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Old February 6th, 2011, 04:29 PM
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How to tell a 2.25 from a 2.5 petrol

There are now many early 90's and 110's coming across the ocean to these shores. I thought I would help to provide some help with the identification of the motors in these early trucks.

There seems to be a bit of misinformation going on. Though most likely unintentional, I think it is worth noting. The 2.5 petrol was not introduced until 85 or 86 yet there are a number of earlier vehicles that I have seen on offer or otherwise being discussed, indicated as having this engine. Even a few Series III's. So, here is how to identify what you have or perhaps what you are about to purchase.

There is an engine number located on a diagonal surface on the block above the factory alternator and just in front of the exhaust manifold, as in the following photos.

Going to http://www.glencoyne.co.uk/engno.htm for some help decoding the number, we find that an engine number beginning in 11H denotes a 5 bearing 2.25 petrol (detox). This detox version seems to be common for early UK vehicles.

2.5 petrol will begin with 12J for most UK vehicles.

Knowing your engine number and displacement will help when you are purchasing parts for maintenance or rebuilding. It is also my understanding that the 2.25s are NOT set up for running unleaded fuel and the 2.5s are. So, it is good to know what you have.

FWIW, the 5 bearing 2.25 engine as set up in the 90's and 110s does seem to pull a little better than the 3 bearing unit used in most Series Land Rovers, and is perhaps a bit smoother thanks to the extra two main bearings. I haven't driven the 2.5 so I can't comment on that.
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  #2  
Old February 6th, 2011, 05:35 PM
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I think that 2bbl Webber that the later 5 bearing 2.25's ran helped a little with "pull". The other differences I have noticed is that the 2.25's had a mechanical fuel pump and the 2.5 110 had an electric fuel pump, very similar (the same) as Range Rovers of similar vintage. I have no idea if this is good info or not and am way too lazy, tired, (I'm leaving out the fat and drunk as n/a) to actually research this so observations will have to do.

Seem to be seeing more and more of these in the shop, most being 2.25's with the 2.5's just starting to appear.
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new expansion complete. Not only are we the only Rover shop in Eliot Maine...now we're also the biggest.

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Old February 6th, 2011, 06:28 PM
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hmm. my 2.25 had the 'lectric pump

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Originally Posted by junkyddog11 View Post
I think that 2bbl Webber that the later 5 bearing 2.25's ran helped a little with "pull". The other differences I have noticed is that the 2.25's had a mechanical fuel pump and the 2.5 110 had an electric fuel pump, very similar (the same) as Range Rovers of similar vintage. I have no idea if this is good info or not and am way too lazy, tired, (I'm leaving out the fat and drunk as n/a) to actually research this so observations will have to do.

Seem to be seeing more and more of these in the shop, most being 2.25's with the 2.5's just starting to appear.
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Old February 6th, 2011, 09:36 PM
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Funny 'int it. I have 2 110's in right now that both have mechanical pumps. One is identical to Series bits with the glass bowl and all. The other has a pump with no glass bowl. They are both getting replaced with Series bits.
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new expansion complete. Not only are we the only Rover shop in Eliot Maine...now we're also the biggest.

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Old February 7th, 2011, 08:09 AM
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So on the topic of unleaded, am I supposed to be using an additive with a SIIA 2.25?
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Old February 7th, 2011, 12:38 PM
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So on the topic of unleaded, am I supposed to be using an additive with a SIIA 2.25?
Yes. CD2 is what I use.
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Old February 7th, 2011, 12:44 PM
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Thanks. I'll have to give that a try.
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Old February 7th, 2011, 12:48 PM
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The jury is out on that. I think valve burning and recession tends to occur at high rpms during extended highway trips. I found the additive to be a real PITA to use. I have a few bottles left over if you want to try it. Some folks say that the additives just cause deposits and buildup in the combustion chamber. This is perhaps borne out by the bottle of additive that was in my truck when I got it, and the fuzzy green and broken spark plugs that came out of the engine.

