Best rebuild spec for a 4.0 Rover v8?

[RobXjcoupe]

Without going for extra cc, what would be a good spec to re-build a 4.0 Rover v8 engine?
It will be fitted to a Range Rover classic auto but I think the TVR guys will have a perfect spec
No turbo or supercharging just n/a please

[blitzracing]

Not really a TVR spec on 2 tonne car with an auto box, its all wrong. At its simplest look at a higher lift cam but with a short duration to maintain the low end torque= something like the viper hurricane that will bolt straight in.

[RobXjcoupe]

Thank you for a reply.
I appreciate an auto Range Rover isn't a TVR. It's just the TVR v8 builders seem a little more inventive with the possible mods and engine building side of things.
So just re-build a factory engine with a cam and timing gear. Imagine if a Rover v8 TVR was so simple
No worries was just curious

[Boosted LS1]

You could fit a chevy 6.2 with a gems conversion? That ought to haul ass ;-)

[RobXjcoupe]

That did cross my mind, a home made overfinch conversion. Originals are expensive to buy

[phazed]

Ideally.

4.6 engine for the additional torque.
4.0 pistons for higher comp.
Typhoon cam
72mm plenum
Decent induction
A pair of 421 manifolds and a decaf.

Give you 275bhp and close to 300 torque.

Add some nice heads and you'll see 300bhp.

Maybe a diy MS to run it all but not essential.

[RobXjcoupe]

phazed said:

Ideally.

4.6 engine for the additional torque.
4.0 pistons for higher comp.
Typhoon cam
72mm plenum
Decent induction
A pair of 421 manifolds and a decaf.

Give you 275bhp and close to 300 torque.

Add some nice heads and you'll see 300bhp.

Maybe a diy MS to run it all but not essential.

Hey now we are talking. I'm on a 92 j reg so no cat restrictions to worry about.
Thank you.

[OleVix]

phazed said:

Ideally.

4.6 engine for the additional torque.
4.0 pistons for higher comp.
Typhoon cam
72mm plenum
Decent induction
A pair of 421 manifolds and a decaf.

Give you 275bhp and close to 300 torque.

Add some nice heads and you'll see 300bhp.

Maybe a diy MS to run it all but not essential.

My choice also, not much more expensive than a 3.9/4.0 rebuild

[Squirrelofwoe]

OleVix said:

phazed said:

Ideally.

4.6 engine for the additional torque.
4.0 pistons for higher comp.
Typhoon cam
72mm plenum
Decent induction
A pair of 421 manifolds and a decaf.

Give you 275bhp and close to 300 torque.

Add some nice heads and you'll see 300bhp.

Maybe a diy MS to run it all but not essential.

My choice also, not much more expensive than a 3.9/4.0 rebuild

Purely out of interest, what kind of cost would that sort of upgrade run to from a TVR point of view? £8-9K ish? (presumably a chunk less depending on level of DIY).

[Brummmie]

You just need the 4.6 Crank/rods and use the 4.0 pistons, this was the engine that Peter originally inherited from me in a round about way.

[DonkeyApple]

RobXjcoupe said:

Without going for extra cc, what would be a good spec to re-build a 4.0 Rover v8 engine?
It will be fitted to a Range Rover classic auto but I think the TVR guys will have a perfect spec
No turbo or supercharging just n/a please

If you want your RR to go slower than before then fit a TVR engine.

You've a two tonne lump being powered via a 4 speed slush pump with a lock-up set at 50mph and an operating RPM range of 2,300 to 3,500 for almost all your driving. The standard cam delivers the torque where it is needed and how. Start moving the torque curve up or down and start trading torque for BHP and your massive lump of metal will get slower.

A 3.5 EFi RR will out drag a RR with a 4.0 TVR lump. And will ps off the bloke who just wasted ££££s

You can eek a bit more power by ditching the old electrics etc. But for anything significant you need to drop in a 4.6 set up to P38 spec or a super charger.

[RobXjcoupe]

DonkeyApple said:

RobXjcoupe said:

Without going for extra cc, what would be a good spec to re-build a 4.0 Rover v8 engine?
It will be fitted to a Range Rover classic auto but I think the TVR guys will have a perfect spec
No turbo or supercharging just n/a please

If you want your RR to go slower than before then fit a TVR engine.

