Thread: 3.9 to 5.0 litre

Did not the 3.9 have more problems than the 4.6? I seem to recall it did.

Well not as far as I have heard, even though they have the same structural problems, and it's mainly because of the installation.
RRCs and D1s have an 88C thermostat and a humungous cross flow radiator.
38As had a 95C thermostat in a different position and a smaller radiator set too low. In addition a high percentage overheated due to radiator hoses bursting. I was present when one went once.

Des Hammill in How to Power Tune Rover V8s estimates that 25% of all 3.9 and 4.2 litres crack and 80% of 4.0litre blocks. 4.6 estimate is 15%.
I am a bit sceptical about whether the rebuilders who install the flanged sleeves do it properly. Hammill describes the procedure used by Wildcat and it is quite time consuming, involving sealant at the bottom of the sleeves to ensure no water gets out at the bottom, then a further final press.
3.9s (and 3.5) also have the problem of bearing cap shuffle, and Hammill recommends buying a new 4.6 as the safest option. BUT who is building new 4.6s now? Are they using the top quality blocks or just any block. RPi is now saying that the flanged liners are not a long term answer and that only the new Cotsworth engines are any good.

I would hate to spend 5K on a new 4.6 and have it die from a slipped sleeve.
Regards Philip A

Originally Posted by PhilipA

Well not as far as I have heard, even though they have the same structural problems, and it's mainly because of the installation.
RRCs and D1s have an 88C thermostat and a humungous cross flow radiator.
38As had a 95C thermostat in a different position and a smaller radiator set too low. In addition a high percentage overheated due to radiator hoses bursting. I was present when one went once.

Des Hammill in How to Power Tune Rover V8s estimates that 25% of all 3.9 and 4.2 litres crack and 80% of 4.0litre blocks. 4.6 estimate is 15%.
I am a bit sceptical about whether the rebuilders who install the flanged sleeves do it properly. Hammill describes the procedure used by Wildcat and it is quite time consuming, involving sealant at the bottom of the sleeves to ensure no water gets out at the bottom, then a further final press.
3.9s (and 3.5) also have the problem of bearing cap shuffle, and Hammill recommends buying a new 4.6 as the safest option. BUT who is building new 4.6s now? Are they using the top quality blocks or just any block. RPi is now saying that the flanged liners are not a long term answer and that only the new Cotsworth engines are any good.

I would hate to spend 5K on a new 4.6 and have it die from a slipped sleeve.
Regards Philip A

it would be cool if they redid the 4.6 core patterns to the 3.5 bore spec and just realised that forced induction was the go. ****, they did it with stupid diesels, but not the 3.5. oh well.

A blown / turbo'd 3.5.. ,

4.6 block @ 3.5 bore = no cap problems, no cam wear problems, good oil pump, proven long lasting strong designed block, no probs with slipped liners.

The 3.5 should never have been taken above na 3.5... stupid rover

it would be cool if they redid the 4.6 core patterns to the 3.5 bore spe

They did in 1995 for the British army and ALL suffered from slipped liners because of the way they did it.
BUT yes it would be a good idea.
A cross bolted 3.5 with 2 Subie turbos would go well .
The British motor industry seems to have a talent for snatching defeat from victory, something like our soccer team.

Regards Philip A

Once I get a definitive answer on the ZF boxes in the D1 (still want to put a ZF6HP28E in mine) then the puffer off of the jag will go on - as it is a straight bolt up but need to work out the problem of needing a stronger gear box

Originally Posted by rovercare

4L80E, don't think you'd need 6 ratios....plus the 4L80 adaptor is available to LT230

Advocates of the Rover V8 must remember, just because they did it (i.e fitted 4.6), doesn't mean they have too knock the alternative options, why poo poo something you obviously know **** all about, have never tried?? I love for an answer

Rover V8 heads can NOT support large capacites effeciently, so your scrwed from there, the last LS1 GU patrol I wired, has a baby camshaft, valve springs 3" single exhaust and a Mafless tune, it made 260HP on 35" tyres, and will return 15-16L/100, let me see your aftermarket ECUd rover stroker do that on 36's

Why convert? stock engine, with a substantial power incease, an ECU with closed loop, timing control, transmission control and you can plug it in at any holden/efi live/LS1 edit tuner

I'm not poo pooing the idea but fitting an LS1 into a disco is more than an engine change isn't it,to make it a reliable converson involves lots of electrics,two stronger diffs with axles,bigger brakes,exhaust,welding and cutting and a engineers certificate not to mention patience and more money than the vehicle will ever be worth.I'm a realist,not a dreamer. Pat

Originally Posted by PhilipA

They did in 1995 for the British army and ALL suffered from slipped liners because of the way they did it.

Originally Posted by PhilipA

BUT yes it would be a good idea.
A cross bolted 3.5 with 2 Subie turbos would go well .
The British motor industry seems to have a talent for snatching defeat from victory, something like our soccer team.

Regards Philip A

what's that saying....

"if you want to see something stupid, give a POM a piece of metal...... and ask them to make something with it"

They did in 1995 for the British army and ALL suffered from slipped liners because of the way they did it.

What did they do different from the usual 3.5 method?

Cheers

When you think about it logically, how much power does an engine require to drive a LR or RR effectively?

I know some people want 500HP or 1000HP at the wheels which in reality is stupidity gone mad. What ever for???????????

Driving along a freeway in Australia, unless in the N.T, speed is pegged typically at 100kph. To maintain this speed on level road in a normal family sized car requires from memory 40HP or there abouts. So a little bit more in a LR or RR.

Torque is what is really important, much more so that outright HP, so how much is necessary? The standard factory 4.6 produced in the order of 400Nm, and with a different cam such as a high torque edition the torque will come in sooner and improve low and mid range pull.

A 5.7 or 6 litre Chev will deliver more torque, but is it really a benefit? A Range Rover already can go where most would rather not take it, so what will be the advantage? Pushing through sand at a higher speed for example with a full load will only overload the drivetrain resulting in increased wear and reduced longevity...and more cost.

Ron.

Originally Posted by PAT303

I'm not poo pooing the idea but fitting an LS1 into a disco is more than an engine change isn't it,to make it a reliable converson involves lots of electrics,two stronger diffs with axles,bigger brakes,exhaust,welding and cutting and a engineers certificate not to mention patience and more money than the vehicle will ever be worth.I'm a realist,not a dreamer. Pat

Realist or slack? I'm a doer, making peoples dreams come true

Pretty much the same things required as a tyre upgrade except lots of electronics? 4 relays, 6 fuses and the standard ECU harness I wouldn't say alot

Your very correct, its more than an engine change for a good result, but its the same as upgrading the HP on a rover motor, the rest of the rover bits won't handle large HP and abuse

And yes it can get expensive, if you have to pay someone to do the work, but the poor man pays twice, I've paid twice many times, I had a supercharged 3.9, it was nice and driveable, but nothing on a LS1