Others theorize that the lead deposited in the engines in years past is enough to provide the lubrication the valves need, and that disturbing it by lapping the valves will allow damage to begin setting in. I find this a bit far-fetched given how long it has been since leaded fuel was readily available in the USA. Not so sure what is available in the UK so not sure how that applies to recent imports.

As easy as these engines are to work on, I would just drive any Series LR without concern over the valves other than just making sure of the valve clearances. The problem is that as the valves get recessed, the clearances get closed up. This prevents the valves from shedding their heat into the head via the valve seat, which means they run hotter and get even more recessed until they just flat out burn, with potentially pear-shaped results.

Save up your pennies for an eventual valve job using hardened valves and seats. I think I spent about $450-500 to get that done back in 1996. Don't think the cost has changed that much. I let the machine shop use their seats, much cheaper @ $2.50 a pop than the $25 each RN wanted to charge at the time.


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So on the topic of unleaded, am I supposed to be using an additive with a SIIA 2.25?
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Old February 7th, 2011, 12:52 PM
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mmh. Well, I still owe her a general once over - timing check, valves adjusted, carb rebuilt or settings fixed. But these will need to get in line.

I guess I'll keep running it on unleaded, but if you can remember to bring a bottle to HH, one tankfull can't hurt
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Old February 7th, 2011, 12:56 PM
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Ron, sitting in the garage I think you'd better add some STA-BIL and some HEET.




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Yes. CD2 is what I use.
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Old February 7th, 2011, 01:07 PM
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Ron, sitting in the garage I think you'd better add some STA-BIL and some HEET.

used is more like it true

I drained all the gas a couple years ago so no need for sta-bil
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Old February 7th, 2011, 03:16 PM
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In looking for a replacment engine for my 2.25 I have been told that the 2.5 is basically a stroked 2.25. I does run a different distributor as well. Parts for the 2.25 are readily available but I was told that 2.5 parts are scarce. A rebuilt "stripped" 2.25 petrol engine was quoted to be 2800 UK pounds shipped sea freight to Norfolk VA. Even with a recon carb and new points and timed in various ways as suggested by the UK forums the 110 was a pig to start compared to my other 4 Rovers, Again from the UK forums this is not unsual
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Old February 7th, 2011, 04:02 PM
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suggest we start a new thread here but that is a shiteload of money. why not rebuild what you have or just toss in a tdi?

I have trouble believing that the 2.5 parts are so rare. They were in use for longer than the 5 bearing 2.25.

Though if you are comparing 3 bearing 2.25 vs. 2.5 then yes there are tons more parts for the 3 bearing. Especially in the USA. Though quality may be an issue with the more commonly available aftermarket stuff. That engine was in use in one form or another from 1958 through the early 80s.

The 5 bearing 2.25 went from 83 or 84 to 85, the 2.5 from 85 on to 94. So I would venture to say the real odd duck is the 5 bearing 2.25, not the 2.5 litre.

My 5 bearing 2.25 would start first turn of the key every time. I wonder if your float bowl is draining out or some other issue?


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Originally Posted by kjva View Post
In looking for a replacment engine for my 2.25 I have been told that the 2.5 is basically a stroked 2.25. I does run a different distributor as well. Parts for the 2.25 are readily available but I was told that 2.5 parts are scarce. A rebuilt "stripped" 2.25 petrol engine was quoted to be 2800 UK pounds shipped sea freight to Norfolk VA. Even with a recon carb and new points and timed in various ways as suggested by the UK forums the 110 was a pig to start compared to my other 4 Rovers, Again from the UK forums this is not unsual
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Old February 7th, 2011, 04:07 PM
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I can only pass on what I was told by Turners who build a lot of engines. That was my source of info on the 2.5 spares siutation
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Old February 7th, 2011, 04:19 PM
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Fair enough. Turners who sold a friend of mine a rebuilt engine with a head that had a step milled in the mating surface. Don't ask why we pulled the head off a functioning engine in the middle of a field, that is another story. It was enough of a step you could catch your fingernail on it.
They insisted it was ok and that all was within tolerance.

That said, 12 years later the engine is still running fine, so I guess it was.


