The easiest and best 2.5 -30 petrol swap for 1985 defender

[Ahmad_sama]

Hello brothers I have 1985 2.5 carburetor engine  and its so bad on fuel like 20L/90-100km

And where I live you can't swap from petrol to diesel... so bad that means I can't get 300tdi 

And I can't go up to 3000 cc  I can only  get from 2.4-2.7 cc

My gear box is lt77 with 20d code (I think it means slow low gear)

Sorry I'm zero in In mechanics

And I Don't want to ruin my car

 

Some say get 1jz vvti non turbo.. but my engine is 83hp and jumping to double 190hp I have bad feelings

And thank you guys  wish you help me

[steve b]

Welcome to the forum.

That is very bad fuel use , even for a 2.5 petrol 

There may be room to improve the set up as it is. Making sure spark plugs and ignition timing are correct and fitting an electronic contact breaker replacement is worth it. Check valve clearances and set the Carb to best emissions . 

It should be 12-14 l/100km roughly.

What sort of mix of surfaces/terrain are you on?

Steve 

[Nonimouse]

Marhaba

I think you have various options here:

1). The 2.5 engine is a pretty tough engine, but lacks sophistication. It reacts well to forced air induction. Especially supercharging, with a charge cooler.  I would suggest a complete re-build of the original engine; big ends, little ends....then swap to an SU side draft carb. Probably a well jetted HS6. Speak to these people https://www.automotivecomp.com/.... but don't expect more than a few MPG gain

2). Find the most common, reliable in line petrol engine available in your area. 

What is the vehicle and what do you do with it? If it's a 110 with a 1.66:1 tbox in it, just swap to a 1.44: 1 for better gearing

Alternatively if it's a 90 you could probably manage a 1.22:1 t box if the engine is good

[Ahmad_sama]

My father drive about 14km every day to the farm  and the road is straight without hills

 

[Ahmad_sama]

1 hour ago, Nonimouse said:

Marhaba

I think you have various options here:

1). The 2.5 engine is a pretty tough engine, but lacks sophistication. It reacts well to forced air induction. Especially supercharging, with a charge cooler.  I would suggest a complete re-build of the original engine; big ends, little ends....then swap to an SU side draft carb. Probably a well jetted HS6. Speak to these people https://www.automotivecomp.com/.... but don't expect more than a few MPG gain

2). Find the most common, reliable in line petrol engine available in your area. 

What is the vehicle and what do you do with it? If it's a 110 with a 1.66:1 tbox in it, just swap to a 1.44: 1 for better gearing

Alternatively if it's a 90 you could probably manage a 1.22:1 t box if the engine is good

Thank you both for replying back  yes mine is 1.667

 

And I can add supercharger for 2.5 carburetor??? Wow that's good news for me

 

Anything better than 20L/100km  would be so good

I have 1985 110 County def

I was like 2 years in  a bad mood  searching for answers to my questions

You guys made me smile

Edited December 4, 2023 by Ahmad_sama

[FridgeFreezer]

That's a nearly 40-year-old engine so it's probably due a good tune up & maybe even a rebuild - as Nonimouse says there's lots of room for improvement on those engines too as they were massively de-tuned for poor fuel etc., Turners & ACR do "performance" heads for them and the fuelling & ignition can be upgraded with electronic ignition, better carbs or even basic fuel injection.

But first thing is to give it a really good service, check & adjust everything, check/clean/set the ignition & carb up properly and see what happens.

[Ahmad_sama]

What do you think of the 2tr 2.7 or the 1jz vvti non turbo  swap ? For the Defender 

[Nonimouse]

Being honest, it's not a simple job and the strain on your drivetrain would be expensive, so once the swap is done, you would need to spend more on a stronger drive train, brakes and so on.

Gazzer, on here is converting a 2.5 to fuel injection, which is actually relatively straight forward, especially as Jordan has a good import/export with the USA....

But start simple. Big service and overhaul. Work your way through the engine until it's as good as when it left the factory (give or take). Then look at options. ACR do a whole world of nice parts for the 2.5, except their manifolds, which are nasty) and they also do jetting to suit superchargers!

Head work you could get done locally. These engines like a skim and porting. The Webber they are fitted with is the sort of carb you fit so that the engine will run on any octane fuel and 90 degrees out of time... although they do have a habit of eating their low fuel sensor. I would investigate better electronics. You've probably got points; maybe the time has come to go electronic

But first give it some love

[Anderzander]

11 hours ago, Nonimouse said:

 

But first give it some love

❤️ ☝️

[FridgeFreezer]

12 hours ago, Ahmad_sama said:

What do you think of the 2tr 2.7 or the 1jz vvti non turbo  swap ? For the Defender 

High strung car engines are not necessarily good swaps for a 2-ton brick that needs broad torque spread and high torque from idle - the 2.25 might make very little power but it's a slugger that will tick along at idle off-road.

