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what could it cost?


MarkieB
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so, as my wife keeps suggesting we should own a 'proper car' I'm looking at mid-late nineties V8 discos/rangies on Ebay

Trouble is, being Ebay, a few are bound to have the later V8 overheating symptoms; as I understand it from rpi, it's the cracks in the block for 3.9/4.2, slipping top hats/ sticky valve guides for 4.0/4.6

is one group of engines cheaper to fix than the other? I tried a search although couldn't think of many obvious search terms

one more question, is 3947cc a 3.9?

cheers

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so, as my wife keeps suggesting we should own a 'proper car' I'm looking at mid-late nineties V8 discos/rangies on Ebay

Trouble is, being Ebay, a few are bound to have the later V8 overheating symptoms; as I understand it from rpi, it's the cracks in the block for 3.9/4.2, slipping top hats/ sticky valve guides for 4.0/4.6

is one group of engines cheaper to fix than the other? I tried a search although couldn't think of many obvious search terms

one more question, is 3947cc a 3.9?

cheers

Hi,

My 1993 RR had the 3.9 lump fitted, when it suffered from the cracked block syndrome, mileage was 71000 with FSH. I priced all of the different options, new block, recon engine etc. I ended up buying a new 4.6 short motor from RPI, fitting the heads of the 3.9 all ancillaries etc. I also had the ecu chipped by RPI. Total cost about £1700 -£1800 this included all the gaskets , followers etc. (Land Rover £3000 for a recon engine).

Now done about 40000 miles absolutely perfect goes like brown stuff off a shiny thing, is absolutely superb as a tow vehicle with the extra torque.

The slipped liner syndrome should never happen as they are "top hat" Liners in the 4.6. Its also more economical than the 3.9, still not ecoinomical but hell you dont run a 4.6 because its cheap.

As for price as which its easier to fix its really the same cracked block/ slipped liner still amounts to the same thing new block or engine required.

Regards Keith

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You can pick up a running 3.9 for around £250, as far as I'm aware they are actually very strong and do not suffer anywhere near as much as the 4.2/4.6. If it goes bang you can either upgrade to 4.6 (I would get a top-hat linered block from ACR or Turners and bolt all the 3.9 stuff back on) or drop in a 2nd hand 3.5/3.9 for a few hundred quid. You could build up a pretty decent 3.5/3.9 (nice cam, uprated bits, MSEFi) for not much.

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Yeah Thats why it was the 3.9 in the disco but 4 ltr in the 50th 90. Same engine

As far as I know the change from 3.9 to 4.0 was to indicate engines using the Thor inlet manifold, i'm probably wrong tho - it was way before my time :rolleyes::lol:

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The only common things about the 3.9 and 4.0 engines are the bore and stroke dimensions and the number of cylinders. Virtually every component is different in some way, and may or may not fit/work in the other engine.

Consider;

Block, cross bolted mains and sensor mountings

Cyl head, chamber capacities

Crank, long or short nose, bearing size

Timing cover, oil pump

Distributor, used or not

Fuel system, Hotwire or GEMS

No Land Rover factory block is fitted with top hat liners, it is always an after market option.

The most trouble free version is I think the 3.9 serpentine intermediate as used in 96-98 Disco or stick with 3.5s.

jw

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As far as I know the change from 3.9 to 4.0 was to indicate engines using the Thor inlet manifold, i'm probably wrong tho - it was way before my time :rolleyes::lol:

Just to confuse things there was a 4.0 in the NAS vehicles (and I thought in the P38a Range Rover?) which had (I think) the GEMS injection system not the Bosch Motronic one fitted to the Thor engines.

