RV8 Conversion.

[Tony Jones]

Hi all,

As this is the place that evryone has basically done evrything possible to Land Rovers I thopught i'd ask you all whether anyone has any hints, tips etc on a V8 conversion to my Airportable.

What I want to do is as follows, I thought about getting the Ashcroft Hi Ratio Transfer box, adapter to fit a rebuilt LT85 gearbox from an '89 Range Rover (after its been rebuilt) and fit a rebuilt 4 litre V8 from a 3.5 litre lattice block. The engine will obviously have to be overbored to fit new cylinder liners, I have a new 71mm crank already, the heads I want to get are Stage 2's, I want to fit a hi torque cam kit, edelbrock inlet manifold with either a Holley or Edelbrock 4v carb with electric choke, modified Range Rover headers and custom twin exhasut in either 2.5/3" bore. The engine should be putting out about 260 and equal torque more importantly.

I will obviously have to uprate the running gear extensively, I intend to fit LSD front and rear, uprated half shafts etc. The suspension will be changed for +1.5 "/2" Parabolics and if possibly 1 ton Shackles although I hear I may have to modify the front mounts a little to make them even. I intend to put a set of 285x65x20's on her via adapters and some light machining which are about 35" diameter I believe. The diffs will be the 4.75:1 ratio, will this be correct to keep decent acceleration with the rest of the gearing?

I also intend to try a PAS conversion using the RR or Defender 4 bolt box etc.

Also i wonder if I could go past the 4 litre of is that going to be the maximum that the running gear can take? Ideally I would love to do a full 4.8/5 litre conversion but I reckon the 4 litre high torque engine will be probably all I can go with the mechanics of the running gear.

What do you guys reckon? This is going to be a long term project obviously but is worth doing I think? All hints, tips, info, comments will be appreciated guys.

[Jon White]

Sigh............dont try to run before you can walk!

Right........

LT85 will put the gear lever somewhere in the vicinity of the middle of the seat box, and will push the transfer box back so far you'll have propshaft clearance problems. IMHO you'd be better off fitting an defender LT77 with a 4 pot bellhousing and an adaptor plate as the whole lot is several inches shorter. You'd also be better off fitting the LT230 too than the archaic series transfer box. LT85 was never fitted to range rovers by the way - that'd be the LT77 which is unsuitable as the gear lever is even further back!

Whilst you can fit uprated diffs and ring and pinions, series uprated halfshafts are not easily available. They can be imported from the states or Aus at (very) great expense but arent easily available. Anything more than a standard 3.5 on carbs and you're into problems with drive train strength (been there done that!)

Also think about how the hell you're going to keep things cool! Theres not alot of room in the front of a lightweight for bigger rads!

Finally do not even consider fitting either of those carbs to your engine. They are both awful things that do not like running at angles etc, or cause misfiring when cornering at speeds even if you do fit the "off road" kits to them!I wouldnt consider fitting anythig othe than efi to an engine with that spec. Otherwise if you simply stick to a standard 3.5 the standard twin su's or strombergs are good if in good condition and well adjsuted.

HTH

Jon

[Jon White]

And another thing.............brakes!!!! Standard drums are barely up to stopping the standard vehicle! You need to think about disks all round IMHO!

Also clutch - you'll need a paddle clutch to put that sort of power down!

Cheers

Jon

[zim]

make a normal hot rod instead

then spend a little bit of money on a 3.5 v8 with conversion plate, lt77 or R380, and stick it into your series.

and this is how your gearsticks will approximately be :

3.5's can be driven on series axels, the bigger drum brakes make it a bit nicer, but still the stopping power is nothing like discs !

or if you fancy a bit more power the 4.6 v8 is the same physical size.

[andyb]

Ask you question here http://www.lightweightlandroverclub.org/phpbb/index.php

There is even a V8 Lightweight section and a user with the name "4.6v8lwt" .....guess what he has done

[FridgeFreezer]

Welcome Tony, you've got some big plans and presumably some big money to go with - let's see if we can save you a lot of time and maybe some money here...

What I want to do is as follows, I thought about getting the Ashcroft Hi Ratio Transfer box, adapter to fit a rebuilt LT85 gearbox from an '89 Range Rover

As Jon says, the early Range Rover were LT95 which is a big horrible beastie (albeit quite a strong one) with integrated transfer box, the later ones were LT77 which is 5-speed and up to most things, followed by R380 which is a little better. If you're going to the hassle of adapters, just forget about the Series transfer box and use an LT230, they're available in a variety of ratios and are designed for the 3.54:1 diffs which means you can use those and still have the correct gearing on & off-road.