If you know how to do engine swaps then go for it, if you have to ask it's probably not a DIY project - also even if you get the engine for free and engine swap can still end up costing a lot of time & money, and that buys you a lot of fuel.

[Ahmad_sama]

Thank you men  you changed my mind for the better way 🤝🏻👍🏻

[Ahmad_sama]

17 hours ago, Nonimouse said:

.

Gazzer, on here is converting a 2.5 to fuel injection, which is actually relatively straight forward, especially as Jordan has a good import/export with the USA....

 they also do jetting to suit superchargers!

 

But first give it some love

Thank you brother  can you tell me what 2.5 fuel injection he did use ? 

And can you tell me what is the best supercharger to add (Regardless if I convert the engine to an injection or keep it as it is with a carburetor) 

Sorry for my bad English by the way

 

 

[Daan]

A higher compression ratio will help run it more efficiently as well. Skim as much of the head as you dare.

[Nonimouse]

19 hours ago, Ahmad_sama said:

Thank you brother  can you tell me what 2.5 fuel injection he did use ? 

And can you tell me what is the best supercharger to add (Regardless if I convert the engine to an injection or keep it as it is with a carburetor) 

Sorry for my bad English by the way

 

 

Your English is excellent

If you do a search for Gazzer on here, you will find his many useful threads. I would do a link, but I'm technically not that advanced.

As for superchargers, I would look for the best you can find; but over here, we have plenty of scrap yards and breakers. BMW Mini Cooper S1.6 have lovely little superchargers and I have been involved in fitting one to a Mazda MX5. The origional Land Rover 2.25 petrol supercharger modification used a Shorrocks supercharger, but they aren't easy to get hold of, unless you have a very healthy classic car scene in Jordan

Worth noting that unless you drive accordingly,  a "turbocharger provides better fuel efficiency and reduces emission, but boosts power at a specific rpm resulting in turbo lag. A supercharger instantaneously boosts the engine’s power but results in more fuel consumption", 

[FridgeFreezer]

50 minutes ago, Nonimouse said:

BMW Mini Cooper S1.6 have lovely little superchargers

I can confirm they're hilarious.. but they're not going to save you any fuel.

In fact there's a limit to how much fuel efficiency you can ever get out of a 2-ton 4WD brick, and there's a law of diminishing returns to tuning engines or even spending money on engine swaps to try and chase a few MPG improvement.

Given that OP can't swap to diesel and can't swap to a much bigger (or presumably much smaller) engine I doubt you're going to see a massive improvement out of any of the options.

[Ahmad_sama]

Thank you all brothers 

[Blanco]

As you have little mechanical ability yourself at the moment (that might improve?) I just think that finding a trustworthy garage to help with this work is the biggest priority, .... in the short /medium term, improvements to the existing set up are bound to be the most cost effective, and I think that transfer box has to go. Engine swaps should only be contemplated if the workshop involved has a proven track record with the engine concerned, and can quote confidentlyy about the costs. 

 

[Nonimouse]

Economy, in this situation, is added to in increments. For example, a change in oil type, quality of regularity may achieve 1mpg more. Correct gapping of spark plugs may achieve 1/2 a mile extra, replacing the air filter for a clean OE one (never use K&N or similar) may give another 1mpg.

Improving an engine is about 4 things spark, timing, fuel flow and air/exhaust flow. The first two are well serviced by the aftermarket; electronic ignition is cheap and simple to replace eg: https://www.lrparts.net/etc5835-electronic-conversion-kit-for-lucas-type-distributor-on-land-rover-series-2a-3-and-defender-2-5-petrol.html. A decent quality coil  and plugs (correctly gapped). Depending on the miles on your engine, it's timing chain may have stretched - this needs to be part of the 'big service', timing is critical wit  these engines, as they will run about a day out of time, but as rough as anything

Fuel flow is governed by the lift pump, filters, tank breathers and carb. The carb is the tried and trusted Webber 32/34 https://www.scparts.co.uk/en/land-rover/land-rover-90-110-and-defender-1983-2006/carburettor-fuel-injection-and-air-filter/carburettor-32-34-dmtl-weber-2-5-litre-4-cylinder-petrol-engine/  It's relatively simple and relatively reliable. It's definitely not as efficient as a side draft carb, which is the route I would go down

air exhaust flow, is all about letting the air/fuel mix and exhaust take the easiest route, items like a stage two tune to the head, tubular manifold, slightly bigger bore exhaust etc. Read up on the internet. Dave Vizzard wrote some excellent books on tuning different types of engines.

