Theoretical exercise RRC engine swap

[Mercguy]

Let's start with a few basics before I launch into a monologue....

1. Oct 1991 build RRC 3.9 v8

2. BW viscous xfer case

3. Standard differentials.

OK.

the Theoretical Challenge is to devise a list of required modifications to enable te fitment of either a diesel (turbo) inline 6 engine or a larger displacement OHC v8 from another manufacturer - in this case Mercedes-Benz.

engine #1 is well known in diesel circles as OM606. I also have access to OM603's but would prefer the DOHC.

engine #2 is high compression 5.6L M117 SOHC petrol engine. Known to be almost indestructible and makes reliable power. Can be supercharged without messing with internals.

The theory behind the swap is simply to improve low end torque and fuel economy.

The existing 3.9L v8 is a bit of a gutless wonder I find. It always needs encouragement to go up hills on the legal highway speed limit, and often drops 10-15km/h if the throttle application is not correctly timed or sufficient - or for example when you have less than favourable traffic in the left lane and you need to get past going uphill and towing a small boat.

So I have a spare v8 Mercedes engine, and it's a good'un, but my concern is simply whether the ZF and BWTC can handle the extra torque.

I can access an OM 606, but dimensionally I have concerns about the length and engine bay fitment.

I have seen the TDV6 swap in P38A, but I am not interested in common rail piezo injectors. If I run the OM606, it will be with a modified 603 pump, possibly with 7mm elements just to enable a little more boost without worry.

So after the basic bits - getting engine mounts sorted, bellhousing adaptors etc... I have to wonder if the auto and transfer case will take the punishment... and if they can, then what about the axles & CV's?

These are the things I am not sure about. So feel free to throw in some ideas or if you have information to add, please do.

Right now the swap is theoretical only. the 3.9 is working fine, albeit with a thirst and not a great deal of mumbo. I can live with that for now.

So feel free to add your suggestions.

[loanrangie]

I have been drooling over some of the om606 lr conversions on some of the uk forums, they fit in a defender so an rrc should be ok.
Auto would be ideal but i think you would have to use zf hp24 for it to last, from my little research the om606 is no easy to find in oz.


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[Mercguy]

For me sourcing a 606 is a doddle. It's pretty much the least of my concerns, however they are becoming increasingly sought after, so it makes them more and more expensive these days.
an OM603 would still be okay, but for that kind of swap I'd rather drop the v8 in.
Done the m117 into a Gwagen before so not worried, but since I'm an RR novice so to speak, I think the concerns for me are whether or not the ZF auto will last, whether the ratios are any good for a 5.6 v8, or if I should utilize the bulletproof 722.6 mercedes auto and programmable shifter.

Then I guess it would simply be easier to have bought a Gwagen instead, so perhaps just a 606 would do for the moment.

The BW transfer case is a concern because I do not know how much power it can handle or how good they actually are.

diffs / cv's I can live with until I learn some more about which are strongest and whether or not I swap out whole axle assemblies or just gut the internals.

I would like to do something about wheels & tyres down the track, so one of the key criteria for the swap will be if I can run a nice 33 or 35 MT or centipede etc and 'try' to keep it stock looking.

[loanrangie]

I would ditch the BW for an LT230 then there are no concerns, HP22 wont last long with 250 plus HP going thru it which is why i mention the HP24 even though it will need an after market controller.

If you look on LR4x4 there are a few OM conversions.

[Mercguy]

I think if I were to pursue the OM606 route, then I would be utilizing a 722.6 transmission, not the ZF. Mostly because I am extremely familiar with the 722 series MB transmissions (and they are pretty much unbreakable if fluid & filter service intervals are followed).
If I go with my spare m117 5.6, then the 722.323 that sat behind it would be utilized, - All MB transmissions can have the valve body modified (remove a couple of check balls and springs) to have manual lock out in gears and also the 1st gear start (most 722.3/4/5/6 transmissions start in 2nd gear for sedan applications)
the only major differences between the sedan transmissions and the Gwagen (w461/463) are the depth of the sump on the trans pan (identical bolt pattern, just deeper) and the manual gear lock modes.
Of course, using one of these means the transfer case must be divorced from the rear housing. I'm not entirely sure it's a good idea, but it does complicate things further, in terms of mounting etc. It does provide some alignment freedoms, but I have seen this become more of a problem than a boon in the past.
Another issue seen with the 5.6 swap, is torque loading.
In the 'G560' (was a 280GE) the amount of torque at idle loaded up the drivetrain in the G, so that holding the brakes and applying the tiniest amount of throttle, compressed the suspension by almost 4" of travel. Of course, G's have incredibly short diff ratios, and this was the primary cause. Burnouts however, in 1st, 2nd and 3rd gear were just a matter of applying a decent amount of wellie.
1st gear was deemed too short for anything but quite serious offroading, and low range outstanding. The vehicle really needed a set of 35" tyres, but it wasn't mine... so it remains to be seen how the owner contends with the short final drive issue.

