Odd thought. Backdate a LR Disco 2 engine to improve reliability?

OK, so here's an odd thought.  Can you backdate a 4.6L Land Rover to the earlier 4.0L engine?

The classic Rover/Buick V8 is, despite it's many detractors, a great basic engine.  It was known as the SBC of the UK for decades as it provided a cheap, light, powerful (by UK standards) engine that was put in anything and everything.  The thing is to stay competitive in the OEM landscape they started stretching it and stretching it.  first to 4.0 then 4.2, 4.3, 4.4, 4.5, 4.6 and even 5.0L versions were made.  By the time they were making the 4.6L version for Land Rovers and the like it had been stretched as far, and possibly beyond, it's practical limits.  Add in the deteriorating condition of the patterns, and hence the molds, were pretty worn.  Slipped liners etc are 'common' on the post 2000 engines.  These engines supposedly made 217hp and 300lb/ft.  The earlier 4.0L engines made 180hp and 230 lb/ft.  Now I know it would be a step backwards, but is it worth considering dropping one of those engines in to replace a dead 4.6?

Further, is it possible to take a 4.0L and do a few minor things to get back some of the lost hp/tq such as a mild cam, head skim (or is the compression ratio already high enough for those combustion chambers?) etc?

Just thinking out loud right now.

BTW, to head off the 'drop an LSx in it' I did look into that idea.  Adapters do exist, but while it is possible, it's not practical.  The issues of getting the engine to play nice with the auto trans plus the rest of the body control systems is not easy.  If you swap the trans to suit the new engine you still have transfer case issues etc.  I have not found a single successful write up.  There was a company supposedly offering turn key LS conversions starting at $9K plus the engine and the base vehicle and I couldn't find proof they'd actually made any.  Yes yes you can start shouting MegaSquirt and other solutions, but that's way beyond what I'd ever even dream of taking on.

BTW, in case you haven't guessed i may know of a nice D2 with a dead engine.

The 4.0 was no better than the 4.6 in lifespan. The 3.9 would be a major wiring and computer project as they are completely different injection and ignition. Could you dress a 3.9 (or 4.2) with 4.6 manifolds and front cover? Maybe.  If to works you'll have a gutless pig with a big appitite for premium gas.  Look for a clean LR3.

Way back date

Says Olds engine, but if it's aluminum that would be a Buick.

Ok learned something new, Oldsmobile make a version of the 215 also, with different heads.

How similar is the 215 architecture to the later 300/340/350 iron block Buicks? Would one of thosebolt in?

Gearheadotaku said:

. Could you dress a 3.9 (or 4.2) with 4.6 manifolds and front cover? Maybe.  If to works you'll have a gutless pig with a big appitite for premium gas. 

This is what I was thinking of doing.

Gearheadotaku said:

Look for a clean LR3.

Quit the common sense approach.  This is an idea for a 'while you're out of work' project on the 'cheap'  LR3, or more likely LR4 would be part of my 'once I have a job' plan that involves actual, real $$'s not pocket lint and whatever the couch can throw up.

As far as I know all the BOP have the same bolt pattern.  I have done a few swaps, diesel to gas, V6 to V8, buick V6 to Olds 455.  Just decide how much room you have and how much torque the drivetrain can handle and choose accordingly.    I don't know if Rover changes the bolt pattern, I have to assume they did or all the dead discos would have 3.8 series two's in them.

It's nothing to do with bolting an engine up.  That's easy.  IT's making it work with the trans and the rest of the car.  That's why I was talking about older Rover units that you could bolt the existing ancillaries, and most importantly engine management system.

In reply to Adrian_Thompson :

....and that's why I wondered if one of the iron blocks would bolt up to all the Rover bits. Swap in a short block and retain the rest of the Rover ancilleries and heads.

I know of a disco 2 running a 4.0 block with 4.6 heads etc.  It is being daily driven

DeadSkunk (Warren) said:

In reply to Adrian_Thompson :

....and that's why I wondered if one of the iron blocks would bolt up to aall the Rover bits. Swap in a short block and retain the rest of the Rover ancilliaries and heads.

