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ThreePointFive

4.0 GEMS engine swap

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Good day,

This will come as a surprise given my user name and signature, but I have a 3.5L V8 in my 90.

This is a factory fitted engine and has covered the 167000 miles the vehicle has done. I'm taking it out of the vehicle as it's being rebuilt, and it makes sense to do the engine too. It's not got any specific issues, but I think generally it would be worth the attention. I have noticed a significant amount of black/brown gloop in the top of the oil filler, so it needs a look.

My question is, having heard the figure of about £1k, is that an useful estimate for a rebuild of an engine in average condition? I know this is based totally on the condition of the engine, and as such could have any number of unknown issues.

Would it be a better use of funds to just let it continue running as is, and wait for something to fail before looking at my options? The vehicle rebuild is to a high standard, it makes sense that the engine should run as well as possible.

Lastly, does anyone have any suggestions of where to get this work done? Preferably in the south west. I can't do it myself as I don't have the time or skill in addition to the rest of the work.

Any help appreciated.

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Matey (John?) at V8tuner knows his stuff, don't know how much change you'd get from £1k whatever you do as you're into a fair chunk of money just to buy decent parts if you're doing it properly.

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The cost will depend on the condition of what you find when you open up the engine. At that sort of mileage I'd be considering:

Crankshaft regrind

Cylinder bore/hone.

Knock out all core-plugs, hot-tank the block and replace core-plugs.

New bottom-end bearings (big ends/mains)

New oil-pump

New camshaft sprockets, chain & tensioner

New camshaft bearings

New camshaft and followers

New spigot-bearing

New piston-rings

Check con-rods for straightness.

Check pistons for ovality & wear. Replace if in doubt....

Core-plug-removal and hot-tanking of both heads.

Check head faces for straightness

Replace all valve-guides

Replace exhaust valves (inlet valves will probably be OK)

Replace all valve-springs

While the heads are off, if the exhaust-manifolds are retained using studs this is a good opportunity to replace the studs too:

This little lot will set you back a lot more than £1K but it'll at least mean your engine will be fit to last another 167000 miles !

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Interesting reading and certainly glad I asked the question.

It looks from what I'm hearing, both here and elsewhere that it's more like £2500+ to pay someone to do it. I can't do it myself and it would defeat the object to end up with an engine which I cannot guarantee has been bolted together properly.

I have done some searching and in the opinion of many it seems the 3.5 is not even worth the effort - a viewpoint I find harsh especially if the aim is in part to keep it original. There are a lot of 3.5s around for not much cash, but the mileage, condition and even the legal ownership of the engine can't be verified. I don't want a 'hot' engine, in any sense of the phrase... All that, and for something that could be in worse condition than mine.

So I am left with two options - buy an RPI engine and deal with a seriously hard question of trying to justify £3,500 as a percentage of the vehicle value. Or keep it going as it is, and wait for it to go bang. Not much point to that in my opinion, if it's half way up the Alps or somewhere else where a 'game over' failure is just going to suck. I don't see a satisfactory outcome to this problem.

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While I'm no expert on V8's I think what Tanuki is saying is very true. I think for sure you should be dropping the sump and inspecting the crankshaft, and the main and big end bearings. There's a lot to be said for leaving well alone if it's working, but there's also the case or preventative maintanence.

I have a 'spare' 200 TDi at the moment. Its intended for my project 109. It's done a lot less miles than the one in my 88, but it will be having the head off and sent away for rebuild before it gets used, it will be having re con injectors and pump before it gets used, and it will be having all the pistons our for inspection, dealing with the bores and bearings as I find appropriate.

All before it ever sees fuel, just because I want the 109 to go on the road, and stay reliable on the road for 2 years with minimal work, thats my target.

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FFS don't buy an RPi engine.

Realistically the 3.5 is not worth very much, if it goes "bang" it's about £250 to plop another one in.

They are not complicated beasts to rebuild, in fact they're pretty damn agricultural. If you want to do a full Bull Bar Cowboy or Nige-style build then you're into £1k of parts, but for a bit of a freshen-up on a known-good engine you can do a few smaller things to make it nice.