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I can only pass on what I was told by Turners who build a lot of engines. That was my source of info on the 2.5 spares siutation
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Old February 8th, 2011, 12:49 AM
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The 4 cylinder engines can be surprisingly interchangeable. I once built a 2.5L gas by putting the timing casing and head from a 2.25L gas engine onto a 2.5L na diesel short block, diesel pistons and all. It was the best 4 cylinder gas rover engine I've ever run
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Old February 8th, 2011, 01:20 AM
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Quote:
Originally Posted by Ren Ching View Post
There are now many early 90's and 110's coming across the ocean to these shores. I thought I would help to provide some help with the identification of the motors in these early trucks.

There seems to be a bit of misinformation going on. Though most likely unintentional, I think it is worth noting. The 2.5 petrol was not introduced until 85 or 86 yet there are a number of earlier vehicles that I have seen on offer or otherwise being discussed, indicated as having this engine. Even a few Series III's. So, here is how to identify what you have or perhaps what you are about to purchase.

There is an engine number located on a diagonal surface on the block above the factory alternator and just in front of the exhaust manifold, as in the following photos.

Going to http://www.glencoyne.co.uk/engno.htm for some help decoding the number, we find that an engine number beginning in 11H denotes a 5 bearing 2.25 petrol (detox). This detox version seems to be common for early UK vehicles.

2.5 petrol will begin with 12J for most UK vehicles.

Knowing your engine number and displacement will help when you are purchasing parts for maintenance or rebuilding. It is also my understanding that the 2.25s are NOT set up for running unleaded fuel and the 2.5s are. So, it is good to know what you have.

FWIW, the 5 bearing 2.25 engine as set up in the 90's and 110s does seem to pull a little better than the 3 bearing unit used in most Series Land Rovers, and is perhaps a bit smoother thanks to the extra two main bearings. I haven't driven the 2.5 so I can't comment on that.
Nice info! My rig, it has a 2.5L Milspec 5 Main Bearing engine w/ a Turner Engineering head (oversized valves / high lift cam / headers). My rig is a bit of a hybrid so I'm not sure what all matches up. Numbers on the top of the head (V4227 / HRC 1303 / 5). As far as the block (188UE A) shows up under the intake manifold and (VWA-02) to the left of the alternator. All of the numbers are raised numbers except for the V4227 that is stamped into the head.

Wish i could give some comments on the difference between the two but I've never driven a 2.25 and my 2.5L is mated to an LT77 / LT230 setup. Fantastic on the highway though. I do use regular petrol.

















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Old February 8th, 2011, 08:32 AM
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Ditto the use of "lead" additives to gas. The exhaust valves will probably not see any damage under normal driving. If you were to run the thing WFO for hours on end, then maybe. You still have inserts, just not as high on the Rockwell scale as later engines. And we're talking about a low rpm loafer of an engine here anyway, not some race motor.

I wonder whether it would be of any use to put EFI on one of these 2.5 engines to see if they'd do better with gas.
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Old February 8th, 2011, 11:00 AM
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I have yet to own a LR with a 2.25 that I haven't driven WFO for hours on end. So that *is* normal driving for me. AFAIK they do not have inserts. The seat is ground directly into the cast iron. Valve recession and burning are not boogey-men, they can and do happen. I don't think that the additives really help and I think the best remedy is a rebuild with the correct unleaded bits.

NC Rover, does your engine not have a number stamped into the block in the area shown? Someone did EFI before. Doubt it is worth the hassle and expense. Maybe at higher altitudes.

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Originally Posted by o2batsea View Post
Ditto the use of "lead" additives to gas. The exhaust valves will probably not see any damage under normal driving. If you were to run the thing WFO for hours on end, then maybe. You still have inserts, just not as high on the Rockwell scale as later engines. And we're talking about a low rpm loafer of an engine here anyway, not some race motor.

I wonder whether it would be of any use to put EFI on one of these 2.5 engines to see if they'd do better with gas.
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  #20  
Old February 8th, 2011, 12:11 PM
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Meh, 4 bangers are for econoboxes.
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