ACR Powerplus Land rover Series 2.25 2.5 Petrol 17H swap / conversion.

[fuckwit]

For Eric Frenken & Anke Verheyen .... and Ivo van der Linden 123

1) Land rover Series 17H ACR Powerplus Petrol 2.25/ 2.5 /2.8 Petrol swap / conversion.

Be aware, this is a tidied rewrite of a post I did with another forum.

This conversion isn't strictly an engine-swap, however it kinda’ comes under that heading. Broadly the same engine as the 'common or garden' 2.25, this conversion is as easy as it gets. More correctly an engine-replacement, the 2.5 Petrol really does, 'just drop in'. No welding/ cutting/ moving battery-trays etc etc. Everything lines up, everything bolts in.

You'll use the 2.25 engine-mounts, radiator top-hose fitting; in some instances swap to a Series starter; find a 12V feed for some variants of the 17H carb, and use the 17H petrol NRC9772 Swirl Pot.
Be sure to put in a fuel-filter if running the 17H native Weber, they've a reputation for fussiness for dirt. Optional: A Stage One V8 throttle cable (with Clevis-pin) NRC5494 (fits SU very well) & Defender pedal. Bring the exhaust downpipe forward. And that's about it.

Disregarded in favour of the usual suspects, a 2.5 17H shouldn't be. The 17H 2.5 Petrol offers the character of the 2.25, yet it's sweeter, smoother, more grunty and slightly more economical. Whisper quiet too. Add the icing on the cake, ACR's kit, and a Series leafer struggles to be better.



Despite being sold for what must be 20 odd years, ACR's kit is never the herd-choice. For those of you that don’t know, ACR make a gas-flowed head/cam/SU carb / extractor 'kit of parts' for 2.25/2.5 petrol engines. Branded Powerplus. Most add this kit to the 2.25 3MB because that'll be what they have. Any of the 4-pot 2.25 LR petrol engines will do. In my mind the ideal start-point is a 17H 5MB 2.5 petrol. I say this because you'll see 200Tdi/ Lower level V8 like grunt.

I've a 17H 2.5 and I run this with ACR’s over-size pistons. This takes the 2.5 5MB out to 2.8. There's another route to 2.5: this involves crank-swaps from the 200Tdi. Take a 2.25 5MB out to 2.5 (or even 2.8).
I notice ACR offer similar over-size pistons, these added to a 3MB 2.25 to bring 2.5 - favouring 5MB, no experience of these myself.
I certainly wasn't the first to do this conversion. Nonetheless a 2.5 Petrol is rare, and it shouldn't be. Even without adding the oomph from ACR parts, this swap is a beautiful thing. What baffles me is the number of rebuilds you'd see of the 2.25 in preference to the 2.5? The 2.5 is essentially the same engine. It's why ACR's kit fits either 2.5/2.25 5MB 17H/11H / 13H or any 2.25 3MB.

More on that in a mo'...

I can't stress enough, the 2.5 gives a smoother experience with gains not shown in the figures. I shall do my best to explain why you'll grow to love this solution.



https://www.automotivecomp.com


Engine-swaps
Anyone that’s done engine-swaps , and done them properly, knows swaps are not quick, or 'real-world cheap. Even if they appear so.

Nothing lines up, thus when doing a 'swap-proper' it's too tempting to lash them in. Mostly... they are. Yet, lash it in and we'll be doing it again. The bigger cost of all these swaps is the ancillaries. Custom exhausts etc. Never forget swaps will involve knocking-about. The damage done to anything decent is best avoided. Unless we intend to cock it in, a decent exhaust adds time and hassle, factor £700-900 to all the main swaps...

Except this one.

Most think it's the cost of finding an engine. If the engine is not the easy, quick and cheap bit, your swap is set to be yet another worthless bodge. See these on eBay now.

I’ve done all the favourites. Engine recommendations are like those TripAdvisor restaurant reviews, more about the reviewer than the restaurant. Every conversion comes as a compromise, and for me anyway, the 2.5 17H approach works best.

So why a 2.5/2.8?
I write this biased to use as a 'daily-driver'. My V8 swap was nice but more knocking-about than I wanted to repeat. The V8 was 'juicy', the heat irked, and the sound although lovely, is too loud and isn’t 'very leafer'. On paper, a V8 appears the go-to solution, the reality doesn't really work.

