Thread: Fitting 3.9 in place of 3.5 Discovery

Keep all the serp belt bits on it and go pilfer all the bits out of the later disco and ad them to yours things like the oil cooler lines and the later rad get all the EFI gear and loom and computer for the 3.9 as well

You will need a spacer for the front of the crank if you use the old cover on a later engine. These are available from any specialist.
That is about all AFAIR.
Howeever it is better to use the new oil pump etc, so if the engine comes with ancilliaries then use them and adapt the electrics etc.
Regards Philip A

Whats the spacer for

I had another look at the Rover V8 engines book and you should not need a spacer. The spacer is to take up the width of the distributor drive on distributorless engines so that the front pulley can be tightened onto a shoulder.
However seeing you have a distributor engine this should not be necessary.

However I then thought of another thing. You cannot use the 98 distributor if you use the 3.5 front cover as the 98 does not have an oil pump drive.

Regards Philip A

Thanks for the reading dude

So if i leave it as is it should just drop in

The only thing i can see being a hickup is what to do about the Fan the new motor doesn't have a viscous fan it has thermos form the pictures ive had a look at on the net

If it doesn't have a Viscous fan it obviously doesn't need the one of my old motor so i don't need to change the front cover

Does that sound right the only reason i would change the front cover would be to allow fitting of the fan

The 93 disco has both the viscous fan and thermos 2x 10 inch roughly

Might be babling a bit but im learning

Originally Posted by steve_35

Thanks for the reading dude

So if i leave it as is it should just drop in

The only thing i can see being a hickup is what to do about the Fan the new motor doesn't have a viscous fan it has thermos form the pictures ive had a look at on the net

If it doesn't have a Viscous fan it obviously doesn't need the one of my old motor so i don't need to change the front cover

Does that sound right the only reason i would change the front cover would be to allow fitting of the fan

The 93 disco has both the viscous fan and thermos 2x 10 inch roughly

Might be babling a bit but im learning

No you need to change the front cover if you don't have all the accesories off the 3.9, including the oil cooler and pipes. Even though everything you own on the 3.5 will bolt on to the 3.9 its not a beginners job. Some of the bolts are hard to get at. You will need proper tools. Like an engine crane. Socket to undo the crankshaft nut. Spanners that don't slip. Long extension bars to reach the back of the engine from below. This is going to take you quite a lot of time and learning.

Originally Posted by steve_35

The 93 disco has both the viscous fan and thermos 2x 10 inch roughly

x2 on what Bee utey said +

thermo fans? .... they are A/C fans only! .... NOT SUITABLE or set up for cooling your radiator

That s why im asking questions i dont want to go and rip stuff out if i am going t have problems
ill just take it the mechanic and get them to do it if its a big hassle

It should be coming complete with ecu and airflow meter all the other goodies as i did explain to the guy what is was for and he knows land rovers so i think it should be all there ready to go in without to much fuss

I got it from AJG spares in QLD

i have worked on old Holden for years but this isn't a Holden that's for sure