I like the idea of the viscous coupling, but understand the issues it comes with, but it's nice to have fulltime 4wd. an LT would obviously change that.
I have fitted quaife ATB centres to my MB's before and would think that this would be an ideal alternative to an open centre transfer case, but again, I do not know the strength of the LR parts, or what needs to be done to achieve that 'bulletproof' reliability.

The main issue I have with contemplating the swaps, is simply turning the vehicle into a bastardized unit. I see many conversions, LS's Cummins, duratechs etc... they all have their advantages, but they also come with a number of penalties that owners either persevere with or become frustrated with.

So while I simply have a single issue with the 3.9 in that it is a gutless wonder and drinks like a sailor, I can live with it, as it is simply a fuel consumption issue.
Mind you, I never had the same feeling in my old GQ, or even the old 78 series utes I used to drive (loaded with 2 tonnes of equipment) - and yes, the tojo was the 4.2 diesel.....

So, will the 606 be worth it? possibly. certainly has the torque and power spread to make the RRC get up and really boogie, with the added reliability of the inline 6 mercedes donk. But I do wonder...... is a diesel conversion actually worth it, when outlay versus consumption over say... a 5 year period of ownership is concerned.

To give you an idea of consumption..... I'm currently hovering around the 20L/100km without trailer attached and about 26-28 with. I do mostly highway work, and find that 4th gear is a waste of time with the trailer, except on flat pavement. It's actually not much different without the trailer in that respect, and I would opine that the 3.9 wouldn't pull the skin off a rice pudding when really trying to get it moving from 90km/h upwards. That includes kickdown etc. it just revs and doesn't accelerate, especially uphill where it even loses momentum under kickdown - especially at around 90-100km/h. If this is normal for an RRC, then fine, but I would expect some form of acceleration with the kickdown from 4th to 3rd (and sometimes 2nd?) when the momentum drops like a stone.

So yes, I think a 606 or 117 would be an instant cure for that. however, in my old lwb 560SEL the fuel consumption was around 14/100 and if driven really hard, about 17/100. In the SL, the consumption is between 17-22/100 because I drive it very differently (and it is a lighter car than the w126)
interesting to note though.... in both of those cars, the transmission ratios are identical as is the final drive (2.47:1 - tall) and yet it is exceptionally well balanced between outright acceleration and cruising efficiency - something the Gwagen never was (arguably still can't - look at the 6.3 consumption figures these days) designed for anyway.

and the 2.02tonne RRC is right there with the w126 - while the 126 is a bit lighter, It's not about the weight. it's about the torque that the m117 v8 provides so low in the rpm band. and with the redline of 6500 (and believe me it will get there very quickly and easily) the spread of power is good. downside? fuel consumption.... it would probably end up being around the same 20L/100 as the 3.9 - but perhaps more importantly, the torque would be much better and the acceleration would make the car more driveable.

So yes, it's still theoretical still. But perhaps there are other engines which are cheap, reliable and have maybe 'better' fuel consumption and good torque figures, and are more suited to swaps...

And I still haven't contemplated the idea of different transmissions.... I'd like it to stay automatic, but certainly wouldn't rule out a manual..... it's simply going to depend on what is easiest to mate to the donor engine.

I think we'd all love a 7 speed semi-auto and a double low range, but i can't forsee that as being a viable proposition... I'd have to find some portals and a set of 35's to make something like that work..... and then how useful would the car be as a tow vehicle? hmmm

[Scouse]

To give you an idea of consumption..... I'm currently hovering around the 20L/100km without trailer attached and about 26-28 with. I do mostly highway work, and find that 4th gear is a waste of time with the trailer, except on flat pavement. It's actually not much different without the trailer in that respect, and I would opine that the 3.9 wouldn't pull the skin off a rice pudding when really trying to get it moving from 90km/h upwards. That includes kickdown etc. it just revs and doesn't accelerate, especially uphill where it even loses momentum under kickdown - especially at around 90-100km/h. If this is normal for an RRC, then fine, but I would expect some form of acceleration with the kickdown from 4th to 3rd (and sometimes 2nd?) when the momentum drops like a stone.If you're getting that sort of power/economy out of a 3.9, there's something seriously amiss. The air flow meter has been known to cause similar symptoms.

