ 4750 rpm and 300 ftlbs Tq @ 2600rpm

 

The Range Rover motor with a distributer is a 4.2L V8
you will have more homework to do.

 

Consider rebuilding your engine, cam and modified head work with large chambers, throw on a set of headers and a better exhaust system and your pick up a good 45 plus horse power.

 

All sounds like a lot of work and money when your current engine is still good.

 

Thats why you start getting parts now while you still have a
good motor so you can take your time and not have a cash
outlay all at once,,,pro-active not reactive.

 

OMG, I don't know where to begin with this one.

Yes, you can put a distributor on a 4.6. it will require a cam that supports the distributor drive, and a front cover with provision for the distributor, but there is no reason it cannot be done.

GEMS ECUs can be programmed pretty easily to accommodate the 4.6 versus the 4.0.

The 4.6 is NOT longer than the 4.0. GEMS front covers can be interchanged as long as one pays attention to the oil pick up configuration.

Lastly, when discussing Gulf-Spec vehicles, things we see in the US are not as they might appear over there. They had distributor engines with Lucas EMS as late as 1999, no cats and IIRC, no oxygen sensors.