4.6 into a 3.9 classic?
Discussion
Above is a picture of my old Range Rover 3.9
Basically I would like to upgrade her engine to a 4.6 version.
Without going into the internal spec of the engine, will things bolt up to the older 3.9 mounts together with all the peripherals, power steering etc?
Also will the 3.9 injection and management system fit the 4.6 with an uprated ecu?
Apologies for lack of detail as I'm learning and making notes before I start taking things apart
Thank you in advance for any info
Cheers
Rob
Yes, is the short answer.
I run a 4.6 in my 4 door classic with the original mounts/timing cover/inlet manifold and a re-chipped ECU.
I am running a different cam shaft and cylinder heads but standard items do fit.
You will need a space for the crank shaft to engine pulley, you can either buy one or just machine one up.
I run a 4.6 in my 4 door classic with the original mounts/timing cover/inlet manifold and a re-chipped ECU.
I am running a different cam shaft and cylinder heads but standard items do fit.
You will need a space for the crank shaft to engine pulley, you can either buy one or just machine one up.
task said:
Yes, is the short answer.
I run a 4.6 in my 4 door classic with the original mounts/timing cover/inlet manifold and a re-chipped ECU.
I am running a different cam shaft and cylinder heads but standard items do fit.
You will need a space for the crank shaft to engine pulley, you can either buy one or just machine one up.
Can the original injection system work with one of the Thor type inlet manifolds from the later 4.6?I run a 4.6 in my 4 door classic with the original mounts/timing cover/inlet manifold and a re-chipped ECU.
I am running a different cam shaft and cylinder heads but standard items do fit.
You will need a space for the crank shaft to engine pulley, you can either buy one or just machine one up.
RobXjcoupe said:
Can the original injection system work with one of the Thor type inlet manifolds from the later 4.6?
No, to use THOR inlet you either need megasquirt or the THOR ECU re-chipped to run stand-alone. The major benefit to either THOR ECU or megasquirt is spark management, however this involves far more wiring and a greater cost. It is possible to run the 4.6 on hotwire using a non-chipped ECU but to release the full potential a re-chip will be required.With regards cracked blocks and slipped liners, you won't always know just by looking. Some are very apparent in their failings but others can look fine but still fail a pressure test.
I've had both my 4.6 blocks top-hatted as part of the process, if you get your block top-hatted it would be worth getting the whole rotating assembly balanced (it's worth doing this even if you don't liner the block) as the crank damper on the 3.9 will be balanced differently to that of the 4.6.
If you were closer I'd have said pop round for a cuppa and a poke round my 4.6 4 door
Number of reasons put forward including:
Poor machining of the block from new.
Overheating caused by poor maintenance of the marginal cooling system combined with the lean fuel mapping.
The 3.9/4.0 suffered from the same issue, but doesn't appear to be to the extent of the 4.6.
AIUI the original 3.5 (mine!) is pretty bombproof.
Poor machining of the block from new.
Overheating caused by poor maintenance of the marginal cooling system combined with the lean fuel mapping.
The 3.9/4.0 suffered from the same issue, but doesn't appear to be to the extent of the 4.6.
AIUI the original 3.5 (mine!) is pretty bombproof.
I've been looking at the mega squirt kit and it fits the older 3.9 together with the Thor inlet manifold.
I might stick with my known engine, as it's been serviced well all its life and she runs fine but with the more upto date Thor inlet and coil pack ignition via mega squirt.
A 4.6 would be good if it's re-built as an overhaul rather than new top hat liners.
Anyone done a 3.9 with a Thor inlet and mega squirt kit?
I might stick with my known engine, as it's been serviced well all its life and she runs fine but with the more upto date Thor inlet and coil pack ignition via mega squirt.
A 4.6 would be good if it's re-built as an overhaul rather than new top hat liners.
Anyone done a 3.9 with a Thor inlet and mega squirt kit?
What you need is a 4.6 "strip" engine with a kent H180 long-nose cam and crank spacer - both available from Turner engineering - everything else will bolt on
As for your fuelling I strongly suggest you send the ecu to tornado systems for remap - tell Mark what size engine and gearbox you have and what cam - he will then fuel it accordingly
You will also need a bigger AFM and will need to advance the timing from 28 degrees to 32 at 3500 rpm with vacuum disconnected
To get the best out of it you will need a set of bosch injectors which Tornado also sell
You will also need to fit some long-pipe hedman exhaust manifolds as well otherwise you will not get the full benefit
As for your fuelling I strongly suggest you send the ecu to tornado systems for remap - tell Mark what size engine and gearbox you have and what cam - he will then fuel it accordingly
You will also need a bigger AFM and will need to advance the timing from 28 degrees to 32 at 3500 rpm with vacuum disconnected
To get the best out of it you will need a set of bosch injectors which Tornado also sell
You will also need to fit some long-pipe hedman exhaust manifolds as well otherwise you will not get the full benefit
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