[Mercguy]

If you're getting that sort of power/economy out of a 3.9, there's something seriously amiss. The air flow meter has been known to cause similar symptoms.

The AFM is clean as a whistle and working fine. there's no nasty purging of unburnt fuel or smell of rich running, Afaik, it was chipped according to Wade/Stuart. It's been serviced at Graeme Cooper's for the last 11 years prior to my purchasing - just over a month ago. It has no idle issues.

I live in a hilly area on the south coast, not far from Baz (or you actually) and the 20/100 is what I was told to expect by other forum members, and I can live with that. Towing the boat down from Qld netted me around 28/100. I expected something in the vicinity. This model has no O2 sensors fwiw.

The reason for the contemplation of the swap is primarily to reduce the consumption and increase the torque / power output.

the M117 v8 is good for 220kW and about 410Nm and a fuel economy of between 17-22L/100 when being pounded hard. in the 2.6tonne Gwagen it gets 20-22 with the short final drives, so I expect a fraction better if I were to swap into an RRC. However, the OM606 will provide more torque and lower in the RPM range, and the 5 speed auto works well with programmable shift. The issue with an MB engine swap is the transfer case being divorced from the transmission, thus creating extra annoying issues. And if push came to shove, then I'd probably ditch the BW and go for a VG150 from a w463. All in all, by the time that was done, I'd probably have been able to buy a 460.... Conversions are never cheap things to undertake.

I do have an opcon MX422 twinscrew supercharger here, but somehow I do not think a 3.9 engine would take 10psi of boost without heavy modifications.

would provide the extra torque though.... :D

[Scouse]

The only time I've ever come close to 20l/100km is towing a loaded car trailer.
Normally it was around 14-15l/100km from my 3.9 RRC & never a complaint about performance - I reckon it'd leave our 4.6 P38 for dead.

[BigJon]

I like the idea of the viscous coupling, but understand the issues it comes with, but it's nice to have fulltime 4wd. an LT would obviously change that.


LT230 transfer cases are still fulltime 4wd. Just with a manually lockable centre diff, rather than a viscous coupling.

[Mercguy]

Yes, You are absolutely correct, and I was not very eloquent in my explanation of what I meant, and you have correctly explained what I didn't correctly explain. Thanks:BigThumb:

Yes, I was referring to the viscous lock-up versus manually locking.

I also see that the LT has options.... ratio options, ATB centre diff options...

I see this as a good thing. like the VG150 is also a good thing in the w463.

But the day before yesterday I started looking at the Atlas 4 speed transfer case and just ummed and arred.
double selectors and hi-lo really got me thinking, except it's missing the most important thing.... a torque biasing centre differential gear.

Sure, it has advantages (locking each output shaft separately) but it has 2 achilles.... like we do!

1. cannot shift the 4 speed on the fly (i.e. below 5mph rolling) as there is no synchro
2. no centre differential - rather the expectation is that it is for locking the output shafts only, and that means not suitable for bitumen use in 4x4 mode.

I cannot think about the effect that wind-up would have on the atlas, quite possibly it would be minimal, and the driveshafts would all simply explode one after the other? It does look like an absolutely ripping unit for 100% offroad use.

I wonder what it would be like in rwd only.... because everyone's opinion that I have read, is that the Range rover was designed as an FT4wd and as such, taking drive away from the front wheels results in horrible handling traits....

I sometimes wonder if people who say these things speak from experience, or if it is conjecture. Perhaps they never drove a manually locking hub vehicle before, or maybe they have experienced extreme loss of front end grip as a result of having only rwd, and being completely used to the behaviour of a FT4wd unit?

anyway, that's slightly OT, but still relevant.

Also starting to look in more detail at axles & suspension. I'm looking at 33" road tyres at the moment. would love 35's but do not see the value as I'm not heavily offroading it at the moment.