You've a two tonne lump being powered via a 4 speed slush pump with a lock-up set at 50mph and an operating RPM range of 2,300 to 3,500 for almost all your driving. The standard cam delivers the torque where it is needed and how. Start moving the torque curve up or down and start trading torque for BHP and your massive lump of metal will get slower.

A 3.5 EFi RR will out drag a RR with a 4.0 TVR lump. And will ps off the bloke who just wasted ££££s

You can eek a bit more power by ditching the old electrics etc. But for anything significant you need to drop in a 4.6 set up to P38 spec or a super charger.

So to keep a 4.0 and a bit more grunt a supercharger is best or a standard build 4.6 from a p38?
I like the auto slush box rather than a manual conversion and I never even considered where the engine torque should be for the auto to work best.
So a fresh standard 4.6 is really best then?

[phazed]

A 4.6 drives that much better than the 4.0, agreed.

If you are starting from scratch I still reckon that the specification I gave above would drive very well and certainly quicker.

I had this in my Chim and it had plenty of mid range and would rev nicely if necessary.

I have had a few 4.0 Discoverys and they were smooth but fairly gutless.

What you need in your Range Rover is my 5.5.

[RobXjcoupe]

phazed said:

A 4.6 drives that much better than the 4.0, agreed.

If you are starting from scratch I still reckon that the specification I gave above would drive very well and certainly quicker.

I had this in my Chim and it had plenty of mid range and would rev nicely if necessary.

I have had a few 4.0 Discoverys and they were smooth but fairly gutless.

What you need in your Range Rover is my 5.5.

Your spec sounded good I thought for a 4.6. Easily obtainable parts, not too frightening trying to explain to insurance and relativly standard looking when looking under the bonnet.
Would solid lifters and adjustable pushrods be required for the cam you mentioned and would standard 4.6 rods and crank be ok to use?

[DonkeyApple]

RobXjcoupe said:

So to keep a 4.0 and a bit more grunt a supercharger is best or a standard build 4.6 from a p38?
I like the auto slush box rather than a manual conversion and I never even considered where the engine torque should be for the auto to work best.
So a fresh standard 4.6 is really best then?

Pretty much.

I've just built a 4.0 up for one of mine. It's in standard form as that deliverers the power in the right place for the old ZF slush pump and then I'm adding a Rotrex charger as my calculation is that it will deliver more power than a 4.6 or 5.0 NA unit but with better fuel consumption as it should be much more efficient during normal pottering. It's also much better on the drivetrain as it delivers power more akin to a turbo but I've still updated the internals of the ZF box to the later P38 ones as the HP22 really wouldn't survive long.

With a boggo 4.6 as long as you aren't Robbie Burnsying it all day long the HP22 should be fine as should the Borg Warner TC behind it. Plus you shouldn't be snapping drive shafts either.

[phazed]

Standard rods, pistons and crank are fine.

Good OE hydraulic lifters are absolutely fine as well.

I did about 40 TDs and some drag days with that set up and then the engine went in Dereks, (DangerousDereks) car.

[Brummmie]

phazed said:

Standard rods, pistons and crank are fine.

Good OE hydraulic lifters are absolutely fine as well.

I did about 40 TDs and some drag days with that set up and then the engine went in Dereks, (DangerousDereks) car.

I put bigger inlet valves and blended the throats on that too, i also shimmed the posts to get a decent average on the hydraulic tappets.

[RobXjcoupe]

Cheers guys for the valuable input. So at the mo, a mild tune 4.6 seems to be the flavour as it gives a bit more urge but I get to keep my standard running gear without any issues.
My original 3.9 block would be redundant. Can my 3.9 heads be used on the later 4.0/4.6 block together with the 3.9 injection system and then a re-map?

[Boosted LS1]

You can also fit a single turbo. The advantage is that you can flow more air then a Rotrex, should you want to. I know a man with a nice new manifold :-)

[DonkeyApple]

Boosted LS1 said:

You can also fit a single turbo. The advantage is that you can flow more air then a Rotrex, should you want to. I know a man with a nice new manifold :-)

People swerve the turbo route traditionally because of the cost of the bespoke manifolds and the rarity of the old Janspeed ones from the early 80s.

Do you mind me asking what the new solution is for Rangies?