300tdi conversion

[gti-90]

Hi all, i know engine conversions have been covered many times before, so apologies. But theres alot of conflicting ideas and theories it would seem to whats longer and shorter etc.

I want to put a 300tdi and r380 from a disco into my 86 90. Was 2.5n/a converted to 3.9 but a change is needed.

If i use standard defender 300tdi props connected to my early lt230, it should be in standard posistion? correct? Then the engine should be in "standard" 300tdi posistion?. And all standard off the shelf parts should fit? Ashcrofts do a Selector rail kit that allows use of a defender gear stick.

Will i need to modify seat box and tunnel?

Also what is worth doing on 300 before fitting? Water pump gasket? Timing belt? What else?

thanks

[Lewis]

If you put the transfer box where is should be then the engine will end up slightly further back than a factory defender 300tdi, but much further forward than a factory 200tdi (or any other 4cyl).

If you fit the Ashcroft kit to the shifter then you will be able to mount a defender shifter turret to the disco g/box and it will end up in the correct position in the transmission tunnel so require no mods.

if you want the engine in the factory 300tdi defender position then use a defender 300tdi r380

[gti-90]

Hi Lewis, I was under the idea that defender and disco gearboxes were the same? Just the shifter mech different. The idea I had to use 300tdi props was to put the lt230 in 300tdi position than the engine would be in the factory 300tdi defender posistion? This would not be the case if there different. thanks

[vulcan bomber]

Hi Lewis, I was under the idea that defender and disco gearboxes were the same? Just the shifter mech different. The idea I had to use 300tdi props was to put the lt230 in 300tdi position than the engine would be in the factory 300tdi defender posistion? This would not be the case if there different. thanks

so was I, the slaves are on opposite sides however.

[dangerous doug]

Boxes are similar apart from selectors and input shafts. bell housings are a lot longer on the disco, which pushes the engine forward if you keep the transfer box in the same place. Input shaft is longer on a disco box so you can't get around that by fitting a defender bell housing

I'm 90% done with a disco 3.9/r380 conversion into a 110 200tdi and have had no problems with fitment so far. I fitted the Ashcroft selector which was spot on. Only thing I needed to change for the fitment were engine mounts.

[gti-90]

Hi doug, i will probably be wrong, but reading elswhere on the web it would seem there is no difference in bellhousing or input shaft betweeen the two? The part numbers for the bellhousings are the same FTC3921?..

I no that r380s on to 200tdi need the stumpy bell housing.

Vulcan bomber, the slave cylinder shouldnt cause a issue should it? Just route the pipes to suit?

[dangerous doug]

No, I may be wrong there as I've never come across a 300 defender unit only 200 which is the stumpy one as you say, and the disco one which is super long. The one on my v8 is comparable with the 300 disco in length.

I assumed this as they have to find the space from somewhere....... But as they say assumption is the mother of all f....

[Tetsu0san]

The Defender r380 gearbox crossmember will move the gearbox slightly further forward than the one you have now, which would put the engine in the standard Defender 300Tdi position. You can also use the Discovery gearbox crossmember but it will need to be modified to fit, although this is easy enough. But as this will bring the gearbox nearer the front you will need props from a later Defender (I think).

From what I have seen the Discovery and Defender r380 gearboxes are the same from a length and mount perspective, but the gearbox selector is different. Like you said though you can get a selector adapter so that would give you the Defender positioned gear lever.

So basically:

• Discovery gearbox and engine straight in - Same props, cut the seatbox for the gear lever and possible new pipework as it's 2" back from the standard 300Tdi position
• Discovery gearbox and engine straight in with Defender selector - Same as above but you don't need to cut the seatbox
• Discovery gearbox and engine with Discovery gearbox crossmember and Defender selector - Standard engine position but props may need replacing, and you need to mod the crossmember
• Discovery gearbox and engine with Defender gearbox crossmember and Defender selector - Standard engine position but props may need replacing

I've done a similar conversion on my 110 using a Discovery crossmember, Defender r380 and a Discovery 200Tdi. It had an lt77 geatbox fitted to a Transit engine when I got the 110 but it was originally a 2.5 diesel. All pipework from the donor Discovery more or less fitted but I had to get 300Tdi 110 props as the front was too long and the back too short. I also had to mod the turbo but you wouldn't need to do that as it's a 300Tdi. I also converted it to power steering which was literally a bolt on job. As I was using the Discovery radiator and intercooler I had to modify the radiator mounts on the chassis and also modify the radiator/intercooler cage to fit. Again, easy enough.

