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3.5 V8 Efi from a K-reg Disco

cappers

cappers

Trekker
Site Donor
Been offered a good running 3.5 V8 Efi from an early (K reg - 1992?) Disco, plus the LT77 box; not sure if it's a long stick or short stick - anyone know if/when they changed or were LS only used on early RRC?

I understand that if it's a long stick it'll fit a 90 without too much hassle as there are no tunnel modifications needed if using the existing 90 gearbox mounts. Prop-shafts remain the same as well, as does top hose, bottom hose, standard exhaust and V8 fan cowl.

A short stick will mean cutting the seatbox etc. and the gearstick ends up just at the front edge of the seat box.

If the box is no good should I just get the engine and hunt around for an appropriate box or get my squat bellhousing LT77 (4cyl 2.5 petrol) modified. I don't really want to bodge seat boxes etc and would like the V8 to drop in where the LR Godz designed it in a 90.

Any thoughts most appreciated please (yes I know there's probably 100s of posts about V8 conversions but I haven't time to search through what often appears to be conflicting opinions!).

capo
 
It appears that there are several gearbox options for a V8 in a 90, so any thoughts on practicality, availability, and do-ability would be most welcome:

1. R380 from Ashcroft (all the latest/greatest internals) with a V8 bellhousing/input and a Defender tailcasting/shifter. It all fits with everything in the right place, with a proper V8 clutch and no mods to fit anything. It's the expensive route, but it cuts out a hell of a lot of messing around both at build time and when servicing.

2. LT77 gearbox from a circa. '85 R/R or an early (1989-????) V8 disco, the gear stick configuration is the same as a 90 so no tunnel modifications needed if using the existing 90 gearbox mounts. Prop shafts, top and bottom hoses, exhaust and V8 fan cowl remain the same. Sit the R/R V8 engine mounts 1.5" further back than fitted on the R/R and the engine/ gearbox will drop in.

3. LT77 from later Disco or later RRC will go in a 90 or 110 but it's a "short stick" gearbox and the gearstick ends up just at the front edge of the seat box. Could cannibalise the 90/110 2.5 LT77 box and swap top housings/linkages etc.

4. V8 auto Disco should just drop in - the Disco V8 auto, Disco V8 LT77, and 90/110 LT85 are all the same length. But the Borg Warner chain drive transfer box that's usually mated to the auto box has a shorter front output flange so will need a different length drive shaft.

Ta very much.
 
I didn't think Discos ever used the long stick gearbox. I had an early 2 door G reg and the gear stick was much as I'd expect the later RR to be - nothing like the long stick RR I can vaguely remember. I also recall some in here saying that it's possible to swap gear linkage parts if you already have an LT77 in the 90 and convert the Disco V8 box to fit.
Other than that, I think you are spot on.
 
SimonHobson said:
I also recall some in here saying that it's possible to swap gear linkage parts if you already have an LT77 in the 90 and convert the Disco V8 box to fit.
Click to expand...

o_O I've been told so many things, often conflicting, about such a conversion!

Any more about the above ? the LT77 is up for grabs too; the guy was going to replace the LT85 in a 90 but he decided it was too much bother and refurbed the LT85.

Edit; on re reading do you mean my 4 cyl long stick short bell housing LT77 mating to the 3.5?
 
I meant using the V8 LT77 from the donor vehicle, and swapping in bits of your current LT77 to convert the gearstick/selector arrangement. I can well believe that it's possible, but I've never looked at doing it.
An alternative would be to use your current box, and swap in bits of the V8 box to convert the front end to fit the V8. Again, I suspect it's doable, but never looked at it.

Some time perusing the parts catalogue and seeing which bits are common and which are different between the two variants might shed some light.
 
Long stick RR were typically fitted with the LT95
To replace the input shaft on the R380 with an input suitable for a V8 means dismantling the entire box. Unless the LT77 has a different method of fitting the input shaft. On the 380 everything behind the input shaft has to come out before it can be removed.
I have the manual for the 380, I will have a quick shufti at that, see if it is possible to replace the selector/stick arrangement without further surgery. I know it is not a 77 but they are basically the same housing.
Thinking about it for a second, it must be possible because my One_Ten V8 has the R380 from a disco 2 in it
 
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Decided to go for for a ZF4HP22 / LT230 with all the bits; one seen and price negotiated.

