TD5 to V8

[Bigj66]

Anyone changed their TD5 for a V8 in a 110?

Is it straightforward in terms of getting the engine sat on the mounts and bolted up to the gearbox?

[RedLineMike]

depends on what v8 you want to use, 

personally I wouldn't swap a td5 for a rover v8 

 

[FridgeFreezer]

Not heard of it but I like the cut of your jib.

I don't think you'll be able to keep your gearbox as bellhousing + input shaft are likely to be different lengths.

Mounts I've no idea, but that's usually jut a bit of cutting & welding, especially if you can get the mounts from a V8 chassis.

Plumbing will be quite different but if you play it right you should be able to use all standard Defender V8 parts in standard places, keeps it easy for maintenance.

[neil110]

Engine mounts for V8 are very different to TD5 but getting hold of V8 mounts form some of the conversion specialists is relatively easy.

The route of the exhaust can be a bit of a pig to sort out and might involve changing your gearbox X member (if you want an exhaust that can breathe) Though in my youth, I managed to mate a RR front section to the TD5 middle box and tail pipe, simply a matter of spending LOTS of money on a NAS Defender gearbox xmember or modifying the xmember from a discovery/RR.

https://www.brit-car.co.uk/product.php/241716/0/exhaust_1_piece_y_section_3_9_rr_ga_gt_

https://www.brit-car.co.uk/product.php/89164/0/crossmember_assembly_chassis_frame

https://www.ebay.co.uk/itm/Land-Rover-Discovery-chassis-cross-member-/352407636544?hash=item520d21ca40%3Ag%3AhFEAAOSwVL5a~n-N&nma=true&si=QQsD%2B7I0O2fz2DcqTIZmJKF8dNY%3D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

Edited January 24, 2019 by neil110

[Bigj66]

I’m looking into swapping the TD5 for a 4.6 V8 once again and from what I’ve read in other threads, as long as I start at the gearbox and work forward then it should be a case of repositioning the engine mounts. I say a 4.6 but is that the best version of this engine for a conversion or should I stick with a 3.9 SERP?

I have the R380 with the high ratio Disco transfer box so I think gearing should be ok to start with. That should also deal with the two props.

Will I need to find a V8 bellhousing and swap that over for the TD5 one or is it best to find a conversion plate? Presumably I’d need to use a V8 clutch and flywheel assembly off a V8 Defender?

I’d like to use as many standard parts as possible such as radiators, cooling pipes and exhaust but accept that things like exhaust hangers may need to be fabricated. Can I just buy a full Defender V8 exhaust system and use that?

If I bolt the engine to the gearbox and there is a gap of a couple of inches between the existing TD5 mounts and the V8 ones then could that gap just be bridged with a suitable bracket or the engine mounts modified to avoid the need to reposition the chassis mounts? It would be far easier for me to have engine mounts modified rather than have the chassis welded.

V8 ECU in the engine bay suitably protected with TD5 wiring adapted to suit? Is the engine loom on a TD5 independent from the rest os the loom and removable as a separate item?

The TD5 runs a high pressure fuel pump in the tank so can I retain the tank and pump or are the diesel and petrol pumps and chassis filters different for the V8?

Anything else that I’ve overlooked?

[FridgeFreezer]

Personally I think the 4.6 is best as there's no substitute for displacement in a big heavy vehicle, others will tell you the 4.0 and 4.6 are awful unreliable things and the liners will slip etc. etc... both mine have been great so I'm obviously lucky. The 4.0 and 4.6 give you larger journals and cross-bolted mains plus composite head gaskets, all worth having IMHO, and the late Thor ones drop 3bhp at the top end but gain ~23 torques and 400rpm lower 2600rpm instead of 3000, thanks to the bunch-of-bananas inlet manifold.

I don't know if the V8 bellhousing will swap onto a TD5 box, input shaft lengths/sizes could well be different (part numbers for shaft, clutch etc. would tell you). Never seen a V8-to-TD5 adaptor plate.

Defender V8 exhaust is quite skinny as it was designed for the carbed 3.5, the 3.9 Range Rover or 4.0 D2 manifolds, downpipes & Y piece should be about right and may join up with the back half of a later Defender system without too much faff. I bought a Defender V8 front half when I converted the ambulance and threw it in the corner in disgust

I don't think the TD5 fuel pump is going to enjoy being dipped in petrol but I could be wrong.

[Bigj66]

I suppose the 3.9 will wire up easily enough but I’m not sure what it will take to run the Thor ECU as a stand-alone or even if it can be done.

I’ll start having a mooch around the part numbers to see what goes with what.

[Bowie69]

You can run the 4.6 on a 3.9 ecu, but either way running on megasquirt will get you better results, and cab be done using existing sensors on the 4.6.

[Bigj66]

41 minutes ago, Bowie69 said:

You can run the 4.6 on a 3.9 ecu, but either way running on megasquirt will get you better results, and cab be done using existing sensors on the 4.6.

Do you need to change anything on the 4.6 to run it off the 3.9 14 CUX ECU? Will it fuel in the same way? Which is best, the GEMS or Thor engine?

