Which v8 engine would you have 3.5 or 3.9

dio99 · Jan 4, 2017

I have just bought a defender 90, I have the option of having a V8 3.5 L or a V8 3.9 L, this will be fitted by the mechanic that is selling the defender 90 to me. He is also fitting an automatic gearbox.
Which engine would you choose 3.5 or the 3.9, if your choice is the 3.9 I also have the option of having efi or a carb fitted.

jamesmartin · Jan 4, 2017

id have a 3.5 high compression with 3.9 cam and hot wire efi

cooltide · Jan 5, 2017

As above, you need to know compression ratio of 3.5 and what carb is offered. I'd only take the 3.5 if it was done well

discool · Jan 5, 2017

My experience the 3.5 EFI's run a lot smoother than the 3.9, I use to think my 3.5 engine had stopped when sitting in traffic, but then it was in an RR.

Rumour at the time (1989/90) was Land Rover only introduced the 3.9 to overcome any restrictions in performance as the RR was now being fitted with a catalytic converter.

Performance is a good reason for a 3.9... for me, but with a Defender performance may not be that important I suspect, so I'd choose the 3.5. I found fuel consumption is slightly better with the 3.9.

Haven't seen a 3.9 with a carburettors

Sent from my iPad Air in Madeira.

Disco1BFG · Jan 5, 2017

I'd have the 3.5 if, and only if it was a high compression, and I'd put a carb on it. If you have to have the 3.9, then I'd still stay with a carb, as I hate electronics (!) - and, yes, the fuel consumption would be worse, but reliability would be better.

I'd fit a bigger than standard cooler to the auto too - it'll live longer.

DaveW · Jan 5, 2017

My only experience is with 3.9 efi hot wire and all I can say is that the power is great I get 24 - 26 mpg on a good day and it is cracking when you put your foot on the loud pedal!!

I must admit when I got it I replaced all of the efi sensors plus spark plugs etc and on a diagnostics is showed it ran really well with lower co2's then an 08 corsa!!

That is my experience only so I would go with what others say who definitely have more experience then me!!

I would also go for the auto box as I love them and definitely get a bigger cooler as suggested

boycie · Jan 6, 2017

3.9 with the hot wire or Mega squirt system .

ciderman · Jan 10, 2017

What is " hot wire" EFI?

cooltide · Jan 13, 2017

ciderman said:
What is " hot wire" EFI?

Electronic fuel injection first used in the late eighties in the range rover classic and continued being used on the discovery after the rrc went out of production through the nineties until they changed to Thor.

ciderman · Jan 13, 2017

Sounds like the devil's work.................

Which v8 engine would you have 3.5 or 3.9

dio99

New Member

jamesmartin

Well-Known Member

cooltide

sheep fancier

discool

Well-Known Member

Disco1BFG

Well-Known Member

DaveW

Member

boycie

Active Member

ciderman

Active Member

cooltide

sheep fancier

ciderman

Active Member

Similar threads