You need to note that Range Rover & Disco gearboxes will all have a long (~30cm) bellhousing and the gear lever at the back of the box, which puts it somewhere in the middle of the centre seat. A defender gearbox (again, could be LT85, LT77, R380) will have the gearstick nearer the front by about 30cm although there were no V8 defenders with the LT77/R380 that I'm aware of. (I could be wrong and there could be a few short V8 LT77's out there?)

(after its been rebuilt) and fit a rebuilt 4 litre V8 from a 3.5 litre lattice block. The engine will obviously have to be overbored to fit new cylinder liners, I have a new 71mm crank already, the heads I want to get are Stage 2's, I want to fit a hi torque cam kit,

Woah there neddy! That's a pile of cash in engine bits, and frankly these days the Rover V8 isn't worth it. A well-done rebuild with a couple of nice bits is about as far as it's worth going. If you need bigger/better, buy a bigger lump (a 4.2 from an LSE Range Rover or a 4.0 or 4.6 from a later P38). Beyond that, just buy a more modern engine - L67 or LS1's are super cheap horsepower, or in a small, light vehicle a modern 4-pot or V6 will give as much power & torque as the Rover V8 but with double the MPG.

edelbrock inlet manifold with either a Holley or Edelbrock 4v carb with electric choke

Nooooooooooooooooooooooooooooooooooo!

I've had both those carbs, properly set up, and they were hopeless. Neither of them likes off-roading (even with the off-road modifications) and you may as well point the fuel hose directly down the inlet than fit the Weber.

I know I'm always saying this, but for the price of either of those monstrosities you could fit MegaSquirt'n'EDIS EFI, lose the distributor and have loads more power and driveability. And be able to drive through a puddle or up a slope without coughing to a halt.

The engine should be putting out about 260 and equal torque more importantly.

No it won't. Sorry, but no it won't. You can't play the game of adding up all the theoretical BHP gains for various mods, adding the factory pwoer figures and coming up with a big number. Have a read of Ian's V8 build in the technical archive, and have a peek at his dyno results. Especially if you insist on using carbs you'll be nowhere near.

I've been told by "experts" my 4.6 should be putting out close to 300bhp, but I'd be quite surprised if it's much more than 250 (~25 up on what the factory claim) on a good day.

I will obviously have to uprate the running gear extensively, I intend to fit LSD front and rear,

I'd have a read up on that first, there are issues around putting clever diffs in the front axle, especially on short vehicles. I can't remember the details, but have a read before you do. In fact, before you start uprating Rover axles, have a look round at Japanese ones - they are stronger as standard and often come with LSD's or lockers. Complete sets can be picked up for less than the price of a Rover LSD.

Oh yes - BRAKES! Even the big V8/6cyl drums are not really enough to stop a lively 3.5 V8. Fitting discs is either a very involved project (have a search, people have done it very nicely) or a very expensive prospect. The easiest way is really to swap the axles completely, although you can then run into different issues. Again, a search will reveal all you need to know. Look for posts by Meccano and Gremlin.

The suspension will be changed for +1.5 "/2" Parabolics

Why? Unless you need the lift for some technical reason, I'd stick with standard height and avoid the issues a lift brings.

I intend to put a set of 285x65x20's on her via adapters

20" For the love of God, why? It's going to look really weird. You can buy "normal" 34"/35" tyres for a 15 or 16" rim easily enough and have much more choice.

The diffs will be the 4.75:1 ratio, will this be correct to keep decent acceleration with the rest of the gearing?

Not with 35" tyres and a hi-ratio Series transfer box, no. You probably need an LT230. Have a look in the technical archive for "gear ratio calculator", you can do the maths there and compare your gearing with various standard vehicles.

I also intend to try a PAS conversion using the RR or Defender 4 bolt box etc.

Relatively easily done, assuming you can weld well enough to hold a major component on and have more than a rubbish hobbymig at your disposal.

Also i wonder if I could go past the 4 litre of is that going to be the maximum that the running gear can take?

A normal 3.5 is about all the running gear can take, depending on how you drive. It was designed for 62bhp, the 3.5 EFi is ~160 and the 3.9 is ~180 (factory figures, natch). In a Lightweight, even a 3.5 is a hoot. I'd see if you can drive someone's V8 Series before you decide you must have some super expensive engine.