I had a 200Tdi about 7 years back. Apologies to its fans but the swap, for my use anyway makes no sense. Yes it went well, only no amount of engine-mounts or sound-proofing, meant I had to be deaf, or prefer to limit driving-time. A Tdi powered daily-driver, for my use is unpleasant. That is not to say a Tdi is wrong. If you want cheap grunt, it’s your weekend toy, and don’t intend to drive far; or have no need for a radio, it might be the way to go. I found the 200Tdi promises instant gratification yet self-defeats - I used to wear ear-muffs, the noise ruins the experience. Most of the pleasure and character that is 'leafer-ownership' is removed. Those that base engine-choice on economy when they're not going to drive the thing, must be wiser than me; the 200TDi kills the desire to drive. The 200TDi has many fans, for which, I’m sure it’s right.

However, this took me back to my favourite, I did my numbers and a 5MB Powerplus 2.8 worked out quicker and easier. Initially it's far, far more expensive, yet long-game, cheaper and more pleasant. With the exception of a 2.6L Sixer, I’ve ‘long-term’ driven, and more importantly... lived with them all. On the surface the others tend to look a good idea; I've found they might impress for five minutes, yet don't really work when it's 'long-game'. Where ultimate driveability is paramount, and real 'liveability', you'd be wanting a 2.5 17H - preferably ACR kitted. And that's it bottled, the V8 or Tdi loses an indefinite 'something'.

Here's how I did mine:

I started in dribs and drabs with the ACR SU kit near 15 years ago.
Just the carb kit, the head a year later. I’ve had the kit as a 2.5 for near 6 years. 2.8 recently. My biggest mistake was not to fit the whole shebang in one hit. Only it's pricey; and I didn't see why I should? In hindsight, if I had, I'd never have gone to Tdi.
For me, a 17H with ACR kit is the perfect conversion. Silent as an angel's fart, but torque-laden, its real benefit is how lazy the driving experience becomes. I’ve now gone all the way to 2.8, it pulls hills in top and is ‘on pace’ with a lower-level V8. It’s slightly faster than a Tdi but appears slower because there’s no stirring the box. With a Tdi you won't want to sit in a 200Tdi for long. You move slower to limit noise. This means a 17H is real-world vastly quicker via its quietness, and the wider, lazier power delivery. Low-speed or off-road, the wider delivery knocks spots off my Tdi.

Family owned from new this 109 I do roughly 9000 a year, and it’s a real winner. Much as I ever did, I potter about at a max of 55-60mph. 55mph is about the comfortable speed for a Series regardless of how much grunt you have. A V8 or Tdi suits many, and I realise this solution sits on the fringe of the fringe. I doubt it’d suit the majority. Like as not, that's another reason it finds favour with me - precisely because it's never been the herd-choice. It's how the quiet grunt gets delivered. It’s also the whole experience which for me is pretty much the whole point of ownership. My mother or father, and my grandfather would use our leafer, listening to Radio 4 whilst we'd chat on the school-run. I do this now, with my own son.

Sentimentality is in the mix, yet cold-reasoning figures too. I run gas, and Homefill means a Tdi comes dearer to fuel. Which takes me back to sentimentality, a Tdi or V8, neither fits my mind’s eye of how our family-leafer should feel anyway. The standard swaps are somehow alien, and the overall effect leaves you to think: “Yes, but why?” I accept that’s very personal to me.

Near 20 years back, ACR were first to market. Understandably, Turner’s derided it. To a conservative customer-base, not truly understanding what ACR were doing, this was always going to be easy. These days, Turner’s - I suspect through gritted-teeth - make a muffled salute to the idea, they produce their own.

Most of you like a diesel. Quiet is my thing, this petrol is super-smooth, properly quiet and grunty. It's a 'daily'. Fuelling with gas via Homefill, makes it cheap to run.

I wrote before; Roland, the chap at ACR is a brilliant engineer, and his words are always right on it. I'll never quite grasp how Turner's are given the edge. Speak to them and it's soon very apparent they are machinists - if capable ones. Years back in the forums, the two went hammer and tongs at each other. Turner's decried the ACR approach, words to the effect that working what is essentially a block designed for diesel stresses is, all wrong, risky etc etc. This didn't stand scrutiny then, and time has borne this out. With my set-up I gather I must live in fear of things falling to bits... Ahem, where we move the goalposts slightly, the 5MB crank sits in a 200Tdi for chrissakes. It's the same part - more on that later.