 

 

 

[Ahmad_sama]

On 12/7/2023 at 12:47 AM, Blanco said:

As you have little mechanical ability yourself at the moment (that might improve?) I just think that finding a trustworthy garage to help with this work is the biggest priority, .... in the short /medium term, improvements to the existing set up are bound to be the most cost effective, and I think that transfer box has to go. Engine swaps should only be contemplated if the workshop involved has a proven track record with the engine concerned, and can quote confidentlyy about the costs. 

 

Thank you 

[Ahmad_sama]

On 12/7/2023 at 3:41 PM, Nonimouse said:

Economy, in this situation, is added to in increments. For example, a change in oil type, quality of regularity may achieve 1mpg more. Correct gapping of spark plugs may achieve 1/2 a mile extra, replacing the air filter for a clean OE one (never use K&N or similar) may give another 1mpg.

Improving an engine is about 4 things spark, timing, fuel flow and air/exhaust flow. The first two are well serviced by the aftermarket; electronic ignition is cheap and simple to replace eg: https://www.lrparts.net/etc5835-electronic-conversion-kit-for-lucas-type-distributor-on-land-rover-series-2a-3-and-defender-2-5-petrol.html. A decent quality coil  and plugs (correctly gapped). Depending on the miles on your engine, it's timing chain may have stretched - this needs to be part of the 'big service', timing is critical wit  these engines, as they will run about a day out of time, but as rough as anything

Fuel flow is governed by the lift pump, filters, tank breathers and carb. The carb is the tried and trusted Webber 32/34 https://www.scparts.co.uk/en/land-rover/land-rover-90-110-and-defender-1983-2006/carburettor-fuel-injection-and-air-filter/carburettor-32-34-dmtl-weber-2-5-litre-4-cylinder-petrol-engine/  It's relatively simple and relatively reliable. It's definitely not as efficient as a side draft carb, which is the route I would go down

air exhaust flow, is all about letting the air/fuel mix and exhaust take the easiest route, items like a stage two tune to the head, tubular manifold, slightly bigger bore exhaust etc. Read up on the internet. Dave Vizzard wrote some excellent books on tuning different types of engines.

 

 

 

Thank you king for your advice and time 

[Ahmad_sama]

On 12/7/2023 at 3:41 PM, Nonimouse said:

I have another question, if you'll excuse me. In some way, the Jordanian Ministry of Interior allowed me to install a large-capacity engine. Which Land Rover engine do you recommend? 3.9 4.0 4.5 4.6 

All what I care about is Reliability, lack of problems, and visits to the mechanic

And better mpg

The best of the engines I mentioned, even if all engines consume a lot of gasoline

 

Edited December 16, 2023 by Ahmad_sama

[Daan]

Can you go smaller in engine size? The Ford Ecoboost engine looks like a good option, and will definitely be more efficient:

 

[FridgeFreezer]

7 hours ago, Ahmad_sama said:

I have another question, if you'll excuse me. In some way, the Jordanian Ministry of Interior allowed me to install a large-capacity engine. Which Land Rover engine do you recommend? 3.9 4.0 4.5 4.6 

All what I care about is Reliability, lack of problems, and visits to the mechanic

And better mpg

The best of the engines I mentioned, even if all engines consume a lot of gasoline

It depends a lot on what you have locally - you will never get great MPG from a big brick with a 4x4 system and there is point fitting a "rare" engine that then causes a headache every time you need something for it.

Over here if people want MPG they fit a turbo diesel (200TDi, 300TDi, TD5, Mercedes OM606 or BMW M57).

Any of the Rover V8's with fuel injection will give MUCH better performance and can give better MPG than the old 2.5 as long as you can keep your foot off the accelerator, in a 90 the 3.9 or 4.0 might be a good call but in a 110 I'd go straight to the 4.6 as there is no substitute for torque and it will be very relaxed. With a V8 you could also put a 1.2 ratio transfer case in from a RR or Disco to drop the RPM when cruising, assuming you don't have big tyres.

I can get 18-22mpg out of my 4.6 if I cruise at the speeds you'd do with a 2.5 and drive gently, but I don't do that so it's usually 16-18mpg.

[Nonimouse]

On 12/16/2023 at 5:52 AM, Ahmad_sama said:

 

I would go by what Fridgefreezer said. 

[Carloz]

On 12/4/2023 at 4:52 PM, Ahmad_sama said:

My father drive about 14km every day to the farm  and the road is straight without hills

 

That short distances makes bad mpg too. But well in Jordan the cold start is on most days not that cold I guess?