Ideally I would love to do a full 4.8/5 litre conversion

As I said above, it's absolutely pointless spending that kind of money on a Rover 8 these days. $2000 buys you a 300-400bhp all aluminium yank V8 which can be tweaked way beyond 500 for peanuts and will run reliably and reasonably economically for 100,000 miles. Another $2000 buys a very strong gearbox to go behind it. A Rover V8 tweaked till it screams will maybe hit 300bhp but it will be neither cheap nor particularly flexible.

What do you guys reckon? This is going to be a long term project obviously but is worth doing I think?

Your spirit is admirable, however I think you need to either rein it in a bit and stick to something a bit more reasonable (sticking to a 3.5 or 3.9 EFi with LT77 and LT230 is going to cost you a fraction of what you've described, be loads less hassle to do, and give 95% of the fun factor), or go the whole hog and stick something proper in there with some real numbers and forget all this outmoded stuff about tuning the Rover V8.

Oh, and good luck, and keep us posted!

[Quagmire]

I would do as the others suggest, I am currently rebuilding a 3.5 to drop into my 2.25 90. One thing i would say is that you need to price up what you want to do and see if it is realistically affordable/ worth it.

My engine is going to be pretty much standard spec when its back together but just ensuring that everything is done to a good standard means that inevtibaly you end up spending more than you planned. Parts are cheap for the v8, but there are twice as many of them! Make sure you include money for a slight overspend in your budget.

Check www.v8forum.co.uk for engine stuff, there are quite a few landy owners that post.

[muddypaws]

I wish I had been the beneficiary of the good advice above before I started out with similar plans to you.

Rover V8 - the standard 3.5 or 3.9 is fine. Sounds lovely, bags of grunt and no real issues (aside from liners)

Edelbrock - got one, hate it changing it for EFi. Looks lovely, sounds lovely, drinks fuel and is a real bitch off road. Don't go there. Achieving MOT emissions compliance has been almost impossible.

Megasquirt - not got my head around it yet but certainly everyone I know talks favourably.

Brakes - discs are an absolute must. I have the Chris Perfect conversion on mine and they are great. Still careful though.

Tyres - there are better experts than me; most of them are forum members and I have never gone wrong listening to them.

Cooling - if you want to keep the Lightweight profile (and why shouldn't you, that's what makes the motor so nice), cooling is an issue. I have a small bonnet scoop on mine and I am in the process of working out how to fit the new style side vents of a Freelander 2 or Disco 3 etc into the sides of the bonnet as that will look cool and help to keep it cool. As with all things on a conversion, it takes lots of thinking and cups of tea. An unexpected side issue is the starter motor. Quite simply they cook in a Lightweight given the proximity of the downpipes. I have lagged the pipes with thermal shield, fitted a heat-guard from an MG RV8 and checked the timing (yes this significantly effects the heat of the engine) and the thermal cut-out/overload relay in the starter still causes embarrasment when you stop anywhere on even a mild day.

Gearbox - I have a standard box and transfer set-up from the original Lightweight (S3). Despite some aggression whilst trialling and general lack of smooth changes etc, I have yet to break either the box/transfer box or any half-shafts. Maybe I have been lucky !!! My plan is a 4HP22 auto-box through a standard series transfer box adapted to use the Ashcroft conversion kit (for the auto-box) and their higher-ratio transfer gears. Before I embark on that though, I need to do some real thinking around the propshaft lenghts and clearances. If I can make it work then I will be able to retain 2/4wd, I get the better cruise speed with lower revs and I don't have to spend ages trying to fit an RR/Disco front axle as you would otherwise to solve the CV problem. That is an absolute sod of a job IMHO; I really do take my hat off to those who have done it.

PAS - probably the easiest thing I have done. Lots of measuring, a new front cross-member, a FULL PAS kit from an RR, 90 steering column and a good welder. Makes all the world of difference to the motor. The MOT man was well-impressed. Be very careful about trial fit before you weld and chop. The final placement of the steering wheel within the cab depends on this and remember, it is really difficult to move the seat back any further.

Fuel Economy - Edelbrock is dire. EFI lots better.

Parabolics - essential.

Suspension lift - nah

Is it worth it; heck yes. I could have bought a 90. I should have bought a 90 but I LOVE my Lightweight. My peers and friends all run 90s or hybrids but there is nothing like a well sorted Series to make them all hanker after one and go aaah! Particularly a Lightweight

Good luck.

