Which engine to use in Series 3 build

[Silver Toad]

Hi all,

I would appreciate some advice about the best options for rebuilding a 1972 Series 3 I own. I purchased it a about five years ago but it has been sat idle for the last three years. When I bought it the engine had already been replaced with a 2.8T fourtrak engine mated up to the original transmission(albeit shifted back slightly). The engine runs quite well but the gearbox is vague and jumps out of gear sometimes. I also own an MOT failed Discovery with a 300Tdi engine which ran well but failed its MOT due to copious rust. It was bought with the knowledge that when the inevitable end came for it I would use it for spare parts for the Series.

The series is already on Discovery axles but with parabolics.  I would be grateful for any advice about whether I should keep the Fourtrak engine which means putting up with the rudimentary series gearbox or swap it for the complete engine and transmission from the Discovery which would make the vehicle much more user friendly and mean my wife could use it when necessary. 

I am unsure about what electrics would be required to fit the Discovery engine whilst keeping them as simple as possible. It is a 1994 manual transmission without egr. The electrics have played up in the discovery so I would like to not use anything superfluous to what is strictly needed. Many thanks. 

[Chicken Drumstick]

Depends what you are after at the end of the day. 
 

The Tdi engines are good engines with a nice power delivery. But they are noisy and unrefined. I’ve had one in a Series previously and it went well. But I’d not do it again. Far more harsh and unrefined compared to a Defender with the same engine. 
 

Also personally I want a Series to remain a bit Series if you catch my drift. I’d always want to retain the LT-76 four speed gearbox. It is a nice box and arguably has a nicer snappier feel to the gear change than any of the 5 speeds in later models. It also dramatically adds to the character. 
 

if you are not doing mega mileage the Rover V8 is the only sensible answer IMO 😁 smooth and refined. Known swap and still pretty to get hold of. Wonderful soundtrack too. 
 

if I’d kept my Series my plan was actually to fit a 2.0 litre T Series engine. More power than a Tdi. More low end torque than a standard 2.25 petrol. And also smooth, quiet and refined. Sadly not the easiest engine to find these days, despite being fitted to loads of Rover cars over the years. 

[Bowie69]

I'll echo much of that, Series like petrols much more than any rattly TDI, and are much kinder to the box, even in V8 form.

My preferences would likely be a 2.5 petrol, if you can find one at reasonable money (bolts up to your 4-speed), or a 3.9+ V8 with either the proper R380 or maybe with conversion kit to fit to the 4-speed. Don't both with a 3.5 unless you just want to be limited in speed 😛 The 3.9+ engines are so much more punchy.

The T-series was a lovely engine, as CD says, hard to find now.

If you do go with the TDI, then it only needs one wire to run, plus the normal wiring for starter and alternator.

Only final option for you, is maybe you can fit the Fourtrak engine to the LT77 out of the Disco, using the same conversion kit? Wouldn't be my choice, it is yours  

You don't mention SWB/LWB or 4cyl or 6cyl originally BTW, which does affect what you can fit easily.

 

 

[Silver Toad]

Thanks for the responses. I don't have loads of money to put into the build hence why I wanted to either stick with the 2.8T that's currently in the Series 3 or swap it for the 300 Tdi thats sat outside in the rusting Discovery. The Series 3 is nice but the Discovery is so much more relaxing to drive. If the electrics are as simple as only needing one wire without any of the rest of the wiring from the discovery then that is a big plus for putting that engine in, that was one of my main concerns. By the way, the Series is an 88. I don't mind moving the front of the Series forward between the wings but I do want to keep the look of having the radiator grille set back a bit. If however the chassis would need a lot of cutting and moving cross members then I would keep the 2.8T. The Series is on its original number plate and I am aware of the fact that too much modification will lose that status. By my calculations it's just over the points required at the moment and if I do change the engine with the transmission I may need to lose its current power steering and go back to the original unassisted steering to keep enough points to not have to be on a Q plate.

I just want an easy practical vehicle that's suited for the rutted narrow lanes where I live and can do a bit of towing without jumping out of gear any moment. 

[Bowie69]

Rebuild the LT76 then

 

[smallfry]

The Daihatsu is a great engine. Much better than a TDi IMO. Its just very heavy.

The Disco is a completely different thing to a Series. It has a lot of soundproofing, and transplanting the engine into a Series will NOT make it more "relaxing". A Series will still be bouncy, and needs constant steering correction compared to modern vehicles. You have to drive it, not just be a passenger.

A petrol will be more relaxing (quiet) and a V8, even a 3.5, will be MUCH more fun to drive, and driver normally will return about 20mpg. That would be my choice, even though I am not a great fan of the Rover V8 myself

 

[Silver Toad]

Thanks for the responses. If I kept the 2.8T engine and stripped down the gearbox would it be possible to get the selection of gears more positive as at the moment the gear lever is like a spoon in a pudding bowl. It's often very difficult to get the gear you want. I'm assuming that this is just how these gear boxes are because it was rebuilt not long before I bought the vehicle. I'm used to it but I would not feel confidant in letting my wife drive it which she would probably only do in the winter.

Many thanks. 