Coming up next, Capo's 2.5P manual 90 conversion to 3.5V8 auto 90.....it will be done by a very good LR garage down here so will only have 'after' pictures.
Not sure when but hopefully within a month or so :D
 
Nice. I am glad I went for a 3.9, but soon should assemble the 4.6 replacement, but mine is a 110 so a bit heavier. Are you going to change to the Disco 1.22 or a 1.410 transfer? I have disco boxes in both mine but will be changing back to 1.410 in the v8
 
Big Sandy said:
Cool! Bet you can't wait!
Click to expand...
Bit of a sucker for V8s and getting another one or converting mine has always been on the cards.
Seen a video of it running- sweet no funny noises smooth revs with a nice exhaust burblešŸ˜›
paul c said:
Are you going to change to the Disco 1.22 or a 1.410
Click to expand...
On 235.86r16 so should be ok with the 1.4box from the 90 - Disco had BW anyway and I want the lt230.
šŸ™
 
A bit of a cheat getting a garage to do the swap but as mentioned before I haven't the time, space, tools and experience to do it myself.
All in, and unanticipated problems aside, should come in at about 3K for engine, box etc. and labour. Considering I was contemplating spending 9-10k on a factory original, my 90 was 4k plus 3k for the conversion still comes within budget.
Off to do some work as I've spent too long fantasying and arranging V8 stuff!
 
Was going to ask this in your wanted ad, but thought here would be better.

Okay, now you have all the bits you need and are ready to proceed, when is it all happening? I'm looking forward to seeing the progress and finished article.

We may also need a photo of your good self, with that V8 grin installed too... :)
 
Booked in for w/b Monday 16 April. Engine delivered yesterday, gearbox Weds 12 and the 90 plus bits and pieces going in on Friday 13 šŸ˜Æ Estimated 3-4 days...
Before and after pics šŸ‘ And I'll ask Phil if he can take any of interesting bits such as mods, adaptions etc
You wouldn't want to spoil a picture of a Landy with me in it !
Be seeing you šŸ‘Œ
 
Just dropped off the Landy at Chichester4x4 and met Phil and team. In the middle of putting together galv chassis for another v8 conversion. There was a ex 2.5TD 90 and owner there with a 3.9 auto with Edelbrock carb all done by Phil; very professional, neat and in the correct place. Chap gave me a lift to the station in it and it was great! He said he uses no one else, Phil is an expert on V8s and Landys in general and a perfectionist too so the job will be done properly. They're a bit behind so not expecting to hear anything until next week.....tenterhooks or what! :whistle:
 
I chatted to one of the guys working on the chassis rebuild, he was pulling out what looked like new brake lines in the engine bay. I asked what he was doing and he said Phil didn't like the layout of the pipework and told him to redo them :oopsy: "Phil's like that" he said, "if it ain't perfect he'll do it again"
I like that ethos :thumbsup::thumbsup::thumbsup:

The chap who gave me a lift in his 3.9 auto 90 ragtop couldn't sing Phil's praises enough. We pootled along some B roads then slowly in traffic on an A road through town, so far nice and smooth, nothing breathtaking, then we joined the bypass and he opened up :D That deep V8 growl and pushback in the seat bought butterflies to my stomach and a grin to my face :rofl:

I am now going to (or will be trying to) stop thinking about V8s and get on with life. Two lecture slots take up most of tomorrow, then two days out on the University of Southampton National Oceanographic Center's survey vessel with half a dozen students doing coastal sedimentology. I know nothing about the topic, only there at the invite of a colleague and mate who does and my role is crowd control. The NOC staff do most of the teaching anyway so it a couple of easy days in what looks like sunny calm seas :cool: So as not to feel guilty I'll take some anoxic sediment samples back to the lab as there might be some bugs of interest there (I look for antibiotic resistant strains in human influenced environmental niches).

Time to put this thread to bed. I'll post a new one about the conversion once it has been completed. :thumbsup:
 
Old engine and box out ready for the V8 and ZF and have the first hiccup....auto-box doesn't appear to have the ring gear plate and boss to connect the box to the engine :thumbsdown:. Contacted the seller and await a reply...wonder if it went with the engine which he sold separately.
If no good news, has anybody got a ring gear plate and boss to mate a 3.5V8 to a ZF4HP22 box?
Might have to phone Dave Ashcroft.
So it goes.....:whistle:
 
Emailed him and will phone in the morning to check; seen exactly what's needed on the bay, not cheap and will hold things up for a week :crying:
I'm hoping the ring plate, spacer, boss and bolts were amongst all the bits he delivered and have just been mislaid... ever the optimist :whistle:
Stand by for the next thrilling instalment of Capo's Conversion on the road to Chichester...
 
Phew! :) Starter ring etc still on the original engine! Being removed and will be sent ASAP :thumbsup:

auto starter ring.jpg
 
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