The diesel versus petrol argument has effectively been settled. While I'd love an OM606, I already have the m117, and know it's in fantastic shape. I'm thinking about gearboxes & transfer cases. I have a 4 speed 722.3, and know it would be fine as far as automatics go. final ratio is 1:1, so that leaves calculations for transfer case and final drive to be done, so optimal operating rpm can be established.
This is where the 33/35" tyre discussion swings in, to either hinder or aid in the final operating rpm.

I'm starting to think that Defender owners have the best of both worlds when it comes to modifications.

but an RRC with 35"MT Bajas would look kickarse. And if I did the v8 swap 'amg-style' with some side-exit pipes for ****s n giggles I think it would be a real laugh to drive.

I'm amazed at how much room there is and how little needs modification to make it all work... and it seems the weight penalty overall will be very little.

so it looks like I need to make some tough decisions on the transfer case and transmission. which means I need to work out what to do with tyres, which means I need to look at suspension / flares / lifts / axle assemblies...
geez. talk about biting off more than I can chew right now....

[loanrangie]

i found the UK site LR4x4 a video of a guy that put an OM606 and 722.6 auto into an F250 dual cab cab turbo/ intercooled and the thing hauls arse and returns 29mpg.
What engine is the M117 ?

[Lockee]

LT230 Transfer case as fitted to non Viscous Rangies is one of the best cases in the market with constant 4wd.

I would keep this and work around that as your base. Had one with a Small Block chev and TH400 in front of it in my 85 Rangie.

[Mercguy]

i found the UK site LR4x4 a video of a guy that put an OM606 and 722.6 auto into an F250 dual cab cab turbo/ intercooled and the thing hauls arse and returns 29mpg.
What engine is the M117 ?

V8 petrol engine.

You can find the details of the engines they manufacture here more easily than on the MB wiki (where you need to look up the vehicle models)


https://en.wikipedia.org/wiki/List_of_Mercedes-Benz_engines
Mercedes-Benz M117 engine - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Mercedes-Benz_M117_engine)

while I think about it, here's the spec for the om606:
https://en.wikipedia.org/wiki/Mercedes-Benz_OM606_engine

Basically the m117 engine designation started life as a 4.5L iron block alloy-head SOHC v8, and in about 1978 development prototypes converted it to alloy block and heads, and displacement increased to 5.0L. they were released into mainstream models in 1980-1
From there, in 09/1985 increased displacement 5.6L version was released, becoming their top-level offering for all petrol engined sedans until 1991.
AMG (were an aftermarket tuner at the time, not part of DBAG as they are now) made several performance versions based on the block - a 5.0, 5.4, 5.6 SOHC versions & 6.0DOHC version, early versions of which were rather 'fragile'.

The spare engine I have here is a high compression (euro spec) 5.6L v8 m117.968ECE basic spec:
bore/stroke 96.5/94.8
displacement 5547cc
compression 10:1
nom. output 220kW(300hp)/5000 DIN80/1269/EEC @1/min
torque 455Nm/3750 DIN80/1269/EEC @1/min
consumption l/100km:
city 16.8
90km/h 10.5
120km/h 12.7

I've found the fuel consumption figures to be highly accurate. I got about 17L city in the 560SEL (which this engine came from), but more like 22 in the 560SL (different spec engine and driving style)
On the highway - speeds between 100-140(ish) it returns 13-13.5L/100 without fail in both cars.
driving up twisty roads (like macquarie pass for example) with a lead foot still only nets about 19L/100 in hard driving.

The OM 606 has a couple of excellent advantages over the v8.

1. power is only slightly less in standard trim, and can easily be tuned to exceed the v8's stock figures.
2. is MUCH better on fuel overall, even taking the price disparity into account between 'ultimate' 98RON & 'ultimate' diesel.
3. more low-end torque. theyre just mental torque monsters... particularly If the turbo is better tuned, the power output increases significantly, without affecting reliability or needing any internal modifications.

then there's the intelligent stuff..... like no distributor or spark plugs, making deepwater crossings a little less problematic, simplified engine management when replacing the IP with one from an OM603 (no electrics to get wet)

And while the OM606 would be my choice, I already have the m117, which really makes the swap a bit of a 'no-brainer' except I'm leaning towards wanting an overdrive final drive in the transmission, rather than a 1:1.

the LT will need to be divorced.... as the 722 auto rear housing has no flange for a transfer case. so the VG150 may still be a simpler option.... I'll have to work it out more carefully with measurements underneath - because divorcing the transfer case means propshaft angle changes.... and I'll probably want to use CV's on the t-case rather than DC's....