I’ve never had anything to do with MS so how easy is it to build and wire in? Do they come pre-mapped for the 4.6? I’ve fitted a stand alone ECU to my Capri so have a rough idea how to fit one.

[Bowie69]

To run the 4.6 on 3.9 gear you need the 3.9 plenum/intake setup essentially, think of it as converting your 4.6 to 3.9 set up on the top. Obviously you lose the more modern inlet manifold this way, so no ideal, but all doable. 

MS is not pre-mapped to a 4.6, no, but you can turn on the fly with a wide and, and get pretty much bob-on. You can buy kits to convert your 4.6.... Not especially cheap, but they work very well. 

[FridgeFreezer]

MS depends how you want to do it - you can solder an ECU together from scratch and build your own loom or you can buy a complete kit off Nige at Megasquirt-v8 which is as near to plug & play as possible, but it's spendy.

I think Nige does ship ECU's with decent maps for whatever engine you've got but there'll always be fine tuning to be done once it's in.

I've just finished (re)doing the whole thing from scratch on my 4.6 109 and did the same on the 4.6 swap in the ambulance so there's two write-ups for you straight off the bat

Both of them now have the ECU & EDIS ignition module tucked behind the standard dash.

[RedLineMike]

On 1/11/2020 at 4:45 PM, FridgeFreezer said:

I don't think the TD5 fuel pump is going to enjoy being dipped in petrol but I could be wrong.

externally the pump looks much like the intank bosch 044 stye pumps, as for how they would cope with petrol, i havent tried it but would suspect that it would probably work

[Bigj66]

4 minutes ago, RedLineMike said:

externally the pump looks much like the intank bosch 044 stye pumps, as for how they would cope with petrol, i havent tried it but would suspect that it would probably work

The VDO in tank pump I have in the TD5 looks exactly like the one I had in my Softdash RRC 3.9 but whether they run at different pressures or are designed for a particular type of fuel is something I need to find out.

[Bigj66]

To change the gearbox input shaft and bell housing do you need to remove the whole box or can it be removed with the engine out and access via the engine bay? 

Looking at a parts catalogue I can see that there are bell housings and clutch release assemblies listed for the R380 V8 gearbox so would it be correct to assume that the main case on the R380 has a common bolt pattern to allow either a V8 or TD5 bell housing to be bolted to it? I’m not that good on gearboxes but I seem to remember that the input shaft can be removed separately with the bell housing and it’s not part of the main box?

[lo-fi]

Gearbox work is really best not done in the vehicle, its really hard to keep everything clean. Not that much work to hoik it out of you've got that far anyway. I've not worked on the R380, but if it's anything like the boxes I have opened up you're in with a chance of being able to swap the input and housing without ripping it all apart. I'd give Ashcroft a ring, ask for the parts involved and some pointers on whether it's possible or practical.

Regarding fueling a 4.6 with the setup from a 3.9... With the benefit of experience putting a fueling system from a 3.5 to put on a 3.9 myself: you'd find it nigh on impossible to get it to run right and you've got little option for tweaking it with the standard ecu. Frustration looms down this path. A serp 3.9 if you're not comfortable doing a megasquirt install is going to be the sweet spot for a good outcome without a shadow of a doubt. 

I like the thinking, though. Down with the Devils Fuel^TM!!!

[elbekko]

I'd just swap the TD5 pump with one from a Thor or GEMS (depending what you go for), they should be pretty much a straight swap anyway. We've experienced first-hand that the wrong fuel pump can give serious tuning issues, so just stick with what's known to work I'd say.

[Eightpot]

There's another in tank fuel pump for the NAS V8 which looks like it may have the same fitment as theTD5 pump - ESR3928 

[Retroanaconda]

The bellhousing is easy (apart from finding one - V8 R380s are not common), the bolt pattern on the box is common as you suggest. In fact it's even the same as the LT77 bolt pattern however you can not use an LT77 V8 bellhousing as it's a different length.

The input shaft splines are the same I believe, but I'm not sure about the length or the diameter of the spigot bush. Changing the input shaft requires the gearbox to be partially dismantled. The easiest way will be to send your Td5 box to a rebuild place and ask them to put a V8 input shaft onto it, or if you're capable then dismantle yourself and build it back up.

You'll need to change the engine mounts as already mentioned, but everything else should be able to stay in the correct position. You can retain your Td5 wiring looms and dash/instruments, with minor modifications.

[Bigj66]

2 hours ago, Retroanaconda said:

The bellhousing is easy (apart from finding one - V8 R380s are not common), the bolt pattern on the box is common as you suggest. In fact it's even the same as the LT77 bolt pattern however you can not use an LT77 V8 bellhousing as it's a different length.

The input shaft splines are the same I believe, but I'm not sure about the length or the diameter of the spigot bush. Changing the input shaft requires the gearbox to be partially dismantled. The easiest way will be to send your Td5 box to a rebuild place and ask them to put a V8 input shaft onto it, or if you're capable then dismantle yourself and build it back up.

You'll need to change the engine mounts as already mentioned, but everything else should be able to stay in the correct position. You can retain your Td5 wiring looms and dash/instruments, with minor modifications.