One thing is true - Messrs Turner better understands the hide-bound mindset of the 'beard-brigade' customer-base. The customer-base thinks the ACR kit attempts to make a Series Land rover into a hot-hatch. These engines will never be road-burners, yet Roland’s full kit turns the page. These days, save the hard bit, that glorious cam, Turner's grant a big fat endorsement to Roland's approach, with their own version. Says it all really.

My mistake with this kit was to work in dribs and drabs, the kit really comes on song when you’ve removed each bottle-neck to air, and there's several. If you don’t, improvements are there, but with the other restrictions in place, you’ll not see 'bang-for-buck'. You're left wishing you’d gone the extra mile. For example, boy-racer 'more petrol innit' science says do a carb-swap. Unless your current example is worn, this alone can't work, and won't give bang-for-buck. The bottle-necks to an air-increase - and thus power - sit in your cam and head. Swapping a carb and thus metering the self-same air can't work. All you'll ever see is the power you were supposed to have.

How to cheat yourself?:
Run the cam and big pistons too. Don’t half-bake it, because failing to go the next notch won’t make you happy. You’ll feel you've cheated yourself. For ages I had everything fitted, but the cam. Yet, cam fitted, the other stuff comes alive. Most misunderstand what Roland is saying, and what this does. His development of this engine allows the head-work to breath right across the rev-range. The change is pure genius. Unlike a Tdi, which has you box-stirring for the impression of speed, the cam gives a wide spread of power. It’s the trick everybody misses, it becomes very driveable. Pull a hill-start from 500rpm. Sail up pretty much any hill in top, without ear-defenders. The cam/head does move peak power up by 200-300 rpm, yet most dullard the obvious. In putting out more power, there's more at the bottom. At low rpm you’ll leave a 2.25 petrol for dust. Where there is an rpm increase, it'll be because you're going faster. Thus you don't have to rev. I don't drive that way, and most of us don't. The reality has you going up hills in a higher gear, rpm is lower or identical. Unless you insist.

Be minded to why the late 2.5 5MB has extra grunt - it’s in its breathing and cam.
Land rover's final development of this engine, even in stock form the 2.5 5MB engine and its long-stroke format makes a real difference not seen in the figures. Don't under-estimate the extra torque and its usefulness. The extra power is not all about extra capacity. If it was, we'd see higher fuel-consumption. If anything, the 2.5 uses slightly less fuel. The 17H breathes better. Put a stock 200Tdi/2.5 cam [same part shared] in a 2.25, and this alone makes a difference. The head/carb and exhaust is better too.

[fuckwit]

Ignition
I use electronic-ignition. With 2.8 pistons, and Roland’s head & hi-lift cam. Most of you will get away with stock, yet there's better. I chose the 123Ignition electronic distributor, this because I run BiFuel. For me this is unusual... I'll actually go out of my way to collect useless 'tat' precisely because it lacks useful purpose. Here, I find myself, almost disappointed - 123Ignition is brilliant, it actually works. Mind, I'm rather forced, the distributor for my set-up does not exist.

123ignition's USB variant grants two programmable and switchable curves. And for set-up, on your favourite hill, you'll run two slightly differing curves, and flit in a split-second from one curve, back to the other. Even for those of you with no application for the second curve, the two curves gets you an effective rolling-road to check the mildest of tweak to truly zero-in on the right setting. 123Ignition grants a stop-watch function down to 0.1 of a second. This allows you to time a given rev-range flat-out - until you zero in. OK, a laptop in a 60YO vehicle is a tad incongruous, yet 123Ignition gives full control and does what no clock-work dizzy ever could. I have 123/TUNE-4-R-V-G. I've now verified this with a proper rolling road, I near enough cock-on.

Innovate Lambda O2 Gauge.jpg (31.67 KiB) Viewed 119325 times

Pic above:
Generally I like to find work-rounds for this sort of thing, by this I mean tat in a period vehicle? Yet I have to 'fess up, mine has to work as a 'daily'. A USB charge-port for phone and SatNav and a nod to Roland's advice, finds one of these, and he's not wrong. It's an Innovate AFR/O2/ Lambda Gauge, it helps a lot with set-up.


