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ThreePointFive

4.0 GEMS engine swap

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Quagmire    20

I bought a second MS recently from DIYAutoTune in kit form for my Dads birthday- with shipping and tax I think it was around £180? Factor in a bit more for building up a loom too.

You could go fuel only for now on a dizzy setup to save the extra cost of coil packs, triggerwheel etc. It'd be like stock then but with the tweakability of MS.

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FridgeFreezer    369

I think the point has been made... but let's assume for now he's sticking with carbs.

So:

You can bolt carbs to *any* V8, the difficulty is the distributor drive / cam-nose / crank-nose, which restricts you to either swapping cams or pre-P38 engines (3.5, 3.9, 4.2).

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FridgeFreezer    369

Later V8's with cast sump yes - if you change the front cover you'll have to swap back to the steel sump. My 4.6 is the earlier type and that has a more normal steel sump, although it's still different to the 3.5/3.9/4.2 sump I don't know if they're compatible; it's deeper and has the drain plug in the bottom rather than the side, which I reckon is an improvement.

P38 dipstick is the bottom one, you can see how much deeper it is:

IMG_9284.JPG

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FridgeFreezer    369

I'd assume it's whenever they went over to the Thor type EFI with the "bunch of bananas" inlet manifold, but the parts book would tell you for sure.

Note I'm not 100% sure the steel sumps are interchangeable as I think the front end is different.

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Davewillb    3

Ref RPI from earlier in the thread...... I have spent money there in the past and won't be going back.

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Well the engine is coming out of my old chassis this coming week, what goes in to the new chassis is still a debate.

I can get hold of a complete (ancillaries, loom, ECU) 4.0 for not stupid money, I would look to MS if I can find a way to do it so that the total cost is less than £1k. If anyone knows of suppliers of parts for doing MS I'd really appreciate it. This is of course unless I have totally misunderstood, and the P38 lump will not function at all without the various other P38 bits even if it was swapped to MS - I admit I don't totally understand why it wouldn't work on EFI if the ECU is present. Maybe someone here could explain it?

Davedef90 is totally correct, I have done everything so far to a certain standard, and the engine should arguably be the pinnacle of the build. It is, after all, what makes a V8 90 what it is. Whatever I do have to be to the same standard.

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q-rover    0

The engine is a lump of dumb metal, it has no idea what is making it do what it does.

Getting the correct inputs to MS will not be a problem.

Getting it to run with the original LR ECU could be problematic, as on the P38, all ECU's

were tied into the BECM which is where the security features are.

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FridgeFreezer    369

How much is the 4.0, do you get a discount if you don't have the ECU as that's not required for MS?

Nige will sell you a "solder it yourself" kit of parts for not very much, the brackets for coil packs & VR sensors are very nice to have but you can make your own or re-use the P38 coils if you want.

Personally, having done the "mongrel" V8 thing, it's far nicer to put a complete lump in with all the correct bits - makes spares & plumbing so much nicer. The serpentine front end also makes belt-changes a 10-second job & swapping the alternator all of about 5 minutes.

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Thanks FF, I know it can be hard work explaining something like this to someone with nearly no subject knowledge. My thoughts were that keeping the engine as-is would keep things simpler, make selling easier and generally keep reliability rather than the mish-mash I would otherwise be resorting to.

I would have to buy the engine complete, but I am guessing a loom and ECU would sell separately should I want to.

The solder yourself kits being the £228ish one on his site?

I don't expect a run down of everything MS related, Nige's site is pretty much that anyway. I am guessing for a 4.0 I need fuel and spark though as (I think...?) that's what EFI does?

The only thing that concerns me is the tunability of MS - I need to ensure the output doesn't exceed standard for insurance reasons.

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FridgeFreezer    369
The only thing that concerns me is the tunability of MS - I need to ensure the output doesn't exceed standard for insurance reasons.

Um, you want to tune a 4.0 to give the same ~98bhp as a factory carbed defender 3.5? Well, it's a challenge of sorts! I'd just fit an adjustable stop under the accelerator pedal, although yes you could "tune" it for that.