Happy to help at any time.

[landmannnn]

Tony,

Adding the advice given above....

Converting series vehicles with tuned rv8's was the state of the art during the 80's. We spent small fortunes....

In the nineties (maybe a bit earlier) we moved on to putting things on RR chassis. These were much better vehicles than the previous versions, cheaper as well.

In the noughties the defender models got cheap enough to become the platform for mods. Series vehicles are now becoming collectors favourites, unmolested of course.

In short, keep your lightweight standard. It may be slow etc but it's got character. If you want an off roader then get an old 90 to play with.

[MECCANO]

In short, keep your lightweight standard. It may be slow etc but it's got character. If you want an off roader then get an old 90 to play with.

I think that all depends on how much its been fiddled with. If its been messed with already, you might as well carry on... Oh and fit a diesel

[dave88sw]

there were a few late v8 defenders with lt77's (my dad has one so thats conclusive proof ). However finding a box from a v8 defender will be a pain (although im not certain that they're different to a standard tdi/td etc box?). As many have said though, that kind of power in a lightweight is never gonna be a simple task, you want to put all that power and torque through transmission that simply wasn't designed for it and is, by now, at least 25 years old. The brakes won't take it, the handling will be awful and overall it will be a major headache just fitting it. As many have said, a standard 3.5/3.9 is brilliant and has more than enough power for a series, however the more i look through the post, i start to wonder why you're planning to do this with a lightweight. If it's cos you like the look, i can't help but feel that its much easier to put lightweight body panels onto another vehicle (disco/rangie) which were designed with a v8 engine in mind.

There will probs be people who disagree with me there saying its a waste of 2 nice vehicles but as i see it, if you have a rangie with a rotten body and a lightweight with a rotten chassis, making a good vehicle out of the two is a good way to save both and turn them into a useable vehicle. (anyway thats a bit off topic)

good luck with whatever you decide but bare brakes in mind, afterall, its all very well making a landy go better, but if you cant stop it just as well, you're screwed and a runaway landy can do a LOT of damage.

[Tony Jones]

Thanks guys for the masses of very good advice, although to be honest I am disappointed at having all my dreams shattered in one fell swoop!!

Right, perhaps I should start at the beginning then. I have always loved the Lightweight but have always wanted to modify one extensively. When I started to rebuild that one it was a selection of bits scattered all over our property, mainly bits from series three models, very little of it is original. This is the bit where I get ostrisized (spelling?) from this club for saying this but she is being modified purely for aesthetic, she is a purely road going car and will not be being offroaded. The reason why I want the V8 so much is purely for the luscious symphony from the pipes, sounds beautiful, sorry, I hate the sound of diesels, especially in that machine.

The other problem is that Yank V8's aren't exactly plentiful over here in Northern Ireland otherwise i'd be looking at putting a modified 7 litre LS2 in her Further to this we have a problem with the new MoT rules coming into being about a points system

As for the gearbox, the main box has an aluminium casing and I was told that the LT77's were all iron casings so therefore it must be a LT85 box. At least that is what I was told. I do not doubt you guys only relaying the info I was given as I do not know myself. Same goes for the power figures for the 4 litre hi torque engine. The info came from Real Steel although looking back it was an EFI engine that was dyno'd. my mistake, although from what you guys say, it sounds too optimistic.

As for the LT T'Box + % spd boxes with the 88" wheelbase i am told that the rear prop is far too small and would cause problems on road let alone off road.

Brakes and clutch i forgot to mention, already read with great interest your highly detailed brake conversions, they are an absolute necessity of course aswell as a HD clutch, was thinking of a 10.5" McLeod piece.

EFI over carb, fair enough, I have an EFI 3.5 aswell so that could easily be the donor, a complete '89 RR Vogue EFI in fact.

Oh, the cooling was going to be via Defender V8 Rad + electric fans with the main part of the rad assembly cut out as the steering relay would no longer be in the way due to the PAS conversion.

Looks like i've got some rethinking to do then I want to keep the chassis ID as she is currently a 1969 model and therefore tax free here. Got lots more to rethink then. Thanks for the advice, any and all comments still appreciated!!

One other question though, what's a Megasquirt EFI??

[ThreeSheds]

Hi, Welcome to the forum, and well done for 'taking it like a man'!

