TD5 to V8

[FridgeFreezer]

As Bowie said, vastly overblown as people love a good scare story.

Also, if you buy a running P38 if it's not had a problem by now it's likely not going to.

[widget]

13 hours ago, Bigj66 said:

My R380 has the higher ratio transfer box off a Disco 2 fitted. Reading through a couple of members build threads I get the impression that this setup could be a bit over geared for even the 4.6 V8.

I’ve always assumed the V8 will out perform any of the Landrover Diesel engines in terms of both power and torque so I’d be interested to hear from anyone who has experience of this.

The air box arrangement also seems to present some challenges to get right. With that in mind does the GEMS engine plenum provide a bit more space for pipe work etc than the THOR?

I’ve got a Ninety with a D1 serp 3.9 V8 with R380 with tall 5th and 1.2 T box. 

The 1.2 is fine, but I will be swapping it for a 1.4 when I get the chance. It pulls fine but feels slightly ‘off cam’ below 80 in 5th on the Mway. 

 

[elbekko]

9 hours ago, Bigj66 said:

Another question regarding the issue of leaking thin walled cylinder blocks caused by poor machining. Was this quality issue ever resolved by Landrover before production of the Thor V8 ceased? Or, are the Thor engine blocks just as likely to have similar problems? 

Don't worry about it. As others have said, if it hasn't broken now, it probably won't. And don't let it overheat for too long.

[Escape]

I had a P38a 4.6 manual, that has a R380 mated to a Borg-Warner transfer box. The ratio of the transfer box is identical, 5th gear on the R380 is higher for the V8 at 0.73 compared to 0.77 for the TD5. So overall gearing was higher than yours will be, but it coped just fine with 32" tires on, even pulling heavy trailers. My 4.0 with the same gearbox did struggle at times, but that's beause the engine is in dire need of some TLC (mainly timing gear and cam). With a decent 4.6 you should have no problems at all. To add, the ZF4HP24 autobox has the same overall gearing in top, and even when the lock-up activates the 4.6 never struggles.

As said above, don't worry about the supposed problem with the engine blocks. If a V8 is still running today and you take some care of it, it will serve you for well for a long time to come.

There's not much difference in the intake ducting between a GEMS and a Thor. But the Thor does leave less room between the intake manifold and bulkhead, so you might not be able to route the intake as on the Defender 50th anniversary. If you go with MS, you don't need a MAF, so less space needed.

Filip

[Bigj66]

That’s a relief to hear as yes, there are many scare mongers out there.

I’ve still got some reading to do on the subject mostly earlier threads on the conversion and the problems others came across but I think I have most of the material now that I’ll need to get it done.

[FridgeFreezer]

Biggest PITA I had was the PAS pipe, you want the angled metal section from the outlet side of the pump or you'll never route a high-pressure flexi up there. Ask me how I know

[Bigj66]

16 hours ago, FridgeFreezer said:

Biggest PITA I had was the PAS pipe, you want the angled metal section from the outlet side of the pump or you'll never route a high-pressure flexi up there. Ask me how I know

How come a Defender V8 pipe can’t be used? I did read about this in your build thread and meant to ask.

[FridgeFreezer]

18 hours ago, Bigj66 said:

How come a Defender V8 pipe can’t be used? I did read about this in your build thread and meant to ask.

Different pump, different fitting, different angle and very tight routing.

This is the pipe you need..

 

This is how the local hydraulics place did it - clean up the end, compression olive fitting into a standard 3/8" BSP (I think) hose fitting so then a replacement hose is just a standard jobby. Did the same on the PAS box end if memory serves.

 

 

[=jon=]

On 1/23/2020 at 10:45 AM, FridgeFreezer said:

This is how the local hydraulics place did it - clean up the end, compression olive fitting into a standard 3/8" BSP (I think) hose fitting so then a replacement hose is just a standard jobby. Did the same on the PAS box end if memory serves.

I've just done similar for my 4.6 install, but my PAS pump was a different layout - there was a union on the pump end rather than a screw in fitting, and the union is on the passenger side of the pump, not on the top. We took the pump and the original PAS pipe that runs across the front crossmember to the local hydraulics supplier and they made up a flexi hose to fit and a standard compression fitting for the hardline across the crossmember. If I remember I'll take a pic of how it's setup tomorrow... 

[Bigj66]

11 hours ago, =jon= said:

I've just done similar for my 4.6 install, but my PAS pump was a different layout - there was a union on the pump end rather than a screw in fitting, and the union is on the passenger side of the pump, not on the top. We took the pump and the original PAS pipe that runs across the front crossmember to the local hydraulics supplier and they made up a flexi hose to fit and a standard compression fitting for the hardline across the crossmember. If I remember I'll take a pic of how it's setup tomorrow... 