The purist rebuilding his dynamo:
The purist with his clockwork-dizzy, driving show-ground miles, isn’t going to be sold any 17H. Fitted with a pile of clockwork, and a flurry of facial-hair, the thing drops 5-10% because, ahem...

"it's er... easier to fix in the field".

It could be better to list those this conversion won't suit. This solution's clear-cut competitor is a Tdi conversion. Top of my local hill, the ACR 2.8 is definitely its match, with less fuss. It doesn’t become unpleasant. It’s the way it does this I like. In my mind this makes it superior. Of course, this is very subjective.

Is Deseasel set for a kicking?
If it is, those ‘Bash-it-in-this-weekend’, Tdi conversions are coming out. If a 2.5 17H set-up is for you, still sat at ’weigh-in’ prices, the last surviving 2.25 petrols won’t stay cheap. Sorry, the ship sailed if you’re after a cheap 17H 5MB 2.5. Sadly now rare, most were lost in the Tdi box-of-frogs period 10-12 years back. Those left are found in early 90/110, and valuable in their own right. Pricey today, the time for a 2.5 would be now. Once the majority of voters have sent their diesels to the breakers, the-powers-that-be seem set to quietly make diesel ownership much harder. A Tdi leafer will be the right vehicle with a wrong engine - the job needs doing twice. Even 2.25 lump prices are way up. The knives appear to be out. Along with the big knock already seen on the sale price of diesels; factor in the removal of your diesel - or the hit for leaving it in there - and dare I say, it won't be long before today's bonkers price for a 17H looks cheap?
Thus it's probably true, what you don't pay for a Tdi or a V8 conversion proper zhorst, you will pay sourcing a 17H instead.

A possible route if you're minded to rebuild anyway.
If you can't source a 17H 2.5 Petrol, the late 5MB 11H / 13H 2.25 block is an easier find. This route to your 17H comes cheapish, certainly cheaper than it sounds. Same part; that long-throw crankshaft ERR1181 is strong enough to be found in both the 2.5NA and the 200Tdi. Head issues in 200TDi (and 2.5NA unpopularity), mean these cranks are plentiful. You'll be wanting 17H 2.5 rods ERR595 and pistons. Where you can, look for the very last 2.25 found in early coilers. It'll include the superior Weber carb, exhaust manifold etc.

The following are all 5MB engines, certainly the 10H, 11H. 13H will take the 17H/200Tdi crank, not sure on the 361/364 lumps:

361xxxxxx Series III petrol 2286cc 8:1 CR 5-bearing (36123672B onwards metric)
364xxxxxx Series III petrol 2286cc 7:1 CR 5-bearing (36407286B onwards metric)
365xxxxxx Series III petrol 2286cc 5-bearing military specification
991xxxxxx Series III petrol 2286cc 8:1 CR 5-bearing (Santana)
992xxxxxx Series III petrol 2286cc 7:1 CR 5-bearing (Santana)
10Hxxxxxx 90/110 petrol 2286cc 8:1 CR 5-bearing
11Hxxxxxx 90/110 petrol 2286cc 8:1 CR 5-bearing (detoxed)
13Hxxxxxx 90/110 petrol 2286cc 7:1 CR 5-bearing
17Hxxxxxx 90/110 petrol 2495cc 8:1 CR 5-bearing

I've heard of others producing a 'Franken-17H' via a ersatz blend of a parts from a tired 3MB petrol and 5MB diesels. Not done this myself. Block and crank will be the same for an 11J and 12J for sure, and unlike a full 17H, old diesels are common and CHEAP - usually £2-300 or less.

Thus these engines give you option to create your own 17H mongrel:

366xxxxxx Series III diesel 2286cc 5-bearing
11Jxxxxxx 90/110 diesel 2495cc MOD spec
12Jxxxxxx 90/110 diesel 2495cc
14Jxxxxxx Freight-rover NA diesel 2495cc
15Jxxxxxx Freight-rover NA diesel 2495cc
16Jxxxxxx Industrial NA diesel 2495cc
19Jxxxxxx 90/110 turbodiesel 2495cc*

*Not sure about the 19J. You'd want to check.