[Lockee]

does the Rangie ZF Auto have ability to be updated to 6 Speed or similar to higher spec BMW Units of upgrades or would the 4 speed suffice

[loanrangie]

As fun as it sounds swapping in bigger V8 with the mods and engineering required would really put me off.
Was the 722 ever fitted to a G or ML 4wd ?

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[Mercguy]

As fun as it sounds swapping in bigger V8 with the mods and engineering required would really put me off.
Was the 722 ever fitted to a G or ML 4wd ?

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In a word, yep. all modern MB autos are prefixed with 722.
more specifically for Gwagen, the 722.3, 722.6 units favoured in w460/463.

722.0/722.1 hydraulically controlled 3-speed/4-speed 4-bolt 1969?1982
subcode-W3B 050 three-speed automatic unique to the 1975-81 450SEL 6.9
722.2 hydraulically controlled (fluid coupling) 4-speed 4-bolt
722.3/722.4/4G-TRONIC hydraulically controlled (TQ converter)4-speed 6-bolt 1981
722.5 5-speed (TQ hydraulically controlled 4-speed with additional electrically controlled 5th overdrive gear)
722.6/5G-TRONIC electronically controlled 5-speed overdrive (aka NAG-1 or W5A330/W5A580)
722.9/7G-TRONIC electronically controlled 7-speed automatic transmission
9G-TRONIC electronically controlled 9-speed automatic transmission

[Mercguy]

ML is a dirty word which should not exist in MB vocabulary.

[Lockee]

Blasphemy but if a ZF Auto can handle a V12 BMW wouldn't it be easier to adapt engine to the transmission and transfer that work in the vehicle?

[MR LR]

I don't know how similar/different Merc diesels are, but this thread may have something of interest in it for you, amongst all the typical Pirate BS and American crap.

OM617 Diesel swap.. - Pirate4x4.Com : 4x4 and Off-Road Forum (http://www.pirate4x4.com/forum/land-rover/852955-om617-diesel-swap.html)

[loanrangie]

ML is a dirty word which should not exist in MB vocabulary.

Yeah not a fave of mine either, if the 722 was fitted to a 4wd then possibly one might have a suitable flange.

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[Mercguy]

Blasphemy but if a ZF Auto can handle a V12 BMW wouldn't it be easier to adapt engine to the transmission and transfer that work in the vehicle?

I did some enquiring on this just a little earlier....

torque converter to suit the 4HP22 mated to the m117 will be in the vicinity of $2K.

Yes, you read correctly.
That is for a custom unit, correctly set to the optimum stall, which will bolt to the m117 flex plate and fit the 4HP22 front pump housing.
Obviously all the dimensions for the unit are one-off so it was never going to be cheap.

:(

[Mercguy]

Yeah not a fave of mine either, if the 722 was fitted to a 4wd then possibly one might have a suitable flange.

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yes, the 722.3 & 722.6 variants fitted to w460 & w463 Gelandewagen. also w461 g-professional & other steyr-puch creations using MB engines.

in all cases the t-case is divorced from the transmission.

[Mercguy]

for me it's more a question of maximising the efficiencies that can be gained via using the 722.6 5 speed unit, as opposed to a 4 speed.
yes it's added complexity. Some electronics, albeit a standalone fully-programmable shift controller - I'm not disagreeing on your point. the 722.6 was used reliably behind the 6.5L v12 biturbo amg, so it can handle the torque of a boosted OM606 or tuned m117 easily enough, and it's a bolt-up solution.

The secondary point of this exercise is to continue researching what will definitely not work post transmission - / what will break / what will be borderline in terms of driveline components.

I'll obviously have to ditch the BW in favour of the LT230. That much is a given, considering all the advice I have read here and elsewhere. Which is a bit of a shame, because I find that the BW as it is in this vehicle now to be very nice and smooth.
Apparently the 4HP22 isn't real strong in the torque dept either. so mating that to a turbo 606 possibly not the best idea, yet it may be able to take the 450Nm from the m117.

I do not know if the LT230 case would benefit from an ATB centre, but I would probably buy one in this configuration from ashcroft etc with the ATB centre already fitted, since I'm likely to have to ditch the BW anyway.
I don't like uni joints, and much prefer CV's, so there are some changes I'd make in the propshaft dept. This would be beneficial overall, especially if I have to divorce the case or use a VG80 or 150 - again, not ideal, but I have to process the requirements before I can analyze the costs and see if it is really worth it.

