Is it worth swapping out my worn 2.25 D for a 2.5 D

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Pezer

New Member
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7
Hi Guys
Only want answers for changing to a 2.5 na Land Rover diesel,(not a 200tdi or a v8 or any other engine or manufacturer) please.

I have to pull the engine on my series 2a which was originally petrol but I replaced the worn out petrol lump with a 2.25 diesel series 3 engine about 25 yrs ago. I have been having issues with the engine so am going to pull it out and investigate.

I want to try and stay sympathetic to the series Land Rover so don’t want to put a 200tdi in it.
I have thought about replacing it with a 2.5na diesel engine. I do have a petrol 3 bearing engine and have thought about putting it back to what it was, but i’m worried that the cost of petrol will put me off driving it.

I say this as I live on the south coast but want to do some green lanes in wales and other parts of the country with a roof tent and may be some exploring into Europe and may be Morocco and Tunisia one day (probably won’t happen but it’s a dream)

I like the fact the Land Rover is Tax and MOT exempt so this is a consideration in changing the engine to a 2.5.

My question is does the 2.5 make much difference over the 2.25 in terms of drivability,is it as reliable as a 2.25, is it easier to tune up (eg fuelling), is it a bit smoother, quieter, and torquier then the 2.25 will it give me a bit more grunt off road when tackling some steeper trails in wales and Scotland. I know it is still a noisy slow and under powered engine but is it better then the 2.25 or should I just rebuild my 2.25 and stick with that.

Cheers
 
Petrol is much cheaper than diesel right now and i don't think that's going to change. The petrol is also a bit more economical than the diesel and easier to drive, quieter too. Your fuel bill will go down a bit
 
The 2.5 is based on the later 5 main bearing 2.25 68HP unit and while not exciting in power in good order will give about 10hp more and about 15 more torque LBFT. Nice thing it is pretty much a straight swap.
A petrol 2.5 will be about 83HP 133 lbft [ about 18 more HP more than 3 bearing unit] and be quieter to drive.
Re @kermit-rr above while petrol will use more fuel its price fair bit lower than diesel at this time.
 
Just done that swap.
Running a series type timing cover with a chain drive to the cam.
Running a 2.25 type injector pump in the traditional position.
Runs great.
Visually it looks just like a five bearing 2.25 diesel.
Only problem is you need the torsional vibration damper type front pulley off the five bearing engine.
Genuine ones about £250+
The were some pattern ones around, but I think I bought the last two.
 
As you didn’t mention the 200di, here it is, I also didn’t want to go to radical and keep it a simple swap
My swap keeps battery and oil bath filter under bonnet uses same engine mountings, gearbox, exhaust without the extras of oil cooler and turbo leaving lots of access still under bonnet
IMG_0967.jpeg
 
I always liked the petrol two and a quarter for the series landies. Have you considered a 2.5 petrol engine? Not cheap now and very sought after but a very good engine.
 
My 2.5n/a is incredibly loud, like noise defenders don’t even drown out much of the noise at 45mph loud, might have to post a video soon and see if that’s normal…

Haven’t had the opportunity to drive a petrol series so can’t really compare
 
As you didn’t mention the 200di, here it is, I also didn’t want to go to radical and keep it a simple swap
My swap keeps battery and oil bath filter under bonnet uses same engine mountings, gearbox, exhaust without the extras of oil cooler and turbo leaving lots of access still under bonnet
View attachment 331665
I am now coming round to the idea of a 200tdi to sort of future proof it, especially if I want to do some long trips and have some adventures and running one with out the turbo and intercooler, and with the oil bath filter to add a bit of visual authenticity has got me very interested 😀, How does it run in terms of drivability and power with out the turbo compared to the older 2.5 na, and have you got any idea of mpg.
 
I am now coming round to the idea of a 200tdi to sort of future proof it, especially if I want to do some long trips and have some adventures and running one with out the turbo and intercooler, and with the oil bath filter to add a bit of visual authenticity has got me very interested 😀, How does it run in terms of drivability and power with out the turbo compared to the older 2.5 na, and have you got any idea of mpg.
They really are very good.
A totally shagged out 200tdi is still better than the older engines.
But and it is a big but, they are pretty noisy inside the cabin, Glencoyne engine mounts certainly help, cheapest fix is them squishy earplugs that take the harshness out of the noise.
As for economy it will be much the same as a 200tdi defender ie circa 30 mpg, IF you have the 3.5 diffs fitted.
 
My 2.5n/a is incredibly loud, like noise defenders don’t even drown out much of the noise at 45mph loud, might have to post a video soon and see if that’s normal…

Haven’t had the opportunity to drive a petrol series so can’t really compare
My 2.25 D is that loud, it’s just the nature of these diesel engines, once I am happy with my engine I will start a extensive noise insulating project, so I can talk to my passenger😂
 
My 2.25 D is that loud, it’s just the nature of these diesel engines, once I am happy with my engine I will start a extensive noise insulating project, so I can talk to my passenger😂
Does that include selling the car and getting something more modern? 🙄

Talking has been shown to be a distraction, so your landy is actually safer than a modern car 😂😂
 
They really are very good.
A totally shagged out 200tdi is still better than the older engines.
But and it is a big but, they are pretty noisy inside the cabin, Glencoyne engine mounts certainly help, cheapest fix is them squishy earplugs that take the harshness out of the noise.
As for economy it will be much the same as a 200tdi defender ie circa 30 mpg, IF you have the 3.5 diffs fitted.
What sort of speed/acceleration can you get out of it, i can get up to 50 quite easily and can cruise at 55 though a hill will dramatically kill these figures, in my 2.25 and can achieve 60 on a decent B road with out to much difficulty though 63 is max. I would be hoping to achieve 70 with a 200Di though 60 is enough in a series. It’s just people have mentioned that the engine is designed to run with a turbo so the pistons, fuel injection and flow systems are designed for this purpose, so wondered if these then cause a hindrance to the engine when turbo removed. Is there then much tuning to do with engine so it works correctly with out turbo. Also are you any where near Hampshire as would love to come and see your rover and have a chat. Thanks
 
I really need to update this with my Di,
Top speed will be limited by revs unless you change the gearing

 
The older Land rover diesels are indirect injection, fuel is injected into a precombustion chamber, flame then travels through a hole into the head/piston chamber. This results a less harsh detonation [ NOISE ] Tdi's have direct injection straight into the head space and you get more of the "diesel" rattle Not as much as old tractors due to the injection system but still.
 
What I don't think that anyone has mentioned, is that another effect of direct injection is that the torque "pulse" from each cylinder firing is much sharper than with indirect injection.
This, I believe, is why so many people have wrecked their gearboxes using Tdi engines.
If you're aware of the issue, and use the gearbox sympathetically, you'll not have any problems.
I had a neighbour who killed a series three box within a month of fitting a 200Tdi.
OK maybe the box was ready to fail anyway, but he was driving a fully loaded 12 seater station wagon, towing a large touring caravan.
Too much for a series transmission ?
 
It would have been on the limit for a series box, more so if a 2/2a box. There has for many years a belief that the late 2a box is the strongest. This is not so the series 3 box with its one piece layshaft is the strongest. That is not to say it does not have issues but in good order and treated kindly as @grewth says it will serve well, steady changes, easing clutch in with every change and not using the clutch like an on off switch as many do driving today. Change down early keeping revs up some. Tdi's develop a lot of torque low down the power band. It is what makes them the best off road diesel engine.

Before 200tdi's V8's were being fitted to series and the same things happened with transmissions, those that drove with sympathy were fine.
 
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