Hi,
Have looked for the best response on search but to no avail....
I have a 1991 defender 90 soft top in great condition but with a poorly 200tdi engine , the funeral is soon..... I have decided to play and pimp it up so I would like some advice on the best V8 engine that I could drop into it . Will the existing gearbox work with it or do I need one of these too ?
Thank you in advance for your responses including the sarcastic ones that are bound to follow lol.
Some simple things to cover first.
-Do you have a budget in mind?
-Does it need to stay Rover, i.e. do you compete with the ALRC?
-What other upgrades would you consider?
For the record, the Tdi is a good power plant for 120-150hp aims with plenty of torque. And a tweaked Tdi will feel a lot more pokey than what you think it should be for it's hp level.
The easiest swap in will be a Rover V8. It'll basically bolt right up, although factory V8's did use some different parts, but you can basically do this without having to customise or fabricate much.
Rover V8's come in many different shapes and sizes... The 3.5 is common still. But tbh, any performance gains will be minimal. Low CR 3.5's used in Land Rovers, Range Rover's and the MGB GT make 120-135hp when fresh.
These will run similar performance to a tweaked Tdi, but with worse mpg.
3.9's are plentiful and much better bet, most are high CR and the extra displacement means you have 180hp+. A good one of these will go better than pretty much any Tdi, no matter the state of tune.
Fitting a stock'ish 3.9 is an easy cheap way. These motors can be had for about £300 and with a few simple mods can see circa 200hp.
The 4.0 is basically a 3.9, just from a later vehicle.
Then there is the 4.6
Sadly 4.6's and most latter RV8's are known for slipped liners. But I wouldn't let this stop you. As I'm sure there are plenty out there with no issues at all.
But it all comes down to how much power vs money you want to spend.
The reality is, an RV8 is a good engine for 180-220hp. But if you want to get more power than this, then you could end up spending big time. And even with a huge budget they will never be horse power monsters.
Once you start with high lift cams, ported heads and all the other bits, you'll just keep adding £££, or less and less return.
But the RV8 is still a good bolt in option. And of course if you feel adventurous, you could look at power adders such as supercharging, turbocharging or nitrous oxide. But you can easily add plenty of money this way.
The next obvious candidates are the GM, aka "Chevy" V8's. These come in two main flavours, the classic cast iron 350 engine. And the new in 1997 346ci LS1 that replaced the 350. Personally I'd avoid the older 350 (they are both 5.7 litres BTW), as it's heavier, makes less power than the LS1 and won't really save you any money.
A stock LS1 5.7 will make about 350hp and 370ft lb, which is generally more than even full on race spec 5.2 Rover V8's that might have cost £10k to build.
Buying a used LS1 in the UK isn't the easiest thing, but they do crop up and there are places that will ship them from the USA.
Fitting these, you have two main options.
Keep the LT230 and Rover gearbox, or keep the LT230 and use a GM gearbox. Either way will require an adapter kit.
There is a kit that allows you to mate to the LS1 to the LT-77/R380 Rover 5 speed manual. This seems to be something that happens in Oz quite a bit. Technically the LS1 is way above the rated limit for these gearboxes, but it must work else why would an adapter exist. Just don't expect an LT-77 to last forever though, even less if yo are brutal with it.
In principle the LS1 swap seems like it could be fairly simple. At least in as far as major engine swaps go.
Other options you could look at. The current Ford Mustang 5.0 DOHC. This should bolt directly onto the 6 speed found in Puma (2.2/2.4) Defenders. Which means it's easy to retain the LT230. But I suspect one of these engines will cost more than an LS1 to buy, but would give you a stouter manual transmission setup. If going auto, then there is no real advantage.
Other options would be the Jaguar AJ-V8. These engines are cheap and easy to find in the UK, so a big plus. Downside is, they use a lot of electronics. You could simply have a go at swapping an entire driveline from a Disco3/RRS, but that sounds like a lot of work.
JE Engineering offer some V8 manual Defenders with this engine, they use the ZF 6 speed manual from a TDV6 Disco3, but you'll have to figure out how to make this work. You'll need some kind of adapter most likely to mate and some sort of flywheel.
There are also companies that use the Jag V8's with the 6 speed box used in the Defender (this box is also used in the Mustang and other vehicles). But again you'd need to research how to make this work.
And of course, if you fancy more R&D there are loads of other options. The BMW 4.4 as used in the early L322 Range Rovers and the Lexus 4.0 V8 would seem good candidates, as they are cheap and easy to buy in the UK.