Then diff/axles/hubs.... again, there are too many options people bandy about - so I have no ****** idea what the best and most cost effective reliable option for an RRC is, be it wholesale axle housing removal or complete swapping of all internals, or simply remove and replace 'some' subcomponents to achieve greatness. I don't know if 24, 30, 33 or 35 splines are required, or even if they are worth the claims. I do know a little bit about axles, having snapped plenty of them in the past, but not in a 4x4.

The big issue is the longterm goal. Right now, it's a bit too vague, so I am trying to simply eliminate ideas on purely a 'cost vs benefit' basis.

I may never again even consider further modifications or additional repowering if I go OM606 and get it 'right'. But there are a couple of things in my way, one of them being this lovely v8 and supercharger and gearbox combination I happen to have sitting here.
The other thing in my way is wanting to do something more or less 'cosmetic' - and that is a larger wheel/tyre combination, without making the vehicle a pig to drive or uglier than a hat full of you know whats..

I think the diesel option is more intelligent, but the petrol more powerful (and better sounding).
The idea of 35" Claws under the arches has always appealed to me. Getting the suspension setup to achieve this in an RRC seems to be overly complicated compared to other vehicles. Or perhaps I have simply read too much.

Then there is the issue of combatting the extra drivetrain stress with the larger tyres.... tougher axles, diff ratio changes possible, fine spline hubs.... I really don't know enough about LR parts or specs to understand fully what will be OK as an interim measure or if the full-scale big dollar upgrades are required just to make a basic wheel diameter change..

This is one area where I obviously understand mercedes-land much better. I could tell you knowingly that a pair of gwagen axle assemblies are near enough to bulletproof, and to fit 35's no performance mods would be required other than ensuring everything is serviceable - and if it's not, then it's simply a case of overhauling/greasing the bearings/seals/swivels etc and get back on the road again.

But this is not a G, and I'm glad it isn't in many respects.

I think my biggest issue is that I have with planning it all, is that I see all you guys modding the monkeys out of your 110's 90's & 130's and discos and I get 4x4 envy. I'd love the RRC to be able to cross axle 90 degrees, but know it just isn't meant to be for me, yet part of me wants that articulation.


Yes, 35" tyres would be a desirable outcome, as would more torque.

if the 4HP22 could reliably live behind a 455NM 220kW 6500rpm screaming OHC mercedes v8, then all I'd worry about is the bellhousing adapter & the $2K pricetag for a custom torque converter to make it all fit and work properly.

If I must upgrade axles / diffs / hubs / cv's etc to make a set of 35's work, then I really need to cost it out in detail. It's probably the biggest modification to the vehicle I'll be making, so I want to get it right.

The engine stuff.... well the 3.9 is still in there plodding away right now, so I have time on my side to get all the extra details thoroughly sorted before embarking on the swap. It's only really the transmission / transfer case decision that will influence the engine choice. That will simply come down to costing the two options out in detail... which I've already started.

[loanrangie]

No hope of an lr zf lasting with anything more than a mild 4.6 ,shame about the divorced 722 but if it has a removable extension housing anything is possible.

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[Mercguy]

The rear housing on 722.3/4/5 units contains the govenor and speedo drive / hall sensor ring, and rear bearing.
the 722.6 has a much more condensed rear flange, however, it simply means less room to work with, as all the same stuff is crammed into a tighter space, with electrics. The main issue with that is the 722.6 actually has a longer case than the 3/4/5's. so while the rear housing is super short, the case grew in length to support all the internal stuff.

I'm not sure if any of the diesel guys out there have ever seen black smoke racing, but basically for the last 5 years they have campaigned various mb diesels in a w123 TE drift car, then later into other vehicles. The 123 was/is arguably their most famous car and they currently run an OM606 with about 7-800bhp. yes.... it's a bit mental. but behind it sits a 722.6 from the v12 mercedes and minimal internal modifications (extra clutches) and holds together well.

I had another conversation with the torque converter guys, and gave them some accurate figures from the last engine dyno sheet I had for the m117 and then factory om606 figures.
His response was 'marginal reliability behind the v8' and 'don't bother with it behind the diesel, use the benz tranny, it's f-ing bulletproof'

So now it's back to the drawing board, and time to examine how to fit an OM606/603a/722.6 hybrid and a divorced LT230 with ATB centre. I haven't thought to ask Dave Ashcroft yet about the acceptable torque ratings of one of his transfer cases, I'm sure he gets emails and phonecalls by hundreds of people about the same thing every day.