At this mileage I would be looking at doing the cam, lifters, timing chain as they'll be shagged out, and maybe big-end bearings. On a budget, putting a 3.9 cam in, decent lifters & pushrods, and a duplex chain kit plus the gaskets is going to set you back a few hundred quid and a weekend with the spanners. For a few more pennies, a stump-puller cam will give it more low-down grunt. That aside, I'd just keep doing oil & filter at regular intervals and it'll probably last another 100k.

If you're doing a proper rebuild, freshening things up like fitting a new clutch, rad & water pump & hoses, genuine plugs, leads, rotor & cap is not glamorous but should give a factory-fresh lifespan to a few critical components. That and actually checking & tuning up the carbs & ignition.

Another option: Leave it alone, buy another engine, put it on the bench and take as long as you like building a really nice engine to swap in at a later date.

On top of any of this is the suggestion of fitting Megasquirt as that brings a load of benefits, on a 3.5 it would add maybe 25hp and a load of driveability, plus waterproofness and better MPG. But MS can't fix a knackered engine or bald cam, so start with the basics.

Very cheap option: Buy a valley gasket, lift the inlet manifold off, take a photo and post it here so we can see what it looks like inside.

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I overhaul industrial gas engines for a living and the rover V8 is an absolute doddle to work on compared to them.

If you are having any trouble with any particular aspect of rebuilding your engine there will be plenty of people offering you their knowledge on this forum, in order to get you on the right track.

Buy a decent torque wrench, a D.T.I. and some plastigauge for checking bearing clearances when rebuilding.

A rebuild manual can be found on a PDF on the Internet, which will give you all your tollerances, torque figures and sequences.

It's satisfying to rebuild an engine, but it might be worth buying a lower mileage larger capacity V8 to replace your 3.5 like a 3.9 or 4.2 or even a 4.6 :)

You could even buy a cheap 4.0 or 4.6 off E-bay then part ex it for a rebuilt short block from the likes of V8D which will cost around £1750 for a top hat lingered block, new/reground crank, new cam with followers, re-con rods and new pistons all built up and then fit your heads, sump etc. for a powerful reliable motor :D

I would not pay £3500 for a 3.5 V8 no matter who built it!

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I overhaul industrial gas engines for a living and the rover V8 is an absolute doddle to work on compared to them.

I understand how coming from that direction, the V8 would be simple. But I am coming from just above the "what's an engine?" level of experience! I don't have the time - my rebuild is taking too long as it is - facilities, or skills to do it. It makes more sense to pay for an engine or have it rebuilt by someone else as the cost in my own time will be much more and spread out over months. I need something which means the engine is sat in the chassis in the next month or so, as it's starting to hold everything else up.

With a carb 3.5, what engines would my ancillaries swap with? My understanding is that only a 3.9 will work, anything larger requires different parts.

I am looking into the feasibility of buying a 'long block' engine, but that means I'll still need the other parts.

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I think I'd rather go up the Alps with your current engine than an RPI one. Most comp safari Rover users use Rolland Marlow.

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would it not be feasible to drop something in from a d2 era, there must be a fair few of those kicking about.

did you sort the plug on yours?

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Doing a basic freshen-up on a budget should be well within bounds for any competent LR specialist, rather than going the ££££ new/recon engine route.

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FFS don't buy an RPi engine.

Realistically the 3.5 is not worth very much, if it goes "bang" it's about £250 to plop another one in.

They are not complicated beasts to rebuild, in fact they're pretty damn agricultural. If you want to do a full Bull Bar Cowboy or Nige-style build then you're into £1k of parts, but for a bit of a freshen-up on a known-good engine you can do a few smaller things to make it nice.

At this mileage I would be looking at doing the cam, lifters, timing chain as they'll be shagged out, and maybe big-end bearings. On a budget, putting a 3.9 cam in, decent lifters & pushrods, and a duplex chain kit plus the gaskets is going to set you back a few hundred quid and a weekend with the spanners. For a few more pennies, a stump-puller cam will give it more low-down grunt. That aside, I'd just keep doing oil & filter at regular intervals and it'll probably last another 100k.