While the engine is out I would do as much on the engine as you can. Check all the core plugs (especially at the back), do the timing belt and maybe paint it?

[Tetsu0san]

Ah, just thought. If you move the gearbox forward you do need to cut the seatbox to accommodate the gearbox underneath it. Or get a 300Tdi/TD5 seatbox and bolt that in. I cut mine and I have a seatbox ready and waiting to fit but I just can't be arsed!

[gti-90]

Tetsu0san, i think looking into the future for ease of parts/reliability etc off the shelf standard 300tdi is the way to go.

I think ile go with option 3 and or 4. Disco engine box and lt230 in standard posistion with later defender 90 props. Gear selector kit, Then all hoses upfront etc should fit.

Mounts etc are easy enough as i can "weld"ish!

Things to do while its out.. i will have a go at the timing belt (never done 1 but im sure its in the tech archive), degrease and paint. New p gasket, core plugs how easy are these? And somewhere it was mentioned about a rear oil seal?...

Thanks for the replies jack

Edit just seen your new reply. I have the standard 2.5n/a seatbox and tunnel slightly modified to fit the zf4hp22 a little bit stretched its tight but fits. I do however have a td5 bulkhead and tunnel so fitting that box will be ok. Ile just need to modify the seat box face a bit rounder. The 90s just undergone a realy smart spray job so its got to be tidy.

[Lewis]

Hi Lewis, I was under the idea that defender and disco gearboxes were the same? Just the shifter mech different. The idea I had to use 300tdi props was to put the lt230 in 300tdi position than the engine would be in the factory 300tdi defender posistion? This would not be the case if there different. thanks

You are correct - I was mistaken with regard to the transfer box location. Tetsu0san's thorough reply has clarified it for me. It's the transfer box position and prop length between a disco 300 and r380 on 4cyl mounts and the defender 300 and r380 on 300 era mounts that causes the engine position to be slightly different

[Tetsu0san]

Tetsu0san, i think looking into the future for ease of parts/reliability etc off the shelf standard 300tdi is the way to go.

I think ile go with option 3 and or 4. Disco engine box and lt230 in standard posistion with later defender 90 props. Gear selector kit, Then all hoses upfront etc should fit.

Mounts etc are easy enough as i can "weld"ish!

Things to do while its out.. i will have a go at the timing belt (never done 1 but im sure its in the tech archive), degrease and paint. New p gasket, core plugs how easy are these? And somewhere it was mentioned about a rear oil seal?...

Thanks for the replies jack

Edit just seen your new reply. I have the standard 2.5n/a seatbox and tunnel slightly modified to fit the zf4hp22 a little bit stretched its tight but fits. I do however have a td5 bulkhead and tunnel so fitting that box will be ok. Ile just need to modify the seat box face a bit rounder. The 90s just undergone a realy smart spray job so its got to be tidy.

Timing belt is easy but make sure you get the right kit. There are a lot of stories of the cam belt rubbing inside the timing chest and I know Land Rover did a later modified kit for certain engines. It's worth investigating and getting the right one.

If you are separating the engine and gearbox then yes, might as well change the rear crank seal. But obviously don't skimp on the brand. Geniune all the way.

I only recommend checking the core plugs at the back as it's a faff to do when in situ. I suppose just check to see if they look like they're leaking. There are oil ones and water ones. The water ones will be the only ones that might need replacing.

[ejparrott]

Don't confuse the stumpy R380 which is the direct replacement for an LT77 with the normal R380 defender gearbox

[Kaitsu]

On 9/21/2015 at 7:00 PM, Tetsu0san said:

The Defender r380 gearbox crossmember will move the gearbox slightly further forward than the one you have now, which would put the engine in the standard Defender 300Tdi position. You can also use the Discovery gearbox crossmember but it will need to be modified to fit, although this is easy enough. But as this will bring the gearbox nearer the front you will need props from a later Defender (I think).

From what I have seen the Discovery and Defender r380 gearboxes are the same from a length and mount perspective, but the gearbox selector is different. Like you said though you can get a selector adapter so that would give you the Defender positioned gear lever.

