You can't use the 3.9 pistons.

 

I'd save up for an LS swap.
My experience with a "built" 4.6l - ported and polished heads, Crower cam, Tornado chip in the ECU, was that I was disappointed.
So then I bought a supercharged 3.9l and promptly blew it up. Had it rebuilt by Rob Dassler even though he wouldn't warranty it because of the supercharger. It was disappointing.
Next I bought a Megasquirt setup including distributorless ignition and a computer programmable ecu to add to the supercharger. Pain in the ass trying to program it and then I had an engine fire and burnt up the wiring, totalling the Range Rover.
So, save your money and do an LS or realize that the 4.6l is not a huge jump up from the 3.9l and will still probably disappoint you after you have spent a lot of money.
Also, the 14cux isn't a distributor it is an ECU (engine controller)

 

Went through almost the same exact process. A built 4.6 is not impressive, it's just a marginal upgrade over a 3.9. My shop is just about done with an LS swap. I pick up the truck next week and will post my thoughts. I couldn't tell you much now anyway as the computer has a rev limiter on the motor for the first 4 hours anyway and we aren't through that part yet.

 

I'd have to agree with the above.

I drove a stock '04 D2 with a 4.6 for 2 years and honestly didn't feel like it had any more power than my 3.9 trail truck.

If you're doing the 4.6 on the cheap, then by all means go for it.
I wouldnt put a lot of time and $$ in it and expect much back.

All reports on the LS are win-win.
Be the first to put one in a ragged out Disco.


.

 

I know the 14CUX is an engine management system.
Most LS swaps are coming in at what, $5-7000 at least??
I looking more in the sub-$2000 range. I know the 4.6 won't push me into my seat. My 96 D1 is totally stock and it still pulls pretty good on the highway. Any upgrade over that and I'd be happy.
I won't touch a supercharged Rover engine, I've read up enough to know that.

If I can get my block/4.6 parts for around $1000 I can rebuild the rest for about another $1000. I've already got the headers, ECU's, MSD ignition parts, and a whole slew of other Rover parts.

 

14 CUX is a FUEL management system. As such it manages to use as much as it can!!!

 

Why not just pull a 4.6 out of a wrecked Disco 2?

 

Yeah that's an option, too. Will a Bosch 4.6 work?

Went through almost the same exact process. A built 4.6 is not impressive, it's just a marginal upgrade over a 3.9. My shop is just about done with an LS swap. I pick up the truck next week and will post my thoughts. I couldn't tell you much now anyway as the computer has a rev limiter on the motor for the first 4 hours anyway and we aren't through that part yet.

I'm on a Disco budget, not a Defender budget.
What's your out the door price on that swap?

 

4.6 will work but not Bosch with different electronics etc. Can you change the front end back to 14CUX? Word I hear is that the D2 blocks are falling by the way side in ever increasing numbers.

 

Odd. I'll chime in an say that my built 4.6 had noticeably more usable power on my previous D1; while in the current 4.0 5 speed I can control the application better there is a noticeable difference in 'seat of the pants' feel-at least there was in the various trucks that I've owned.

I do wonder what people are looking for in the way of power output of course, if we're expected it to be a supercharged Rangie feel it won't get you there.

I'll go ahead an also be contrary and say that the LS swap has seemed like a great internet idea for what, a decade-but how many people have effectively executed it in a cheap and easily repeatable fashion?

I'd go 4.6l w/4.0 pistons and swap over the 14CUX & associated necessities and I think you'll be pleased enough with the return on investment, esp if you do the work yourself to mitigate cost.
r-
Ray

 

I'd go 4.6l w/4.0 pistons and swap over the 14CUX & associated necessities and I think you'll be pleased enough with the return on investment, esp if you do the work yourself to mitigate cost.
r-
Ray

That's where I'm headed I think. I do all my own work.

You should buy Tony's built 14CUX 4.6. I was going to but ended up just fixing what I have. You can't do it yourself for what he is asking. Shipping to you via fastenal will be about 2-250.

Got a link or full user name?

 

You should buy Tony's built 14CUX 4.6. I was going to but ended up just fixing what I have. You can't do it yourself for what he is asking. Shipping to you via fastenal will be about 2-250.

 

You should buy Tony's built 14CUX 4.6.

I was going to say the same thing...

 

Huh? I thought you wanted a distributor motor.

 

94 and 95 D1 are distributor, but with serpentine belts.

------ Follow up post added June 27th, 2016 01:25 PM ------

Yeah that's an option, too. Will a Bosch 4.6 work?

Since you aren't going to be using the crank sensor anyway, there isn't much difference between a Bosch block and a GEMS block. A d2 engine should work fine, after you swap the D1 stuff that is different over.

 

From a performance perspective you might consider re-gearing options. 411's made my NAS90 more civil compared to the 354/ZF stock combo.

