Land Rover 3.9 V8 and manual gearbox

[Marco Polo]

Hi Guys,
I hope that I don't cause too much controversy here but I have been offered a free 3.9 V8 and gear box from a 1992 Land Rover Discovery by my brother in law. Has any one here carried out a similar conversion to their Stag. I'm thinking of putting it in my car and using the engine from my sons car and my Triumph manual gearbox plus O/D in his car and also having a spare TV8. Triumph spares are like rocking horse poo Down Under and my car isn't exactly original so a performance increase project could be what I need! Also what mods are recommended to the engine cams, head skim, fuel injection, ecu, rebore etc?

Thanks and regards,
Raoul

[V Mad]

Hi Raoul
Its all been said before, but an engine change is a major undertaking, but if you understandand what is involved and still want to go ahead, all the info is available if you search around. But unless you are going to make all the adapters etc yourself would you not have to import many conversion parts from UK? And the LR gearbox will be a 4x4 so not suitable for the stag.

[stagmuffin]

This type of conversion has been done before and im sure is well documented , but the engine is a dinosaur in in stag terms, is there nothing else available home grown that could challenge your enginering skills and maybe be more widely available .the new zealand guys seem to of cracked the lexus v8 some good projects there .
Steve

[73stagman]

As above its not the best swap!
My stag is a Saloon Rover V8 and gear box so for me there is no problem doing the swap but...
If you use the landrover setup, you will have to do a cam change on the engine and retune as you wont be lugging two tons of truck about in the Stag. you will also find with the gearbox...
1. it will have a huge bellhousing which wont be suitable for the Stag,
2. it will have a transfer box on the side which you will have to remove and find the right parts to fill up the hole that is left behind when the transfer box is removed.
3. Then to finish off the idea your gear ratios will be all wrong for the stag too.

The 3.9 EFI is a good swap if you feel the urge to do a swap (If you can find a SD1 3.5 Vittesse twin plenum then even better but they are seriously hard to come by even over here!) but either use an auto box or a later Heavy Duty manual gearbox (Later versions are better than the LT77)

[jakesmig]

This type of conversion has been done before and im sure is well documented , but the engine is a dinosaur in in stag terms, is there nothing else available home grown that could challenge your enginering skills and maybe be more widely available .the new zealand guys seem to of cracked the lexus v8 some good projects there .
Steve

The Stag I bought in 1978 had a TV8 engine in it, what memories, all bad. I've got a 3.9RV8 dinosaur in my current Stag, carefully selected because it aint anything like a flimsy TV8. Far better than the lesser engine.

BTY, the dinosaur engine was in production 30 years after the TV8 and was used by many marques. The TV8 production only lasted for the reign of 1 car, helped create a real bad image for the car & no one else wanted it. Loyalty is one thing, reality is another.

[stagmuffin]

[QUOTE=jakesmig;289118]The Stag I bought in 1978 had a TV8 engine in it, what memories, all bad. I've got a 3.9RV8 dinosaur in my current Stag, carefully selected because it aint anything like a flimsy TV8. Far better than the lesser engine.

BTY, the dinosaur engine was in production 30 years after the TV8 and was used by many marques. The TV8 production only lasted for the reign of 1 car, helped create a real bad image for the car & no one else wanted it. Loyalty is one thing, reality is

but it is a dinosaur withits own problems of overheating and cam munching but that is not what I was suggesting . The tv8 had its own problems pretty much ironed out now and only problematic if they are not understood or built well but then thats any engine right .I dont favour the tv8 either but its whats in mine built well and goes well so no need to chznge unless I want more power and bullet proof reliability the lexus v8 demonstrates this In bucket loads as do other engines out there so what I was suggesting was to open up to newer more modern designs , my loyalty lies with power and reliability old pushrod engines just dont cut it anymore thats the reality but thats my view and not intended to inflame so good luck with your old rover I hope it gives you great pleasure.

[Ian F]

I'd love to see a Stag fitted with a JLR 4 or 5 litre V8! Way, way beyond my capabilities, but how the L do you get around all the ECU issues, sensors etc. with an old Stag wiring loom. Never mind would it fit?
Imagine an XKR or XFR engined Stag - awesome......

ian F

[Westfaling]

Never mind all those little girlie V8s if I was doing a transplant... and if my engine gives me any more grief I might well be!... I'd be going for one of these.

http://www.trademe.co.nz/motors/car-parts-accessories/toyota/engines/auction-778627115.htm

Nick

[1959terry]

Has anyone fitted a BMW V8?

[Marco Polo]

Has anyone fitted a BMW V8?

I think there's a guy in the states that has done it, or it may have been a V12.

If this engine wasn't free I'd always fancied going the Jag V12 route. Just to complicate my life a little more!
regards,
Raoul

[jakesmig]

All fair points Stagmuffin Have to agree with you that a modern Lexus or equivalent would be brilliant but the plumbing and ancilliaries would put me off I think. At least with the RV8 there is plenty of working room available, the Lexus engined Stag displayed in the Forum earlier looked brilliant but awfully tight. Cooling these must be an art in itself as well.

Ian F, my RV8 uses an Emerald ECU which works using the following sensors:- crankshaft, water temp, air temp, throttle position and a lambda sensor. Not cheap but straightforward and simple to make up a bespoke loom. No distributor or coil either, mine uses 2 coilpacks. Easily tuned on a rolling road and gives great results.

Terry, we looked at installing a BMW 2.5L straight 6 into my brother in laws Scimitar but the engine had an offset casting at the rear of the sump, presumably the pump / pickup and it wouldn't have cleared the chasis. Might be the same with the V8 engines.

John.

[Escape]

We're very happy with the TV8 in our Stag, and I wouldn't change it without a very good reason (like a piston going through the block...). But I also love the RV8 (and know their weaknesses), so would like to add my views.
The Land Rover 3.9 V8 is a very nice engine, basically the same as the 4.0 my previous Range Rover (same block but cross bolted, with different heads and engine management). It's not as high revving but still lively and more torquey low down, so you'll shift earlier. No need to change the cam, the standard versions are successfully used in light sports and kitcars.
The '92 LT77 gearbox is not as good as the later R380, but not bad either. The ratio's will depend on the exact build date, '92 was a transition year. Early ones have higher ratios, with 1st being about 20% shorter than the Stag box and 5th same as Stag with O/D. Not an ideal combination with a lower revving engine. Later ones are only 10% shorter in 1st, with 2nd to 4th being almost identical and 5th taller than Stag O/D. With the early LT77 it might be best to change the diff ratio to suit.
You will off course have to remove the transfer box but if can sell it to compensate for the adapter needed to attach the propshaft. You'll also need the engine management (Lucas 14CUx) or fit Megasquirt or similar. With carbs instead of EFI it would not be a worthwhile swap in my opinion.

And as for a truly different V8, I'd love a Lotus 918 in our Stag.

Filip