Now I understand.  Well the great Wiki-of-the-pedia says that at least the original 300 used the alloy 215 heads and intake initially.  BAsed on that I ASS-U-ME that all of them can interchange heads and bits.  I bet the front end of the engine is different though.  What did these last come in?

akylekoz said:

As far as I know all the BOP have the same bolt pattern. 

BOP?

fiesta54 said:

I know of a disco 2 running a 4.0 block with 4.6 heads etc.  It is being daily driven

tell me more please.

The last Buick V8s were around 1980, or so. BOP stands for Buick-Oldsmobile-Pontiac transmission mount bolt pattern. They're different from the Chevy small block pattern.

In reply to DeadSkunk (Warren) :

The Rover guys call it the BOPR bolt pattern, that was a new one to me.

I passed on a super nice, as in everything still works and perfect paint and interior.  It had the cylinder liner issue, maybe someone should stock up on iron short blocks if it's an option for saving a nice truck.

In reply to Adrian_Thompson :

I'm sure you know this already, but the 4.0 has the reputation of being worse than the 4.6 when it comes to the cylinder liners in the UK, whereas it's the other way around over here. If you're pulling engines already it might be worth just popping open the 4.6 and check if the cylinder liners are OK and slap some new head gaskets on if the liners are OK as those are a consumable anyway.

I've only seen a pic of the car in question.  The story was it was a nice Southern car that was bought over the internet up here in Michigan.  IT sounds like the poor owners were royally screwed by the seller.  I believe they paid for it, got it here and it didn't run correctly.  They spent indecent amounts of $$'s here trying to get it to run before parking it.  It was then purchased by the current owner for spares at fractions of a penny on the $ compared to what was spent.  The only attraction, beside the fact I love D1 and D2 Disco's is it's a cheap southern (NO RUST) car and i have time.

Did the current owner hint at to what he thinks the issue is?

I'm right with you regarding liking the D1/D2 Discos, I think one of these days I might end up buying a driving one. Nearly bought a TD300 equipped one in the UK once, but the eBay bids on it went nutsier than I was willing to accommodate.

In reply to BoxheadTim :

Wish we’d got the TDi here. 

In reply to Adrian_Thompson :

Aren't the early ones getting close to being importable? Not sure I'd want one that's been driven around muddy farms in the UK for 25+ years, though.

fiesta54 said:

I know of a disco 2 running a 4.0 block with 4.6 heads etc.  It is being daily driven

tell me more please.

I need to get Tjones_W123  to jump on here again

Ok, sorry to thread-jack here, but you mean to tell me a Buick v6 can be bolted to a Rover v8 transmission?

This holds ALOT of interest to me. 

Edit: nevermind.... My excitement was short lived. Holden used the gm fwd bell housing pattern on the Buick derived v6's in Commodores. 

All Disco’s should’ve come from the factory with Fords 300 I6...

Is pinning the liners still a thing or has that become to costly? I know machine work is going up. I love rovers, I think that they have interesting quirks and the motors are fairly simple. I just hate all the cheap plastic that is impossible to replace. I’ve still got a few things kicking around here and I haven’t had a rover in a few years. 

In reply to grover :

Yes, there are fixes for the liners, but some of the issues are due to the age of the tooling.   Also we've been so lulled into cheap prices from small block Chevy's and Ford's with parts made is such quantities that parts are amortized over such large volumes, even for after market parts, that prices are dirt dirt cheap to rebuild and upgrade.  The Rover engines are such low volume in comparison they are costly to rebuild.  

that's true, but with roverland and roversnorth still kicking at least there is still a market.  Having publications like alloy + grit around probably doesn't hurt either.  I'll likely own another classic rover of some ilk again, they're just neat little cars.  Might keep a defender on the farm in TN. 

I'm not sure the 'BOPR' pattern is actually all that common (compared to other american v8s). Earlier buick 'nailheads' do not share the pattern as I understand. It's really just a mid 60s to 1980 pattern. Other than contemporary 'BOP' RWD v6's I would be surprised if any of the other much more robust and common GM v6s use the pattern.