Is yours the GEMS or Thor engine?

[Bigj66]

I’ve just been out to check the location of the TD5 radiator outlets and it looks like it shares the same arrangement as the V8 radiators do. Can I just retain my existing rad and expansion tank as it looks man enough for the V8?

For the exhaust, do I need to change the Thor manifolds for a set of Defender V8 ones and use the DV8 downpipes and Y piece? Once the Y piece is on the V8, does the rest of the system then run down the passenger (UK) side as the TD5 does?

I believe that the standard DV8 exhaust bore will probably be too restrictive for the 4.6 but that the TD5 intermediate and rear sections are okay. To mate up the V8 Y section to the TD5 intermediate section, do I need to fabricate a suitable joint or are there parts that will just bolt together and use the existing exhaust hangers?

My aim is to use as many off the shelf items as possible so that spares don’t become an issue in the future.

[=jon=]

47 minutes ago, Bigj66 said:

Is yours the GEMS or Thor engine?

It's a bit of a mixture - Thor inlet, Serp 4.6 bottom end and a random PAS pump that I sourced because we didn't have one. It's different to FF's GEMS setup above, anyway.. 

[=jon=]

4 minutes ago, Bigj66 said:

For the exhaust, do I need to change the Thor manifolds for a set of Defender V8 ones and use the DV8 downpipes and Y piece? Once the Y piece is on the V8, does the rest of the system then run down the passenger (UK) side as the TD5 does?

I believe that the standard DV8 exhaust bore will probably be too restrictive for the 4.6 but that the TD5 intermediate and rear sections are okay. To mate up the V8 Y section to the TD5 intermediate section, do I need to fabricate a suitable joint or are there parts that will just bolt together and use the existing exhaust hangers?

My aim is to use as many off the shelf items as possible so that spares don’t become an issue in the future.

For the exhaust - I'm using Disco / RRC (?) 3.9 cast manifolds, a RRC 3.9 Auto Y pipe, and a TD5 rear end from the Y pipe back. You need to modify the gearbox crossmember to clear, but then everything lines up and works with standard factory bits.. You may need to make up some hangars for the TD5 back half but it's not too far off fitting... 

[FridgeFreezer]

Exhaust wise you can't use the P38 manifolds as they foul the clutch slave, Disco 2, Disco 1 or RR cast ones are what you need, should go into standard Disco/RR Y-piece and then be roughly the right area to join up with stick Defender V8 system. I didn't have to touch the gbox crossmember.

I believe D2 or RRC 3.9 are the "nicer" manifolds as they go 4->1 rather than the earlier more fiddly 4->2->1 arrangement which is what I have.

This is the only photo I could find of my exhaust - stock crossmember, RRC manfiolds & downpipes into stock Defender V8 system:

 

Here's how the D2 system uses the earlier 4-2 manifolds but only into a single pipe... squishing!

 

 

[Bigj66]

So the 4.6 will run okay on a standard V8 defender system?

[FridgeFreezer]

1 hour ago, Bigj66 said:

So the 4.6 will run okay on a standard V8 defender system?

The back half yes, the front half (downpipes & Y-piece) of a stock Defender V8 system is really piddly and (I believe) won't mount to non-Defender manifolds because of angles and diameters etc.

Then again, I think people get overly exercised about exhausts and snorkels and things as if a 2-ton brick is an F1 car , with a petrol engine unless you're using wide-open-throttle at high RPM all the time you're not going to notice a restriction.

[Bigj66]

1 hour ago, FridgeFreezer said:

The back half yes, the front half (downpipes & Y-piece) of a stock Defender V8 system is really piddly and (I believe) won't mount to non-Defender manifolds because of angles and diameters etc.

Then again, I think people get overly exercised about exhausts and snorkels and things as if a 2-ton brick is an F1 car , with a petrol engine unless you're using wide-open-throttle at high RPM all the time you're not going to notice a restriction.

My original thoughts were to just fit a stainless defender V8 system including manifolds as it would probably flow better anyway. Would that be a better compromise or would that require TD5 crossmember mods too?

[Mo Murphy]

I have a pair of cast manifolds for sale if you need some 😉

Mo

[Bigj66]

3 minutes ago, Mo Murphy said:

I have a pair of cast manifolds for sale if you need some 😉

Mo

Thanks, I’ll bear that in mind if I go down the cast manifold route but I would like to look closer at the stainless four branch system although this will need to have the adapter fitted for the lambda sensor.

