Serp 3.9efi disco engine into defender 110 V8 idiots guide.

[johndregg]

Ive aquired a 3.9efi engine from a rusty disco, well its actually still in the disco and running well. I want to fit it into my defender in place of the 3.5 low comp twin SU motor thats already in there.
Is there a guide for what i need to remove from the disco (engine loom, ecu? etc etc)? where the parts are situated on the disco? does the wiring just unplug or will it need cut and resoldered.
I basically dont want to damage anything that i will need later.
I'm also going to need a wiring diagram when i finally get it into my defender.
Bear with me please, and thanks in advance for the help!
John

 

[cooltide]

It'll become obvious as you get into it put just pull one out, put one in whole.
You'll need a new clutch plate and exhaust header to head gasket set.
The ecu is under the seat, unplug and feed through bulkhead. Don't need to reuse the exhaust lambda sensors if fitted, don't need to reuse the road speed sensor likewise.

You do need a suitable high pressure fuel pump and lines, I'll Google and put a linky up tomorrow.
It's Friday and I'm off out, must be my birthday

 

[discool]

ECU is not under the seat its behind the drivers kick panel so start from there, the 3.9 ECU requires a speed signal and that's from a transducer fitted to a 3.9s transfer box, the same item is used by the speedo, a couple of relays are also required.
There is a diagram in the Haynes manual for the disco.

 

[johndregg]

Cheers guys. I'll get the ecu loom out along with the whole engine, rad/oil cooler, engine loom, speed transducer?
Be in touch once I've got it all on the garage floor.

 

[discool]

With every thing securely labelled that's all u can't do for starters, i can scan and post the EFI page from my Haynes but I'm sure its out there on the www already.

 

[johndregg]

The disco is being broken, so I'm assured I can come back for any bits I find I need as I go along.

 

[cooltide]

http://www.ebay.co.uk/itm/MG-MAESTR...EC-REPLACEMENT-FUEL-PUMP-MLR-GB-/121385776660

It says 3.5v8 compatible but will be fine for all rover v8 capacities. This is an inline pump and needs to be mounted lower than the tank (efi pumps don't suck well).

If your discovery has cats, you'll have to change the tune resistor, assuming your 110 doesn't run cats.

The road speed sensor helps prevent stalling under load e.g. when stopping in drive, winching. Mine has no issues running without one on a manual lt77

 

[johndregg]

What about RRC in tank pump?
And will my current fuel cut off valve on my lpg system work in the same way? I.e. Inline before the injector system?
My 110 runs stainless tubular headers through a 22" cherry bomb "silencer"

 

[jamesmartin]

What about RRC in tank pump?

thats what ive used several times as long as its the efi hp

 

[jamesmartin]

http://www.ebay.co.uk/itm/MG-MAESTR...EC-REPLACEMENT-FUEL-PUMP-MLR-GB-/121385776660

It says 3.5v8 compatible but will be fine for all rover v8 capacities. This is an inline pump and needs to be mounted lower than the tank (efi pumps don't suck well).

If your discovery has cats, you'll have to change the tune resistor, assuming your 110 doesn't run cats.

The road speed sensor helps prevent stalling under load e.g. when stopping in drive, winching. Mine has no issues running without one on a manual lt77

mine ran well without too,

 

[johndregg]

Well the engine and the whole loom including lambdas and lpg wiring and ecu loom are home. Need to borrow a crane to get it from the landy to the stand in the shed.

 

[johndregg]

Bit of a progress report. Got the engine onto a stand into the garage and stripped the ancillaries off it.
Got my paint scraper out and scraped off the muck and rat poo ( under the inlet manifold). Took the front cover off, cam out and fitted a crower 500229 instead with new followers and timing gear.
Next up is refitting the inlet and getting it ready to fit to the landy.

 

[15MAS]

I am about to start a very similar project with the help of a local mechanic. To save mechanic time and I am sourcing the missing/conversion parts and already hitting obstacles, it seems most people want to put Turbo Diesel engines in not big petrol units. The donor car is a 3.9 serp manual Discovery with the transfer box and gearbox into a 95 Defender 110 2.5NA ex-mod. I am keen to get any pointers on some of these obstacles.

I have bought a R380 conversion kit for the gearbox from Ashcroft’s
The mil spec df Nader rad has an oil cooler and trying to source a rad that has the extra flow pipes for the inlet manifold as well as the oil cooler needed by the V8. Will a disco rad fit? I don’t fancy having to buy a NAS spec one.
I can’t find an exhaust system to fit the disco manifold and fit the defender mounting points etc. I have looked at the disco manifolds and they seem different to a regular 3.5 v8 Does anyone know whether the disco y pipe can be altered to fit with a defender V8 system?

Any help would be appreciated.Thanks

 

[wireman]

I put a Disco 1 engine into a 90 a few years back. The disco rad is too wide for the Defender slam panel IIRC, I just bought a V8 90 rad. As for the exhaust, I used a combination of V8 90 and Disco 1 pipes to get to the standard silencer but for the life of me I can't remember which ones I used. I know one of the down pipes didn't work as it fouled on the propshaft.

 

[cappers]

Like @wireman, I had a Disco 1 3.5 hot-wire put into my 90 last year. Used a standard V8 90 rad (non-NAS spec), Disco downpipes and Y-piece with a 90 turbo diesel mid and back end; subtle but obvious when booted Didn't have a Disco gearbox crossmember so modified the one on the 90 to make room for the exhaust. Couldn't fit the fan shroud to line up with the fan and the rad so used the original electric fan, which despite my misgivings, hardly comes on and the temp stays around 80-85 (VDU gauge with Disco sender so might be erroneous but runs fine). Mine has a RRC auto box and an Ashcroft oil cooler behind the rad.
Some details on LRUK: https://www.lrukforums.com/threads/3-5-v8-efi-from-a-k-reg-disco.232297/
PS it's a long rambling thread but there is info in there ; the conversion was done professionally but it took months for a number of reason including missing parts and and some serious but well hidden corrosion. Well worth it in the end

 

[15MAS]

Thanks for the response. The project is progressing nicely, the engine and gearbox are in and engine mounts relocated. We have used the disco r380 box with modified selector. I took the defender radiator to a classic car radiator place and the added an additional inlet pipe for the inlet manifold cooling. The defender has a fairly recent radiator with oil cooler which I am hoping will keep the engine cool. The disco had been modified with electric fans that I have moved to the defender, no viscous.

I have bought an edelbrock carb and manifold which I am looking forward to getting on. The efi system from the donor car was messed around with, drilled inlet manifold and had a LPG kit which I didn’t want on the defender. Went old school with a carb.

I am in the interim going to use the disco Y pipes which have cats and hope a defender system can be rigged up from there. I have also salvaged the V8 disco cross member to give the extra clearance. Hoping I can get some exhaust options on the floor and see what might join at the parts place.