In the real world there’s other solutions before you’d run to a 17H, mine will do 80mph+, only I'm not sure why? I did 80mph once out of curiosity, it's extremely unpleasant - it won't happen again. Most of us don’t want faster than 55-60mph anyway. However, most of us do want to hold 50-55mph - and uphill, down dale, stay at 50mph. This conversion removes the 'moving road-block' feeling, you're all too familiar with. A leafer becomes as fast as you'll need. In attempts to make a Series LR what it'll never be, some nail in any LS block and in-line GM sixers. I reckon that's best left to the Yanks and long, long tedious straight Stateside roads. A 17H suits me. 220+ bhp in, let's face it - a tractor-chassis and steering - would see me in the nearest ditch.

Yes, prices for 17H are high, yes, the ACR kit looks dear.
Sadly, since I did mine, what with a 17H in the mix, this little lot won't be cheap. It’ll never sweep the nation, yet before you eliminate such things, look to see how you’re going to use yours. What you get is a left-field solution which sits ’in character’ because less is actually messed with. Back in the day, amongst a sea of Tdi and V8 conversions I was defensive. I’ve taken the flak from the jeering mass, so forgive me for sounding more than a little smug. This conversion does the distance because it's subtle, and makes no attempt to really mess with 'The heart of driving a leafer". It still isn't 'fast'. There's no attempt to make a leafer into a road-burner or something it isn't. Simply put, if it's 70-80mph you're wanting, let's face it, virtually every vehicle on the road does the job better. To me, this sits at the root of why the once fashionable, “Yes, but why?” knuckle-dragger conversions have finally received comeuppance. They don't really work. The proof of this is those V8s stacked-up on eBay. I suspect the Tdi will follow.

The conversion that isn't?
Sadly, 'August-fakers' excepted, can't remember when I last saw a fellow leafer on the same stretch of Her Maj's highway. Running gas, I did 9,000+ miles last year, and yes, time has borne out. A 17H, particularly where ‘breathed-on’ , has a purity.

One contention is the rather half-baked zhorst-manifold ACR sell. I've had two. For mild-steel the manifold is pricey, fits poorly and won't last. I've spent a fortune trying to get these and others to mate to my Double S S/S twin-box system. The ACR offering will rot and/or gets damaged because to get it to fit at all, the system fouls and is put under strain. ACR threaten to improve it, only to date this has not happened. I can't justify a third, thus I've promised myself a custom stainless version of the ACR offering, only a one-off will be extremely pricey. In fairness to ACR it does work - Ashley & Lukey used to make these and theirs were far worse. The Lukey version didn't fit at all. The Ashley was not much better; purely under-bonnet decoration, and more noise. Ask me how I know?

With Land-rover making so many combinations, getting a universal fit is not easy. I've had several of LR part 517469 (first pipe after the manifold), they never fit. With suppliers failing to make even the stock part, what hope?. It may be with mine a 109, and a heavy bias to the 88, I get the tail-end of a proper fit? All I can say is, I've done proper battle with exhaust systems. My now NLA 'Double S' twin-box was also a fight.
Until ACR revamp the manifold, your money is best spent with the 5MB 2.25/2.5 manifold (ERC9071 or ETC5330). With a heap of fettling ERC9071 or ETC5330 can be made to fit. The down-pipe coupling differs dependent on which variant, ERC9071 or ETC5330 you find. These late design manifolds fit a 3MB 2.25 too. Over the ACR offering, ERC9071 or ETC5330 knocks torque a little, yet doesn't strangle like the 2.25 part (598473).

Part ERC9071/ETC5330 offers improvement to any of the early 2.25 engines.

ACR SU+17H Exhaust.png (315.69 KiB) Viewed 119325 times

Pic - ACR SU kit in combination with 2.5 manifold (ERC9071):