If you're doing a proper rebuild, freshening things up like fitting a new clutch, rad & water pump & hoses, genuine plugs, leads, rotor & cap is not glamorous but should give a factory-fresh lifespan to a few critical components. That and actually checking & tuning up the carbs & ignition.

Another option: Leave it alone, buy another engine, put it on the bench and take as long as you like building a really nice engine to swap in at a later date.

On top of any of this is the suggestion of fitting Megasquirt as that brings a load of benefits, on a 3.5 it would add maybe 25hp and a load of driveability, plus waterproofness and better MPG. But MS can't fix a knackered engine or bald cam, so start with the basics.

Very cheap option: Buy a valley gasket, lift the inlet manifold off, take a photo and post it here so we can see what it looks like inside.

I must have missed this first time round.

I get that 3.5s are cheap, but they're also trash for that money. They'll be unknown and come with their own problems. A reliable 3.5 of known condition (and origin) is worth they money to me. Looking at ebay I am having some serious doubts there is anything I would benefit from above what I already have for that sort of money.

I would be quite happy to buy a 3.9/4.0 and run that as a temporary to get it on the road - but getting one that will drop straight in is the issue. They might be cheap but they aren't easy to get hold of. Every one on ebay seems to be listed with an issue of some type.

What is the reason for the RPi opinions? Seems they don't have too many fans.

I want to do a worthwhile rebuild, which may not mean £1k of parts but it still means a lot of work. I don't have the facilities to take an engine to bits and I can't work on it daily, I would be looking at 8 hours a week, not enough. This is why it's worth me getting someone else to do it, if I do go that way. It's also what takes it to a £2k+ rebuild.

I will be putting new clutch, plugs, leads, coil, rotor arm on it, that's a given. But I don't think that will really get to the depths of the mechanical issues that could be working away in the engine, it'll just make the most of what's left.

I think the thing for me to do is as you suggest, take the valley gasket out and have a look, and drop the sump. I can at least get an idea of what is going on and hopefully from that decide on my next course of action. Regardless, I will have to find someone/somewhere to do the work, so this will only partly help but it's better than nothing.

I have talked to the major suppliers of V8 recon engines and engine rebuilds, helpful to various degrees, I'll keep my options open though as the answer is universally "how long is a piece of string" when it comes to price. I don't like the idea of giving them a blank cheque while it's in bits on their bench, I want to know what I'm getting into.

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I rebuilt a 3.5 once.... Learnt a lot.... spent a lot..... still didn't have anywhere the same power as the 4.2 that i then bought (complete RR LSE for £500) and hasn't needed a rebuild.

G

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Just been in Martin Toole's workshop (Range Rover Recycled Parts), he has a pair of late V8's which are decent, one factory recon 4.0 complete, one good 4.6 block & heads & front (he'd have the rest in bits too).

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That's great, do you know what prices he'd be looking at?

I'd be interested in the 4.6 but none of my ancillaries will work with it if it isn't complete.

just to give an example of the "fun" I am having trying to source a decent engine - when you ask a seller a number of questions including the mileage, and they answer every question except the mileage, you make your own conclusions.

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I can also vouch for Hamlyns in Bogwater (much better sounding than Bridgewater!). They did a fantastic job on my series 1 engine.

If I were you I would get a 3.9 bottom end (9.35 CR), a 3.9 or 3.5 EFI cam and have that rebuilt using all your induction (assuming you have SUs) and other ancillaries and you would have a good reliable motor with a healthy grunt increase without stressing anything.

Which ever way you go, good luck.

Toby

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Thanks David, I have sent them an email and will see what comes of it.

I have a few options now to explore in terms of replace while I rebuild or just straight rebuild, once I have got the prices of all this I'll be able to make a decision.

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It been about 8 years since I owned a V8 classic range rover. That one came with a blown head gasket but I didn't know what I was buying at the time, hindsight is a great thing.

Anyway, I found a garage in Swindon, can't remember the name or location but I do remember this:

Three days labour

Two heads off for a skim

16 hydraulic cam followers

Thermostat

Oil

Anti freeze

£400

Never missed a beat afterwards.

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