AFAIK all are 3947cc though

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You can pick up a running 3.9 for around £250, as far as I'm aware they are actually very strong and do not suffer anywhere near as much as the 4.2/4.6. If it goes bang you can either upgrade to 4.6 (I would get a top-hat linered block from ACR or Turners and bolt all the 3.9 stuff back on) or drop in a 2nd hand 3.5/3.9 for a few hundred quid. You could build up a pretty decent 3.5/3.9 (nice cam, uprated bits, MSEFi) for not much.

that does make it sound more feasible — after Keith's pricing up I was tending towards a tdi, although V8 is my preference really — so from £300 to £1300 according to how tight the budget is at the time [+ shipping]

I suppose a professional vehicle inspection is in order whatever happens when there's a risk of that much additional cost

cheers

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that does make it sound more feasible — after Keith's pricing up I was tending towards a tdi, although V8 is my preference really — so from £300 to £1300 according to how tight the budget is at the time [+ shipping]

All the V8's are pretty much interchangable, you can bolt anything from 3.5 on carbs to 4.6 on Thor EFi in the hole in the front so if the worst comes to it you aren't staring down £2k for a new complete 4.6. The engine problems (or potential for) could be a good bargaining chip with a seller, especially if the engine is making any noises it shouldn't.

New & top-hat-linered V8 blocks here.

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Fridge, the factory 4.2 is just a stroked version of the 3.9 and as such maybe has the bosses on the block for cross bolting but the main caps are unlikely to be suitable.

The 4.0 and 4.6 are brothers of the generation one step later than the 3.9/4.2.

I would tend to stick with the older generation 3.9/4.2 fitted with hotwire. As time went by the emissions regs were squeezed ever tighter encouraging ever leaner mixtures and thus ever higher running temperatures.

jw

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There seems to be some confusion here over the rover V8s.

There are 3 basic block designs-

A) early blocks from SD1 etc had rope seals and other oddities but are basically interchangeable with

B) what is often known as the stiff block. This did NOT have a cross bolt bottom end until very late in life and it is quite rare to find them as standard- although i have one in the shed which was a racing block and had a cross bolt kit welded on to it. These blocks are found in 3.5, 3.9 and 4.2 guise. Out of all of them the 3.5 are the most reliable - all the others seem to have a pretty good chance of liner slippage, porosity or cracking. These blocks came in 2 bore sizes with the 94mm bore producing the 3.9, and a stroker crank in the 94mm bore producing the 4.2. These blocks were used right up to 94/95 until type c:

C) these are the 4.0 and 4.6 blocks and are very different animals. For starters the pistons are of a different design- although the 94mm bore was still used. The line bore is significantly bigger and basically rules out interchangeability of cranks between type C and type a/b blocks. If you want to run type C then start with a short block. The front ends ARE interchangeable, however the later THOR engines which had no dizzy have a long nose crank- they can only be used with a later serpentine front end- similarily the full serpentine front end will NOT work with an early crank as the oil pump will no longer be driven (ie the long nose of the crank is needed to drive the serpentine oil pump). In the same way the later cams will not work with early front ends as there will be no oil pump drive. These blocks are all of a cross bolt variety although they don't all have the bolts installed and sometimes don't have main caps with bolt holes- there seems to be some debate that these later blocks don't suffer from porosity or cracking- frankly i think it's rubbish and wouldn't touch another rover v8 over 3.5 unless it had top hat liners- it's just not worth taking the risk IMO.

Casting methods didn't change between any of the different types (all sand cast with subsequent problems and issues- ie poor oil drainage in places), and all the bolt holes are in the same place, so with a bit of thought, a 4.6 could be made to look exactly like a very early 3.5 which i always thought might be interesting.

heads are a whole different kettle of fish and beyond my knowledge of whats what- there seems to be about 30 different designs and the same number of different combustion chamber sizes- different heads give different CR, but may have different valve sizes. I've never really understood it all to be honest!

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sorry i'd forgotten about that conversion- seems a little pointless to me- just MS and junk the carbs

Jim - It *is* MS'd I just don't want to do the Serp thing right now, only serp bit I'd want would the Thor manifold and that should bolt on without the front end. I need the remote oil filter kit and I don't think you can do that (as easily) with the serp setup.

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i've got a serp front end here- there are a couple of benefits- the oil pump seems like a much improved design, as does the water pump.

remote oil pump seems remarkably easy with serp front end- it already has two holes which come out of the side of the cover which are there for an oil cooler- ideally you would use these holes for the remote filter, and use a blanking plate on the old filter housing. Alternatively you use a remote oil take off where the filter would normally sit. Seems a huge amount easier than using a standard front end- it's also sealed of course so you don't need to fill holes up or use spacer plates.

I went through this thought process when thinking of building a 4.6 for me- decided that the serp front covers were far surperior to the standard ones in both performance and ease of setup.

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