Cheers.

I’ve only just had my rebuilt Ashcroft box put back in so I was really hoping I would be able to leave it in situ and unbolt the bell housing and the input shaft assembly with access through the engine bay once the engine is out.

If it can’t be done then so be it, I’ll have to drop the box too but if I can avoid it I’d like to.

Ashcrofts also sell the V8 bell housing.

If I was to use the 14CUX ECU with a 3.9 SERP engine then there’s only a few additional wires needed to get it running isn’t there?

I was reading on the RPI website that the 4.0 is basically the same Cc as the 3.9 so if that’s the case, would a 14CUX ECU run a 4.0 Disco or P38 engine ok?

I also read that the 4.6 GEMS ECU has both a fuel and ignition chip that can be mapped but that on the P38, they were coded to the vehicle itself and to retrofit to another vehicle, the ECU will need to be ‘unlocked’. Can anyone explain how the various ECUs are wired or point me towards some information please? I’m struggling to clearly understand what options are open to me.

If I can use the GEMS factory ECU then I would prefer to have a 4.6 but if it’s too much hassle to wire in and get running then I’ll look at one of the smaller capacity engines.

 

[lo-fi]

1 hour ago, Bigj66 said:

If I was to use the 14CUX ECU with a 3.9 SERP engine then there’s only a few additional wires needed to get it running isn’t there?

I was reading on the RPI website that the 4.0 is basically the same Cc as the 3.9 so if that’s the case, would a 14CUX ECU run a 4.0 Disco or P38 engine ok?

Info on V8 variants here. The 14CUX just needs (give or take) ground and power besides all its connections to the engine. The 4.6 GEMS I've not seen discussed so much - sounds like it needs to be fed an immobiliser code if that info you've got is correct. If you can find someone to unlock it and can use the entire system from a 4.6, there's no reason not to do so, though. It's the better setup regardless of the extra displacement.

[FridgeFreezer]

2 hours ago, Bigj66 said:

I also read that the 4.6 GEMS ECU has both a fuel and ignition chip that can be mapped but that on the P38, they were coded to the vehicle itself and to retrofit to another vehicle, the ECU will need to be ‘unlocked’. Can anyone explain how the various ECUs are wired or point me towards some information please? I’m struggling to clearly understand what options are open to me

Are you determined to go the factory ECU route then? Megasquirt will run anything with wiring about the same as a Hotwire loom in terms of complexity.

Here's the whole thing, fuel & ignition, to give an idea:

[Escape]

Yes, the GEMS (and Bosch) need a signal from the immobiliser. In the P38 this comes from the BECM, easy enough to sync to a different P38, not so easy to run on its own. I'm not sure how it was done in the Defender 50th anniversary or the Disco2. Both do have a security module, so I guess it was modified to give a similar signal as the P38 BECM. TVR also used a variant of the same engine management at some point I believe, might be a possibility.

Easiest, as Fridge says, is to go MegaSquirt. If only for all the extra possibilities when it comes to tuning. It's easy enough to use the standard loom (either 14CUx or GEMS) and wire it in to the MS connector. That way you can keep all the connectors to sensors etc, but it does limit you as to where you can mount the MegaSquirt because of cable length. Ideally mount it in the same spot as the standard ECU.

Filip

[Bigj66]

9 hours ago, FridgeFreezer said:

Are you determined to go the factory ECU route then? Megasquirt will run anything with wiring about the same as a Hotwire loom in terms of complexity.

Here's the whole thing, fuel & ignition, to give an idea:

It looks very similar to the Emerald K6 I used on my Cosworth V6 so no dramas with making a loom but just having to power up a factory ECU would have saved me a bit of work and kept everything as standard as possible that’s all. I believe that RPI will unlock the GEMs ECU for a fee so I might enquire with them to check.

 I noticed when reading your very excellent write up of the installation into the ambulance that you needed to make a pointer for the timing. Does that not come as part of the kit? The other thing is that I’m not so savvy with mapping and tend to leave that to those who are which is why I’m a bit more nervous about going down the aftermarket route but then again I’ve never used the MS so not sure how easy it is to use when you have issues like you had with your cold idle?

Do I also need to plan for a remote oil filter?

It sounds like the Thor engine is the one to have. Will that run off MS too? Does the Thor have the same factory ECU as the earlier 4.6?

Thanks all for the help and feedback so far.

 

[RedLineMike]

On 1/13/2020 at 8:04 AM, Bigj66 said:

The VDO in tank pump I have in the TD5 looks exactly like the one I had in my Softdash RRC 3.9 but whether they run at different pressures or are designed for a particular type of fuel is something I need to find out.

td5's run at 4 bar of fuel pressure, i would assume that a rover v8 would be similar, i know my LS runs at just under 4 bar, @FridgeFreezer will probably know more about the rover v8 fueling requirements

[RedLineMike]

as a thought if you wanted to, you could use the td5 fuel filter for the v8, im currently using a td5 filter head assembly for a fuel filter on my LS although it has the plumbing simplified slightly from 4 connections to 2