Fitment Tips
1. Standard M10 nuts do not have much clearance on a series bell housing to get a socket in. M10 flange nuts at the AF dimension are smaller - easily available and not expensive.
2. Careful: Differing flywheel diameters - The 2.5 starter fits a 2.25 flywheel housing, however its pinion won’t engage the ring-gear. Conversely, whilst the 2.25 starter fits the 2.5 flywheel housing, a larger flywheel prevents the pinion engaging. This forces use of an 2.25 starter with your existing flywheel, or a 2.5 flywheel with a 2.5 starter. Sorry, too long ago, I can’t remember exactly how I did this. I bring your attention to this.
3. Where you can, use the pre-engage 2.5 starter. It pulls less current. Lighter, more powerful, it’s a better item. The difference is being underway on frosty mornings with a below par battery, and not.
4. I used an S3 clutch. I can’t remember which flywheel housing went in. Your mileage may vary. But as said, with both assemblies in front of you, you’ll get there.
5. 17H lack a starting-handle dog. Fit ERC4672 as found the last of Series 3 with 2.25 5MB - be warned Metric thread, rare and pricey. If you're lucky, you've the rumoured Imperial thread variant, thus cheaper Series part (503665) fits and makes this a £10 swap.
Oddly the 17H Metric crank-bolt ETC7934 takes a 1-5/8 AF socket (near 41mm). Whereas Metric Dog (ERC4672) is 42mm A/F or “as near as makes no difference" 1”W Whitworth / 1-1/8 BSF. Unless you have crank-bolt ERR 605, in which case, doubtful it's easy.
6. THE 2.5 17H has a bigger water-pump outlet than the Series. Gates 3070 Rad hose (Ford Escort) is a perfect fit.
7. The weird thread on the front (temp. sender) and rear (bulkhead end) of the head (late versions of casting HRC1303) is M16 x1. ERC8973 or ERC9453 or ERC9448


In the round, with conversions out of vogue, this is the conversion, that isn't. All will be a compromise, for a ‘daily’, there will be never be an ’ultimate’ set-up, nonetheless this isn’t far off. This one leaves you with what is 'still', a Land-rover. With no departure from its essence, the 17H maintains the feel and character of the 2.25 - yet with more grunt.

And why wouldn’t it? - that’s what it is.

[fuckwit]

With different approaches to mine, here's some links from others who see the 17H's appeal:

1) Via Land Rover Monthly Magazine Sept 2021 -
Here a 2.25 11H/13H is made into a 2.5 17H hybrid, and one of those new-fangled Holley EFI Sniper whizz-bangs thrown on. Schnice.

https://www.pressreader.com/uk/land-rov ... 1/textview


2) From lr4x4 forum

A complete rebuild and EFI conversion. Wow.

https://forums.lr4x4.com/topic/106605-2 ... /#comments


3 ) Another from lr4x4 forum
Dressing-up a 17H to look like a 2.25.

https://forums.lr4x4.com/topic/101173-d ... ike-a-225/

He details removal of the HRC1303 late 5MB head, strongly suggest, don't do that. HRC1303 - a 5MB head, best head of all, comes with your 17H. If you've got one, treasure it.

4) And a 2.8 Holley Sniper:
https://www.defendersource.com/threads/ ... st#replies

https://www.youtube.com/watch?v=Tggp1wGRTSo&t=96s


And some random pix of 17H bunged in leafers. I'd credit sources for these, only sat on my hard-drive for ever, I no longer know where these came from. Thank you, you know who you are...

2.5-17H-in-Series-02.jpg (47.73 KiB) Viewed 119332 times

[fuckwit]

With my first 17H I did't realise there's several crank-pulley variants. I run a Heystee Power-steering conversion - those of you thinking P38 conversion or as me Heystee will be pleased to know LR offered Air-con, and PAS options. I've never seen the Air-con + PAS pulley. Rare. Whereas the double pulley PAS is fairly common. I think you'll find the mount/pump on the deseasel 2/5 N/A too. Piccy the PAS variant...

[DasLandRoverMan]

Looks very similar if not the same as the 200 Tdi layout?

[fuckwit]

I would think a lot of the R&D for these engines went into the TDi. Here's a bit of uncensored tri-belt hardcore aircon-pulley action on a 2.25 11H/13H 5MB

[fuckwit]

A Youtube vid of the ACR kit, on a 3MB.

https://www.youtube.com/watch?v=RtbFR4pcTXo

Another.

https://www.defendersource.com/threads/ ... st#replies

Another....

One comment refers to the 2.5 Petrol as the 'Connoisseur-choice'... who am I to disagree?

https://www.youtube.com/watch?v=bwiZlqKjm1U

A 17H w/Holley Autolite 1100 Sniper:

https://www.gunsandrovers.com/forum/gun ... l-autolite