Thread: 3.5 efi vs 3.9 efi

Hello Mild,

The 3.5 isn't really a stronger block rather the material that was between the liners on large capacity engines is thinner. There were a number of different castings over the years so a 3.5 is different to a 3.9 which is different to a 4.6 and so on.

In terms of block rigidity, the latter engines such as the 3.9 are stiffer. Retention of the main bearing caps is also better although in a standard there is nothing really wrong with the cap retention in a 3.5 either.

If I was going to buy a brand new engine with fuel injection, I guess the 3.5 would be the safest bet. If the engine was using a seasoned block fitted with top hat liners, then the 3.9 would be the one as there are no issues once the top hat liners have been fitted.

I take it that your current engine is a 3.9? The 3.5 has less power and torque, and likely will use more fuel given that it will be working harder. The best bet I feel is a seasoned block with top hat liners and the rest built on that.

Ron.

Ill make an assumption
The 93 Range Rover isn't a bush basher so i would be more inclined to get a reco 3.9
More power

T.R.Spares New, Reconditioned & Second Hand Spare Parts
and if i remember right they do the short motor reco for around 2200

I just upgraded the engine in my Discovery from 3.5 to 3.9 and its a huge difference

yeah, a 3.9 which was fully rebuilt 10000km ago but was diagnosed 4500km ago as having a slipped liner. I still have to prove it when I take the heads off though. having the block top hat lined sounds expensive but I'd have a nice motor The 3.5 efi would be a cheap quick alternative. Are any of the parts from the 3.9 compatible with the 3.5? mmmmm.

Almost everything that bolts on the outside of the motor is the same
The most obvious difference is the timing cover serpentine or non serpentine

Steve, I was actually sort of turning it in to a bush basher, just a weekend vehicle/camping. I now think I should have bought an early 2 door, without much of the prince of darkness that I've heard so much about lol.

see, even If I could get that one liner pinned just by taking the sump off maybe? It could have a cracked liner though. But as someone said once before, you would get the lot done. But full removal of motor/strip would have to be done

I don't know if that's possible

If the block is stuffed there's a couple of motors in the market section for sale just rebuild one of them

Definitly some food for thought, thanks