3.9 into defender???

[18 stoner]

In short, my 3.5 V8 station wagon is tired.

So, whats the ins and outs of putting say a 3.9 (possibly disco) into it?

Had a browse around and cant seem to find anything in much detail on this but appologies if its been covered before

I'm after hard basics really, like is it MAJOR hassle fitting an ECU, or would my carbs go on the 3.9? If so will they need re jetting etc?

Cheers in advance, Pete.

 

[Dr_evil]

Same size and mounting position, carbs would work as seen a few on youtube, EFI just needs plugging into the electrics.

Easy for me as my new engine came labeled with what connections need going where

 

[craigyb]

Same size and mounting position, carbs would work as seen a few on youtube, EFI just needs plugging into the electrics.

Easy for me as my new engine came labeled with what connections need going where

and hes still fannying about had it fer ages and just keeps talking about it

 

[Dr_evil]

and hes still fannying about had it fer ages and just keeps talking about it

feck off I'm dropping it in on saturday


only just started to get a shift on now, managed to get an engine crane nearby too

 

[buckshot]

feck off I'm dropping it in on saturday


only just started to get a shift on now, managed to get an engine crane nearby too

on past experiance that's about right

 

[Dr_evil]

on past experiance that's about right

be the third time I've put the same engine in :doh:

 

[buckshot]

be the third time I've put the same engine in :doh:

think the lumps trying to tell ya something

 

[Dr_evil]

think the lumps trying to tell ya something

Possibly I has gotten a new gearbox for it now that fits as well as new mounts


so alls well

 

[buckshot]

Possibly I has gotten a new gearbox for it now that fits as well as new mounts


so alls well

tbh few guys i lane with have v8's and they are all a pain in the arse , cant say they do a lot that my old 200tdi does'nt also do at a third of the fuel cost .
they sound nice and can leave mine at a junction but thats about it

 

[Dr_evil]

tbh few guys i lane with have v8's and they are all a pain in the arse , cant say they do a lot that my old 200tdi does'nt also do at a third of the fuel cost .
they sound nice and can leave mine at a junction but thats about it

I only get 25mpg in the disco so 22 in a series at worst on motorway isn't going to bother me may even get better than 25 tbh

Picking up a new engine hoist tomorrow and the exhaust pipes

 

[craigyb]

I only get 25mpg in the disco so 22 in a series at worst on motorway isn't going to bother me may even get better than 25 tbh

Picking up a new engine hoist tomorrow and the exhaust pipes

More like 12mpg

 

[Dr_evil]

More like 12mpg

We shall see the guy at the scrap yard has a 109 V8 and he said he got 25 on a long run

 

[craigyb]

We shall see the guy at the scrap yard has a 109 V8 and he said he got 25 on a long run

you ever heard of lieing?

 

[Dr_evil]

you ever heard of lieing?

Yes but either way it won't be too much worse than my disco

 

[POAH]

you ever heard of lieing?

or his maths suck lol

 

[griffman]

Ladies ladies ladies................................................................

stop bickering and give the man some tips on how to install his 3.9.

Your carbs will work fine - you MAY have to put bigger jets in - wait and see.

You will have more torque, more power, and if you put in a 1.2 transfer case a much nicer drive as well - probably more economy too..................

I take it you have an LT85 gearbox - stick with that.

 

[MattMatt]

I'm after hard basics really, like is it MAJOR hassle fitting an ECU, or would my carbs go on the 3.9? If so will they need re jetting etc?

It's not hard. The 3.9 is the same size and the wiring for the ECU etc is easy if you have the wires labled up but if you have a wiring diag it's not difficult to sort out. I have SUs on my 3.9 and it goes well although I have rebuilt and rejetted them. I think they were BBW jets but I will have to check. Keep the 3.9 dizzy as it's electronic and I swapped the alternator to replace the aircon pump to keep thinks low and neat. Might need a remote oil filter if you haven't already got one.

Nop - totally wrong - they were BCG needles

 

[18 stoner]

Cheers fellas, all sounds fairly straight then. My old lass has got very tired now, supping fuel like no tomorrow due to being toed constantly to get anything out of it. At present its struggling to hit 60 and wont go over 70 at all to give you a clue how low compression is!

My thinking was, the motor needs a total overhaul anyhow, so why not go for a tad more grunt that the bigger motor has, so here we are.

Ladies ladies ladies................................................................

stop bickering and give the man some tips on how to install his 3.9.

Your carbs will work fine - you MAY have to put bigger jets in - wait and see.

You will have more torque, more power, and if you put in a 1.2 transfer case a much nicer drive as well - probably more economy too..................

I take it you have an LT85 gearbox - stick with that.

Cheers for that, my carbs are actually from a P6 Rover Car, so guess they maybe ok to try as the origionals were shot. Either way if I go with a carb set up, I have a feeling an overhaul/re-jetting may be a must.

As for box, she is running the 85 as standard station wagon so I guess I got the right box, but not so bothered about the extra ratio as this ole girl only does about 1000 miles a year.

It's not hard. The 3.9 is the same size and the wiring for the ECU etc is easy if you have the wires labled up but if you have a wiring diag it's not difficult to sort out. I have SUs on my 3.9 and it goes well although I have rebuilt and rejetted them. I think they were BBW jets but I will have to check. Keep the 3.9 dizzy as it's electronic and I swapped the alternator to replace the aircon pump to keep thinks low and neat. Might need a remote oil filter if you haven't already got one.

Nop - totally wrong - they were BCG needles

Cheers, looks like the leccy shouldnt take too much sorting then if I can pick up all the bits with another motor.

Deciding which way to go now is the difficult one Perhaps see if I can find a good motor with all the leccy bits then go from there. Seems to be lots of folk seem to want to sell the lump without the ecu etc, so if its one of them, carbs it will be!

Cheers all for your help fellas

 

[18 stoner]

Ok, so it looks like ive found a nice 75k mile 3.9 disco with a sweet engine.

Question is, for you guys who have possibly had both, whats got the most grunt, a carbed 3.9 or a standard efi?

Im not bothered about economy, just want the sweetest version I can get with what I've got!

 

[griffman]

Read Eliot's website - there is an excellent sections under the 'ENGINES' heading about tuning the rover V8

Eliot Mansfield's twin turbo chevy Dakar 4x4

it is all there - and very well written too - I had found it very useful over the years