[loanrangie]

LT230 is strongest trans made by LR and will survive with only a little acceptable backlash at worst, divorced may present issues with the rear shaft but depends how much space you need.

[loanrangie]

This may open up some options -

722.6 Transmission For Sale (http://www.smartpartsauto.com/automatic_transmission_7226.html)

http://www.rakeway.co.uk/page12.html

[350RRC]

Merc..........

You might find this thread on Pirate interesting........

Slammin's RRC.... - Pirate4x4.Com : 4x4 and Off-Road Forum (http://www.pirate4x4.com/forum/land-rover/1094592-slammins-rrc.html)

The way they are thinking opens up all sorts of options, go to the end haha.

cheers, DL

[Lockee]

How will you go with length if divorced?

[Mercguy]

Good question.
I haven't been able to get underneath, we've had too much rain and last weekend I busted my right knee (lateral meniscus torn clean off) so can't get under to measure up accurately. Divorced or not, I'm going to be looking into some CV propshafts, rather than uni joints. The hope there is to get a more balanced propshaft, as well as a slightly enhanced articulation range, to combat any angle increase caused by the t-case separation.

But right now, a couple of things have become a little clearer.

1. transfercase separation and associated costs versus;
2. keeping the trans/t-case assembly and using adapterplate & custom converter


Believe it or not, the costs are not a lot different. The amount of effort however, is significantly in favour of keeping the existing 4HP22 & BW, and even allowing for a modded LT230 to be swapped in, should the BW fail.

If the 4hp22 fails however, it's almost a net $2k loss immediately on the custom converter, along with the cost of finding another good transmission.

as opposed to the following scenario, which I have loosely defined.

1. prep the 722.6 and investigate adaptor for rear housing to allow an LT230 to bolt-on directly - could be about 1k to machine a new rear housing. I would hope it would be a lot less, but i need to look into this in detail.
2. 722.6 requires standalone trans controller anyway (costs vary, but can be had from between 600-900au $)
3. cost of an LT230 - whether it's me buying 2nd hand and rebuilding myself, or just buying one outright which has been given the ducks nuts so to speak (ashcroft etc) so anything up to $2500 incl shipping & duty.
4. will need a driveshaft if the trans & tcase are divorced, and that means tcase input shaft /flanged / cv's / yoke etc... up to about 500 bucks depending on the cv costs.

There's a bunch more stuff to investigate, but for now I'm slowly working it all out.

I have not factored in the basic engine mount fab / exhaust header / sump mods at the moment. Those costs are something I always fully expected as bare minimum requirements. Right now, I'm trying to balance 'bang for buck' in the other areas to see what will give the best performance without being just a stupidly expensive exercise for little gain.

[loanrangie]

Best bang for buck would be BMW engine that used a zfhp22 box so only requires a bellhousing swap plus other conversion requirements.

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[Lockee]

Good question.
I haven't been able to get underneath, we've had too much rain and last weekend I busted my right knee (lateral meniscus torn clean off) so can't get under to measure up accurately. Divorced or not, I'm going to be looking into some CV propshafts, rather than uni joints. The hope there is to get a more balanced propshaft, as well as a slightly enhanced articulation range, to combat any angle increase caused by the t-case separation.

But right now, a couple of things have become a little clearer.

1. transfercase separation and associated costs versus;
2. keeping the trans/t-case assembly and using adapterplate & custom converter


Believe it or not, the costs are not a lot different. The amount of effort however, is significantly in favour of keeping the existing 4HP22 & BW, and even allowing for a modded LT230 to be swapped in, should the BW fail.

If the 4hp22 fails however, it's almost a net $2k loss immediately on the custom converter, along with the cost of finding another good transmission.

as opposed to the following scenario, which I have loosely defined.

1. prep the 722.6 and investigate adaptor for rear housing to allow an LT230 to bolt-on directly - could be about 1k to machine a new rear housing. I would hope it would be a lot less, but i need to look into this in detail.
2. 722.6 requires standalone trans controller anyway (costs vary, but can be had from between 600-900au $)
3. cost of an LT230 - whether it's me buying 2nd hand and rebuilding myself, or just buying one outright which has been given the ducks nuts so to speak (ashcroft etc) so anything up to $2500 incl shipping & duty.
4. will need a driveshaft if the trans & tcase are divorced, and that means tcase input shaft /flanged / cv's / yoke etc... up to about 500 bucks depending on the cv costs.