Actually, I'd just get a different insurer!

I'm not sure which is easier wiring-wise, using an existing loom & modifying it or just making one from scratch, I'd tend to say just making one as the MS loom has a lot less in it than the P38 one.

You'd need fuel & spark for a 4.0 as it has no distributor, on an earlier lump you can retain the distributor and use that if you want.

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Hmmmm

I seemed to have completely missed this thread, just read it and have a 2p worth to add

3.9 and 4.0 both are good, they are the same really in serpentine format.

The 4.0 is different as it has NO dizzy, so you are royally screwed in options to get it running,

you can bung a set of carbs on a 4.0 but you then have no way of shoving a dizzy in !. The 4.0 was a

marketing ploy of LR its a 3.9 with a different set of clothes :D

Getting a GEMS / Motronic system out of a P38 etc to run in your truck = don't try, its not easy and will cost

and it will be a bodge.

The V bet 3.9 is inferior to the 3.9 serpentine and the serpentine 3.9 has stronger cross bolted block

and a Crank driven oil pump, so, if you are buying a new engine to do go serp and not V belt.

Shove carbs on anything ??

Er, yes BUT

Carbs off a 3.5 onto a 4.6 = WEAK and you need to up the nedles and ferk about, also your are going to spend a bucket

of time and money on a Bodge, why not spend the time and money and get it spot on ?

if you get a 3.9 serpentine, that has a dizzy, get the Loom AFM and ECU etc and its 4 x wires to get it running, and then

if you wnat and like the idea you can go MS, you CAN't fir the 3.9 Serp EFI system to a 4.0 as there is NO dizzy hole !

You can shove a V belt front end onto a 3.9 Serp or a 4.0 serp, but frankly why do it, more time more money just to get an 20+

year old efi set up running, and its really not that great either.

MS yes OK I am biased, but on a 4.0 the kit is the cheapest at probably around £650 - £750 mark, in fairness this has reminded me to

sort the pricings out and put them "in Stock", but on the 4.0 you can save monies as you can use the existing coil packs and leads,

so you don't need a twin coil pack mounting and you don't need a CNC replacement dizzy etc etc, so the porice is attractive at say £700 all in

Now add up what you might get for your 4.0 loom and or ECU AFM etc etc to ofset, of go the other way and buy a 4.0 or (3.9) but without the wiring loom

ECU AFM etc etc etc and that should be a decent lump off.

I would steer away from 4.6s, I prefer the 3.9 serp above all engines inc the 4.0 one, 4.6s don't rev as free and a 3.9 have less problems, but

I would say whatever V8 you go for Top hat liners if your neding liners (drastic there are plenty of decent V8s out there for OK money) but ARP

Studs for the heads, composite gaskets, Duplex Chain and solid gears MILD cam and new followers, and a dynamic balance (les £s) than you would

think will give you a good solid reliable v8, if you go Lucas EFI green Non cat Tune resistor into the loom, and do NOT tune the engine as you

will have it run weak, and to get it right = a EPROM Chip into the ECU at £350 ish...oh just go MS :lol:

Hope the above is usefull

nige

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Um, you want to tune a 4.0 to give the same ~98bhp as a factory carbed defender 3.5? Well, it's a challenge of sorts! I'd just fit an adjustable stop under the accelerator pedal, although yes you could "tune" it for that.

Actually, I'd just get a different insurer!

I'm not sure which is easier wiring-wise, using an existing loom & modifying it or just making one from scratch, I'd tend to say just making one as the MS loom has a lot less in it than the P38 one.

You'd need fuel & spark for a 4.0 as it has no distributor, on an earlier lump you can retain the distributor and use that if you want.

I worded that a bit wrong, I meant standard tune for a 4.0, definitely not to make a 4.0 produce 3.5 power!

Nige, very helpful, thanks. Sounds like a 4.0 on MS is the way forward in my case, 3.9s are hard to find and big mileages when you do.