So basically:

• Discovery gearbox and engine straight in - Same props, cut the seatbox for the gear lever and possible new pipework as it's 2" back from the standard 300Tdi position
• Discovery gearbox and engine straight in with Defender selector - Same as above but you don't need to cut the seatbox
• Discovery gearbox and engine with Discovery gearbox crossmember and Defender selector - Standard engine position but props may need replacing, and you need to mod the crossmember
• Discovery gearbox and engine with Defender gearbox crossmember and Defender selector - Standard engine position but props may need replacing

I've done a similar conversion on my 110 using a Discovery crossmember, Defender r380 and a Discovery 200Tdi. It had an lt77 geatbox fitted to a Transit engine when I got the 110 but it was originally a 2.5 diesel. All pipework from the donor Discovery more or less fitted but I had to get 300Tdi 110 props as the front was too long and the back too short. I also had to mod the turbo but you wouldn't need to do that as it's a 300Tdi. I also converted it to power steering which was literally a bolt on job. As I was using the Discovery radiator and intercooler I had to modify the radiator mounts on the chassis and also modify the radiator/intercooler cage to fit. Again, easy enough.

While the engine is out I would do as much on the engine as you can. Check all the core plugs (especially at the back), do the timing belt and maybe paint it?

I'm interested to swap 300Tdi / R380 into my 200Tdi / LT77 Defender long wheelbase (110 pick up). As with the points 1 and 2, suggests the engine and gearbox will sit in without mods, to brackets in chassis, other than cuts for the selectors and probably some hoses/piping. Is that correct?

[Chicken Drumstick]

7 hours ago, Kaitsu said:

I'm interested to swap 300Tdi / R380 into my 200Tdi / LT77 Defender long wheelbase (110 pick up). As with the points 1 and 2, suggests the engine and gearbox will sit in without mods, to brackets in chassis, other than cuts for the selectors and probably some hoses/piping. Is that correct?

You are probably off starting a new thread, likely to get more replies and info. If there isn't anything wrong with your current engine/gearbox. The swap would just cost money with no gains IMO. Same power, same torque, same mpg, same revs. And while the R380 is in theory stronger, the majority I've driven have been less nice to shift than an LT-77.

[monkie]

9 hours ago, Kaitsu said:

I'm interested to swap 300Tdi / R380 into my 200Tdi / LT77 Defender long wheelbase (110 pick up). As with the points 1 and 2, suggests the engine and gearbox will sit in without mods, to brackets in chassis, other than cuts for the selectors and probably some hoses/piping. Is that correct?

What is leading you to consider this swap?

[Tetsu0san]

20 hours ago, Kaitsu said:

I'm interested to swap 300Tdi / R380 into my 200Tdi / LT77 Defender long wheelbase (110 pick up). As with the points 1 and 2, suggests the engine and gearbox will sit in without mods, to brackets in chassis, other than cuts for the selectors and probably some hoses/piping. Is that correct?

I wrote a massive long reply to this last night, but it seems to have disappeared! Anyway, I know I deliberated for a long time about whether I should leave the gearbox where it is or move evertying forward to the 300Tdi position, and although I did have to modify the seatbox I'm glad I did make this choice. Yes it was a bigger job, but everything else just slotted into place.

I have to agree with @Chicken Drumstick to a degree in saying that you'll not really gain anything doing this, apart from the ability to get parts easier. But if you do do this and you're going to leave the gearbox in the original place then you will lose the abaility to buy a lof ot of the shelf parts as nothing will be standard, mostly at the front of the engine, and you may have to shorten part of the exhaust too. If you're OK at fabricating then it's probably not an issue.

 

[fmmv]

If you do decide to do the swap and retain the original engine position, I believe the oil filter will clash with the right side engine mount. There is a bracket design on this forum to circumvent that problem.

[Tetsu0san]

18 minutes ago, fmmv said:

If you do decide to do the swap and retain the original engine position, I believe the oil filter will clash with the right side engine mount. There is a bracket design on this forum to circumvent that problem.

If he's using an R380 from a Discovery then the engine will not be in the original position. The engine will be moved further forward due to the longer bellhousing, but depending on what he does with the gearbox this will dictate how far forward the engine will be. Standard 300Tdi crossmember position (with cutting/replacing the seat box, new props etc) or slightly further back.