It's not easy to have dreams shattered, but you did the right thing in posting here and thereby (from the sound of it - I am no expert ) saving yourself a world of cost and pain!

Anyway, to your last question:

One other question though, what's a Megasquirt EFI??

Have a look at this and search elsewhere in the forum. Briefly MegaSquirt is a fully customisable and robust, home built injection and ignition control system.

For a simpler - ignition only - conversion look for MegaJolt, but with this you will need to retain the Rover injection ECU.

IMHO, with these systems available and them being relatively cheap, there really is no excuse nowadays for anyone building a RV8 with a distributor...

Hope this helps.

Roger

[FridgeFreezer]

Gearbox - If I can make it work then I will be able to retain 2/4wd, I get the better cruise speed with lower revs and I don't have to spend ages trying to fit an RR/Disco front axle as you would otherwise to solve the CV problem. That is an absolute sod of a job IMHO; I really do take my hat off to those who have done it.

Beg to differ, you can make an LT230 2x4 quite easily, have a search, I've done a fairly idiot-proof post on the subject with pictures & biscuits There are also people who run the LT230 in 4x4 mode with the standard series UJ's and reported no issues. The third option is to use a Stage 1 V8 front axle which has CV's, you'd need to swap a diff to make the front & rear ratios match (the S1 V8 is 3.54:1 ratio) but that's no biggie.

[MECCANO]

I hate the sound of diesels, especially in that machine.

Prepare to be deeply upset

[Hybrid_From_Hell]

Dare I also mention SVA / C&U and Points system, with the plans you have you'll be the wrong side of legal

Nige

[muddypaws]

Beg to differ, you can make an LT230 2x4 quite easily, have a search, I've done a fairly idiot-proof post on the subject with pictures & biscuits There are also people who run the LT230 in 4x4 mode with the standard series UJ's and reported no issues. The third option is to use a Stage 1 V8 front axle which has CV's, you'd need to swap a diff to make the front & rear ratios match (the S1 V8 is 3.54:1 ratio) but that's no biggie.

FridgeFreezer, I did read your post and was very impressed however, it is beyond my mechanical and welding ability/confidence. No offence intended in my post just that the Ashcroft route is easier in some ways for a numpty like me.

[Tony Jones]

Prepare to be deeply upset

Do your worst!!

[FridgeFreezer]

it is beyond my mechanical and welding ability/confidence.

It was beyond mine when I started too

[MECCANO]

Do your worst!!

Oh i will

And i will be able to show you some dirty images in the coming weeks!!!

[Tony Jones]

Ooooeeer!!

Hold on, just realised something, you do all this fabulous work on your wagons and then get them dirty too!! You're all MAD!! Couldn't be doing that with my old girl, she's not that kind of girl!!

Besides, if I got a scratch on her i'd be crying my lamps out!!

[FridgeFreezer]

Dents and scratches are character, dear boy. A shiny Land Rover is the sign of a wasted life.

[Mark]

If it is only going to be a road toy, then why bother with drive to the front axle? You could solve most of your prop length problems by fitting a conventional gearbox, and forgetting about the transfer box altogether...

just a thought

Mark

[Tony Jones]

If it is only going to be a road toy, then why bother with drive to the front axle? You could solve most of your prop length problems by fitting a conventional gearbox, and forgetting about the transfer box altogether...

just a thought

Mark

That had occured to me but if I was going that far then could I remove the diff completely and halfshafts to save quite a bit of weight at the front and more importantly what happens at MoT time, am I likely to fail as a result of the missing prop etc?? That's my worry.

Fridgefreezer:

I knew i'd left myself somewhat open to some serious flak for that statement!! It is kinda the antithesis of Land Rover. Looking very good but is likely to go off road as an Irishman is to move away from living next to a Distillery I promise though, I will have to get something that I can do some offroading in to make up for it!!

[FridgeFreezer]

That had occured to me but if I was going that far then could I remove the diff completely and halfshafts to save quite a bit of weight at the front and more importantly what happens at MoT time, am I likely to fail as a result of the missing prop etc?? That's my worry.

The MOT doesn't test that, and there were 4x2 Land Rovers used as staff cars so you could argue it's been tried by Land Rover themselves.

If you just want a RWD hack-about, why stick with all this LR junk? Have a look at a BMW, Jag, or Volvo engine & box combo. The engines make more power & better MPG than most LR things, and a whole car with a bit of rust is likely to cost you peanuts.