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So after all the thinking and advice from here, it was clear a later V8 on MS is the way to go. I've got myself a 4.0 Serp from P38, sold as complete with all ancillaries...

I don't know this engine at all, it is significantly different from my 3.5 :D

What are these pipes, why would they have been cut, do I need them? There are 3 or so on one side (circled) and a few on the other (arrowed).

Fourlitre3_zps6c0015e9.jpg

Close up:

Fourlitre4_zps108e1155.jpg

What is this wire?

Fourlitre1_zpsd03f87db.jpg

I haven't left seller feedback yet, so if anyone can say for sure if these are issues, I'd be interested.

Second question - these engine mounts, is there a conversion to the Defender style mounts? I had hoped they would be the same. Is there any changes to the mounts chassis side to be made?

Fourlitre2_zpsf78c9989.jpg

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Right, a bit of an update and another couple of questions. The 4.0 is now in the chassis, and I've started on the Megasquirt this week. As in other threads, I had to cut the AC bracket as it doesn't fit within the smaller engine bay, which of course meant a smaller belt was needed. However, there are two belts on the same part number according to my Land Rover dealer. So after getting the measurement of the belt's course, I purchased one. Now, the piece of string I used to measure it (technical I know, but stay with me) is actually shorter than the belt, and much shorter than the other (more expensive) belt I was offered. However, now the thing doesn't fit, and the belt tensioner doesn't actually move. I'm no mechanical genius, but to my mind if no part of the system is adjustable, it's not a tensioner, it's an idler pulley. :rolleyes:

So, does anyone know why a belt wouldn't fit on the set up I now have? I am assuming the belt tensioner is the left-most pulley in this picture. Keen students of observation will note the belt is not following the correct run in this photo, but if I could get it to go around the alternator then I wouldn't be making this post. :lol: It is barely an inch too short, and as stated - the belt is longer than the string suggests it need be. How can that happen?

DSC_0409_zps3ddae0a5.jpg

DSC_04081_zps084bef96.jpg

Secondly, on opening the rocker cover to take a look at the valves in anticipation of setting TDC for the MS trigger wheel install (Nige, please, please read your PMs) I have found this lovely mess. Clearly the 4.0 is well used, and I bought it to avoid having to strip another engine. It's not pretty, I know this, but is it far gone?

DSC_0411_zpsc3efe60c.jpg

DSC_0410_zps83d68591.jpg

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elbekko    51

The insides don't look perfect, but also not horrible.

The right belt should be ERR4461 [ L/R - V8 - Petrol - EFi - except air conditioning ]

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Bowie69    382

The insides look OK to me... well it's not like it is going to implode on you, I have seen MUCH MUCH worse.

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tacr2man    21

You might have been better off with the 3.9i serp engine , as that fits including the aircon ,as in my 110 until changed to tdi6 .

The inside view looks a lot better than most older RV8 .

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The insides don't look perfect, but also not horrible.

The right belt should be ERR4461 [ L/R - V8 - Petrol - EFi - except air conditioning ]

That's the number I have, which seems to me given how close it is to fitting, that the adjustment should be in the system and yet no where on the internet can I find anything about how to do so. On the 3.5 all you had to do was slacken the alternator!

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Yes the tensioner is the pulley on the left. Sometimes they seize up. If you put a 15mm ring spanner on the bolt in the centre of the pulley you should be able to pull it over against the spring.

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Bowie69    382

Exactly, 15mm spanner and turn it clockwise (from memory). It is stiff.

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elbekko    51

Yup. May need two spanners hooked together even, they're very stiff. Then you should be able to put it over the alternator.

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V8 Freak    73

I used to fit to all but the water pump pulley, rotate the tensioner with a 15 mm spanner and slip the belt down under the water pump pulley.

(My 4.6, no aircon, didn't have the extra pulley on the right... Might need to remove it to use the shorter belt...)

post-1475-0-28819800-1410024194_thumb.jpg

I found fighting the toothed pulleys was harder to do....

Neil

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