There's a bunch more stuff to investigate, but for now I'm slowly working it all out.

I have not factored in the basic engine mount fab / exhaust header / sump mods at the moment. Those costs are something I always fully expected as bare minimum requirements. Right now, I'm trying to balance 'bang for buck' in the other areas to see what will give the best performance without being just a stupidly expensive exercise for little gain.

The rover driveline is quite stout with the right operator. I have run a 305 Chev TH400 to an LT 230 with 36 inch tyres for a bush car with Mazidrive gear and a hypoid rear diff.

Std suspension with a mild lift also handles this.

I would do the engine to ZF Box.

[Vern]

220kw and 450nm, just build a strong 4.6!

[loanrangie]

220kw and 450nm, just build a strong 4.6!

Where is the fun in that.

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[350RRC]

Merc,

You should probably read this thread re: duck's nuts LT 230's.

I blew up my LT 230 at KOH and it took me out. - Pirate4x4.Com : 4x4 and Off-Road Forum (http://www.pirate4x4.com/forum/land-rover/1626818-i-blew-up-my-lt-230-koh-took-me-out.html)

cheers, DL

[Keithy P38]

Sorry to sound a downer here, but my 2c says your 3.9 has issues to be sucking that much juice and having trouble keeping the speed limit on highways with a baby boat on the back.

First thing I'd do is get it checked over (could be a simple case of lost compression)...

Second thing, you're planning on fitting a Merc donk that has an extra 1000cc over a 4.6 rover V8, yet only 30Nm gain, and at much higher rpm than the rover V8 puts max torque down... Sure, it's got 200kW compared to the 4.6's 155-odd, but who spends most of their time at 6000rpm anyway? You're towing up hills - logic says max torque at low revs is what you want. A towing cam in a 4.6 rover V8 will get you an easy 430Nm at a lazy 2500rpm.

Why go to the extreme and have to speak with an engineer over a Merc swap when you can go in-house and keep your box and transfer case!

My 4.6 towing 3.5t plus loaded to GVM only just touched 20L/100km... Your motor is in need of love.

Cheers
Keithy

[DoubleChevron]

I know someone that performance tunes cars who I was chatting about engine conversion too (with regards to range rover classic) on facebook. He sent me this dyno printout with the suggestion a bog standard LS1 is the conversion to go for if it can be done:

https://www.aulro.com/afvb/

Look at the difference. It's quite interesting the torque peak of the rover engine. That will be that work of art inlet manifold the later 4.6's have.

seeya,
Shane L.

[Lockee]

I know someone that performance tunes cars who I was chatting about engine conversion too (with regards to range rover classic) on facebook. He sent me this dyno printout with the suggestion a bog standard LS1 is the conversion to go for if it can be done:

http://www.aulro.com/afvb/attachment.php?attachmentid=91594&stc=1&d=1426051880

Look at the difference. It's quite interesting the torque peak of the rover engine. That will be that work of art inlet manifold the later 4.6's have.

seeya,
Shane L.

Interesting

[loanrangie]

There is no shortage of suitable engines but the problem is always what box to use that will handle the power and how much to adapt it to a rover tc or hassle to use another tc.
A 4HP24 might handle a stock LS1 for a while but plenty of right boot will kill it.

[Vern]

If someone made an adapter for a decent more readily available auto (not the 4l80e), it would open up a whole lot of options.

[Lockee]

6l80e

[Vern]

Or ford aod

[Lockee]

What motor from ford

[loanrangie]

What motor from ford

5 or 5.8ltr efi windsor :)

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[Lockee]

Bit old skool. 5.4 instead

[loanrangie]

Bit old skool. 5.4 instead

You wont get a 5.4 engineered.

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[Mercguy]

I can assure you there won't be any pushrod ohv engine going in as a replacement. ;) Otherwise I'd stick with what I have and drop the twinscrew straight on top of it as it is now.

[niall]

I can assure you there won't be any pushrod ohv engine going in as a replacement. ;) Otherwise I'd stick with what I have and drop the twinscrew straight on top of it as it is now.

dont knock the pushrods, ive had both a 350 chev and 302 windosr, very impressed with both.

these days LS1 seems like the perfect choice

[Mercguy]

I've had pushrod engines in the past. I moved on from General Masochism long ago. :D