[Bigj66]

I took a photo of the engine bay earlier to use as a reference. What are the chances of keeping that existing airbox in place with a Thor manifold? On some of the threads I’ve read there seems to be enough room albeit a bit tight. I have a snorkel fitted that I would like to retain but it’s fitted to the drivers side which is a bit awkward given the layout of the V8 plenums.

Same question for the expansion tank.

 

[FridgeFreezer]

I've been there done that with the tubular headers and TBH I really don't like 'em - they kick out loads of heat (and steam when you go through a puddle) and if you wrap them to reduce that they absorb everything and steam more, plus you get glass fibre in your arms every time you work on the truck

Placement / air filter wise you might manage it, I fitted a 200TDi filter behind the engine as the old V8 dustbin-sized one was just a bit too tight, here's the space (in a factory V8 Defender):

 

[Bigj66]

1 hour ago, FridgeFreezer said:

I've been there done that with the tubular headers and TBH I really don't like 'em - they kick out loads of heat (and steam when you go through a puddle) and if you wrap them to reduce that they absorb everything and steam more, plus you get glass fibre in your arms every time you work on the truck

Placement / air filter wise you might manage it, I fitted a 200TDi filter behind the engine as the old V8 dustbin-sized one was just a bit too tight, here's the space (in a factory V8 Defender):

 

Is that valve at the rear of the engine supported by anything else other than the two hoses connected to it? Is it the idle air valve and will I need one for the Thor engine?

If I use the R380 V8 bellhousing will my engine sit in the same place as it does in yours?

Will I be able to use standard Defender V8 hoses for the engine to heater or need to make my own?

[FridgeFreezer]

1 hour ago, Bigj66 said:

Is that valve at the rear of the engine supported by anything else other than the two hoses connected to it? Is it the idle air valve and will I need one for the Thor engine?

If I use the R380 V8 bellhousing will my engine sit in the same place as it does in yours?

Will I be able to use standard Defender V8 hoses for the engine to heater or need to make my own?

OK in order:

1. Yes that's the idle air valve (Bosch 2-wire PWM valve), it has one of Nige's brackets under it and it's sort of clamped to it, or it would be if this photo was a bit later in the swap You don't strictly need one but it does help with warmup. I don't have one on the 109 and that will start & idle after a few seconds of gentle throttle even on cold days.

2. "If" is a big word... as far as I'm aware our ambulance is a factory standard V8 with a Defender R380 fitted later, with everything on standard mounts, standard props etc. so in theory... IF your transfer box sits in the same place as it would on a V8 Defender. As yours is a TD5 I've got no idea, they shifted the drivetrain around to gain space over the years so it could be forward or backward from the stock V8 position. Looking at the difference between a V8 and TD5 front prop would likely give a clue.

3. You'll need a fair length of heater hose and to tee into the bottom rad hose I think, the outlet on the inlet manifold is tapped 1/2" BSP from memory so that bit's easy.

Inlet manifold outlet, temporarily plugged:

 

Tee piece (eBay fan switch from AutoSiliconeHoses plus barbed adapter) goes into bottom hose for heater return:

 

 

[=jon=]

6 hours ago, FridgeFreezer said:

The back half yes, the front half (downpipes & Y-piece) of a stock Defender V8 system is really piddly and (I believe) won't mount to non-Defender manifolds because of angles and diameters etc.

Then again, I think people get overly exercised about exhausts and snorkels and things as if a 2-ton brick is an F1 car , with a petrol engine unless you're using wide-open-throttle at high RPM all the time you're not going to notice a restriction.

I went from a totally standard factory v8 exhaust system to the 3.9 cast manifolds / RRC Y and TD5 rear and could notice a difference on an asthmatic 3.5, so I'd imagine you'd notice it a lot more on a 4.6... 

I think a lot of the aftermarket tubular headers shift the power up the rev range at the expense of low end oomph - something to do with long collectors vs. short collectors. 

[=jon=]

28 minutes ago, FridgeFreezer said:

3. You'll need a fair length of heater hose and to tee into the bottom rad hose I think, the outlet on the inlet manifold is tapped 1/2" BSP from memory so that bit's easy.

From memory the Thor setup has a push fitting with an O ring and a securing bolt - there's a hard pipe that runs to the back of the manifold to which you can run a short length of heater hose to the defender heater. You can also replace it with one of these:

Thor 'Inlet Manifold Coolant Take Off' Pipe - Conversion Unit

https://www.megasquirt-v8.co.uk/ms_thor.php

I did very similar to you for the heater return to the bottom hose though... 

I also ditched the funny thermostat setup, used one of the kits from Nige and a straight fitting for a TVR out of the front of the block for the top hose...