[steve b]

Probably the gearstick ball end  worn making for slack in the selector cups . when all is as it should be they are pretty positive between each gear . It's definitely not a case of "how these gearboxes are " 

Steve

[Silver Toad]

Thanks everyone. I've just put a battery into the Series 3 and the old Fourtrak engine started immediately despite sitting idle for quite a while. I've decided I'll do up the rest of the body, have a look in the gearbox and keep it as it is. I'll pinch various bits off the Discovery for the brakes, wipers and heater and probably turn the back of the Discovery into a trailer. Anyone want to buy a Discovery engine and transmission?

Many thanks.

[smallfry]

^^^^ What he said. 

When it was "rebuilt" I doubt very much anything was done with the selector

[Chicken Drumstick]

3 hours ago, Silver Toad said:

Thanks for the responses. If I kept the 2.8T engine and stripped down the gearbox would it be possible to get the selection of gears more positive as at the moment the gear lever is like a spoon in a pudding bowl. It's often very difficult to get the gear you want. I'm assuming that this is just how these gear boxes are because it was rebuilt not long before I bought the vehicle. I'm used to it but I would not feel confidant in letting my wife drive it which she would probably only do in the winter.

Many thanks. 

Like others are saying. This shouldn’t be the case. The gearbox should be lovely and positive and have a real positive “snick” as you select the gears. Sure the stick is long as is the throw. And you can’t bang it through gears at speed as though it is a quick shifter. But they should be very enjoyable boxes to stir. So I’d certainly say it is worth exploring the issue first. 

[Nonimouse]

What do you want to use the vehicle for?

[Silver Toad]

1 hour ago, Nonimouse said:

What do you want to use the vehicle for?

It's basically just a cheap second car runabout for occasional use, probably no more than 1000 miles per year. Tax exempt and dirt cheap insurance. Where we live live is pretty rural, lots of little lanes that sometimes turn into rough rutted tracks which a 4x4 is necessary for, not so much for the traction but you'd bottom out a car and get stuck(other car is a mondeo which is very low). Also a bit of towing and winter use if the snow is heavy, the roads don't get gritted much here. I think I'll do as suggested and have a look in the gearbox. It needs a new floor welded in the tub, I'm going to go through the electrics and repaint the body. Upgrade the bakes, it has disco axles so disk brakes but they don't work as well as they could yet. Contemplating either moving the bulkhead back for more leg room of making extra thin seat backs. Once sorted it'll be a great little vehicle, luckily it was wax oiled regularly by the previous owner and has very little rust and a good body, just looks very tatty at the moment. 

[Nonimouse]

On 7/23/2021 at 11:36 AM, Silver Toad said:

It's basically just a cheap second car runabout for occasional use, probably no more than 1000 miles per year. Tax exempt and dirt cheap insurance. Where we live live is pretty rural, lots of little lanes that sometimes turn into rough rutted tracks which a 4x4 is necessary for, not so much for the traction but you'd bottom out a car and get stuck(other car is a mondeo which is very low). Also a bit of towing and winter use if the snow is heavy, the roads don't get gritted much here. I think I'll do as suggested and have a look in the gearbox. It needs a new floor welded in the tub, I'm going to go through the electrics and repaint the body. Upgrade the bakes, it has disco axles so disk brakes but they don't work as well as they could yet. Contemplating either moving the bulkhead back for more leg room of making extra thin seat backs. Once sorted it'll be a great little vehicle, luckily it was wax oiled regularly by the previous owner and has very little rust and a good body, just looks very tatty at the moment. 

Keep the Diahatsu lump. Intercool it if it isn't. Rebuild the LT76. Run it as a running resto. It won't lose money and the lump is already in. If the lum,p fails, I would suggest a 2.25 petrol as a replacment...

[jaymarsden]

On 7/22/2021 at 9:19 PM, Chicken Drumstick said:

Depends what you are after at the end of the day. 
 

The Tdi engines are good engines with a nice power delivery. But they are noisy and unrefined. I’ve had one in a Series previously and it went well. But I’d not do it again. Far more harsh and unrefined compared to a Defender with the same engine. 
 

Also personally I want a Series to remain a bit Series if you catch my drift. I’d always want to retain the LT-76 four speed gearbox. It is a nice box and arguably has a nicer snappier feel to the gear change than any of the 5 speeds in later models. It also dramatically adds to the character. 
 

if you are not doing mega mileage the Rover V8 is the only sensible answer IMO 😁 smooth and refined. Known swap and still pretty to get hold of. Wonderful soundtrack too. 
 

if I’d kept my Series my plan was actually to fit a 2.0 litre T Series engine. More power than a Tdi. More low end torque than a standard 2.25 petrol. And also smooth, quiet and refined. Sadly not the easiest engine to find these days, despite being fitted to loads of Rover cars over the years. 

Yes I agree. He seems to take the words out of my mouth. Good luck with your rebuilding. I hope it turns out well.

[Romahomepete]

I have a S3 gearbox in my S2, it has done mega miles but still works OK, the gear lever is very positive, the only downside is the long throw between 1/2 and 3/4 but I can live with that.

Peter