Hi guys, probably a question that's been asked many times before but anyway here goes.
Currently my 90 is running a 3.5 EFI.
I will at some stage be looking to upgrade the engine.
which V8 is best to go for? open to all options.
I know you can get LS kits but they're quite pricey, would a 4.0-4.6 lump from the P38 RR drop in easy enough?
and also which ones best for forced induction i.e Supercharging at a later stage too.
Thanks
Scott
This is a really interesting question.
The main answer is – what’s your budget!
Followed by – what do you actually want to achieve.
With big power, comes the potential for big borkage!!!
The 3.5 lump is ok and yes many claim it to be the most stout Rover V8 variant. But there is no denying you simply won’t extract the same performance from it, certainly not naturally aspirated. And by the same measure, there are many many 1000’s of larger displacement RV8’s out there across the globe.
By far the easiest and cheapest route would be to buy a 4.0 or 4.6 RV8 stick a cam in it and add some good breathing mods. It’ll mostly fit, but will likely require some changes. The other year I swapped out a cammed 3.5 for a late 3.9 serpentine in my TR7 V8. Despite the 3.9 technically making less PEAK hp over the cammed 3.5, the extra torque it makes across the rev range makes it feel far more powerful.
You’ll get a genuine 200-240hp potential, which in a 90 is likely more than enough.
As for forced induction. All of the supercharger kits are expensive tbh. And likely to cost in the same realm as an actual engine swap. Blowers work quite well with moderate CR levels, so almost any RV8 will be fine with them. The internals of the motor are more likely your limiting factor.
Have you considered a turbo setup? Might be worth investigating rear mount turbo setups. Quite popular in the USA. Much more home build friendly as you don’t need custom manifolds for the turbos. In the UK the lack of suitable large single turbo’s is likely to be your biggest hurdle. And with any FI setup you’ll probably want a more tuneable EFI setup.
Turbo setups will generally like lower CR levels. But a low boost system will work perfectly fine with the stock CR of most RV8’s. Really depends how far you are wanting to go powerwise.
Not sure what gearbox you are running, most will be fine with n/a RV8 power levels. But if you start going BIG power, expect to have lots of drivetrain problems to solve too.
In terms of engine swaps.
The Chevy LS is an option as is the older classic Chevy 350 series of engines. There are adapters to mate to Rover gearboxes, or to use a GM auto box and mate to the Rover LT230. Lots of fab work will be involved. But it’s quite a doable conversion.
The Lexus 4.0 V8 has also been used, but you may have to investigate a custom bellhousing adapter. Just as much fab work as the LS engine option, the big difference is the Lexus lump is usually a lot cheaper to buy.
Ford modular V8. The current 5.0 in the Mustang mates to the 6 speed gearbox in a Puma Defender. I think the older 4.6 and 5.4 variants of this engine might too. But these engines are even rarer than LS lumps in the UK. Again lots of fab work.
Jaguar AJV8. Big project, but you could look at fitting a Jag V8. Two ways of doing this. JE Engineering mate these to the 6 speed manual from a Disco 3. But you’ll need to fab up a flywheel and some other bits. As well as get the engine running. Or you could look at lifting the entire driveline from a D3 or similar. But lots of work I suspect.