 

Already done. I've got Ashcroft 4.12's with Ashcroft lockers front and rear. Final tire size should be between a 255/85 and true 35. I know it could be lower but it will be closer to stock gearing than my 235/85's on 3.54's.

 

Sharing a lightly edited dialogue with a friend and long term Rover owner just because his words convey context to the 4.0 piston discussion:

You can do the 4.0 pistons for just a bit more cost and it does make a difference. If you port and polish the heads to truly get the benefits you want to put a performance cam in it too. All of those should be reliable. I run a 4.6 with 4.0 pistons stock cam and heads. I have almost 50,000 miles on that set up I put it in the winter before Oakridge. Truly no worries but it does push oil due to the compression and it is leaking oil but don’t they all?

I did a stock 4.6 in ___ truck so she would not have the Premium gas worries

If you do the 4.6 with 4.0 pistons you MUST run good premium gas.

Opening the heads and adding the cam will add - if you did the 4.0 pistons heads and cam I can see you getting close to almost 245hp NO proof or Dyno to prove that estimate but a stock 4.6 should net you 220hp. I guess if you don’t mind the premium gas think of it this way. You will add around $1000 to the build and it will feel like going from a 195 hp 4.0 to a 220 hp 4.6 only you will be going from a 220 hp 4.6 to a 245 hp performance 4.6. It should be reliable and dependable with no worries. The GEMs fuel mixture can handle it without a CHIP but if you added the Mark Adams Chip to work on the timing and mixture (costly $1700) you might even gain another 10 – 15 hp. How much is enough? and how far do you want to go?

Keep in mind this was for a GEMs engine and I do wonder if the fuel management system there may be a little more forgiving but that's supposition on my part. The emphasis I added was to illustrate a real world long term (I consider 50k in a Rover long term) application.

Put another way if/when I start building a replacement for Coyote I'll likely find a 4.0 GEMS block (i.e. not the later year 4.6 blocks), put a 4.6 crank/rods in it with 4.0 pistons, port/polish myself and a mild cam. That's daydreaming of course. First I have to have little things like my household goods show up and such....

 

Good input Ray. Although I run 4.6 pistons I do have a stage 2 crower cam as well as Mark's chip (It's around $650... but on sale now thanks to Brexit), a setup which also requires premium gas. There is definitely a noticeable difference from my 3.9 which makes paying more for gas acceptable.

Sharing a lightly edited dialogue with a friend and long term Rover owner just because his words convey context to the 4.0 piston discussion:
Keep in mind this was for a GEMs engine and I do wonder if the fuel management system there may be a little more forgiving but that's supposition on my part. The emphasis I added was to illustrate a real world long term (I consider 50k in a Rover long term) application.

Put another way if/when I start building a replacement for Coyote I'll likely find a 4.0 GEMS block (i.e. not the later year 4.6 blocks), put a 4.6 crank/rods in it with 4.0 pistons, port/polish myself and a mild cam. That's daydreaming of course. First I have to have little things like my household goods show up and such....

 

So are the 4.6 benefits primarily in 0-60 or 70-90?

 

I've noticed a significant increase in pick up. I almost always start in second, even on incline. I can also (not that it is a good idea) cruise at 80.

 

94 ecu

If you project is complete any chance you want to part with an ECU? 94 NAS

------ Follow up post added October 1st, 2016 12:20 PM ------

Any chance you want to part with a spare 3.9 ECU for a 94 NAS?

 

If you project is complete any chance you want to part with an ECU? 94 NAS

------ Follow up post added October 1st, 2016 12:20 PM ------

Any chance you want to part with a spare 3.9 ECU for a 94 NAS?

If he doesn't want to I have one from my 1994 D90 from when it was converted to a diesel.

 

Sure I'll take it. Look for PM.

 

For what it's worth as far as "closure" on some topics here - I have Tony's 4.6 project motor in my garage now, finally on an engine stand. Shortblock is on the stand, I should say. Build up will commence any day now. However, will not be bale to comment on performanc ein a D1/D2 as it's going in a HCPU that I'm trying to keep as light as I can.

 

I had a 3.9 for years in my D90 and the replaced with the 4.6. Crower high torque cam, Pendy's refuelling chip, slightly overbored using RealSteel pistons. I had 60K on the 3.9 so not used up by any stretch and I did notice a difference between the two motors. I live in CO and the hills are everywhere and I went from sluggish on the hills of I70 by the tunnels to being able to keep up alright. Stock gearing. It is a good upgrade.

Now that I am towing an offroad trailer, however, I am looking for something a little more grunt/low end torque... Still deciding on what. Maybe a TD5, maybe a 2.8 Cummins, maybe an LS.... If it wasn't for the towing, I'd be perfectly satisfied with my 4.6