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3.5,3.9 & 4.2 heads


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You sound sooo convincing too. My Disco had a 10 bolt block. There were no extra holes. 10 bolt heads. Small main bearing block with exactly the same crank as an early 3.9. Block was not drilled for cross bolts but was drilled for a cam retaining plate. But I don't know anything, must have had my eyes closed while I rebuilt it. Maybe you should do a google search on the 3.9 "interim" motor.

my 1993 4.2 is like the above but 14 bolts, with a dizzy driven oil pump. i have machined my cam to take the cam retainer.

my 1995 4.6 is 10 bolt heads...but the block has 14 holes available.

there are a few odd varients around this era.

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You sound sooo convincing too. My Disco had a 10 bolt block. There were no extra holes. 10 bolt heads. Small main bearing block with exactly the same crank as an early 3.9. Block was not drilled for cross bolts but was drilled for a cam retaining plate. But I don't know anything, must have had my eyes closed while I rebuilt it. Maybe you should do a google search on the 3.9 "interim" motor.

You seemed to have missed this sentence in my last post

Also there are a number of strange build engines from around that era which used parts common to both suffix A & Suffix B……………

TBH. judging by your performance on the lambda thread and your performance here I will be surprised if you are around for very much longer ;) ......... its been nice knowing you...... :D

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You seemed to have missed this sentence in my last post

TBH. judging by your performance on the lambda thread and your performance here I will be surprised if you are around for very much longer ;) ......... its been nice knowing you...... :D

The only reason I won't be around is having to deal with people like yourself. I thought this forum appeared to be a friendly lot, that is why I joined. But did not even receive a basic welcome when I joined. It also appears that there are a couple of Alpha males here that do not like anyone questioning what they post.

You fail to do any basic research before stating things as fact. Even your own posts contradict themselves as to the thickness of head gaskets. If you did the simplest search you would know that they made the 3.9 with the short nose crank and 10 bolt heads up to 1998. The 4.0 had a longer crank nose and cannot be fitted to a distributor timing cover without a 30mm spacer. The 4.0 went to a completely different crank, conrods, pistons, and cross bolted main bearings. Again even if you did a basic search on parts for a discovery, you will notice that these parts did not change on the Disco in 1994. Some parts did change in 1996 in NAS vehicles only when they went to the GEMs motor. Yes, they started making the 4.6 for the Rangie with the P38 and that is why the block mold changed on the 3.9's. That is, you will see a place for the cross bolts, but there are no holes or bolts. That is why they refer to these motors as the 3.9 interim motor as they filled in the gap from the mold change for the 4.6 and the introduction of the 4.0. But internals such as crank, conrods, piston stayed the same as the 3.9.

I have finished debating this. Anybody on this forum can do a basic internet search themselves and work out what is right and wrong.

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It would help if you didn’t have selective reading & understanding……… ;)

Like I said…. It ceased production and the interim motors were made from old stock parts as it was very small volume……….I think most on here know about long nosed cranks and the dizzy t/case. :rolleyes:

You just can't help yourself. Yes they produced another 4 years of discoveries with scrap parts they had sitting around. And of course they only sold in very small volumes. 392,443 first-generation Discoverys were built in nine years, for an average of 43,604 per year.

This debate is now just ridiculous.

A couple of quick searches on the net showed up these two specs from official vehicle sites (not forums). Except for NAS vehicles the 4.0 was not introduced in Discoveries until the Series II.

Why haven't you explained why my 3.9 only had 10 head bolt holes in the block if it was just rover using up old 3.9 motors.

Land Rover Discovery

1989: Land Rover Discovery is unveiled at the Frankfurt Motor Show, Tuesday 12 September.

Coil sprung, full-time 4WD, 5-speed manual LT77 gearbox, LT230T transfer case, locking centre diff, 100 inch wheelbase.

Initially 3.5 V8 and 2.5 (4cyl) Tdi, 2 door.

1993: 1994cc MPi petrol 4cyl option.

1994: 3.9 V8i and 2.5 (4cyl) Tdi, 2 door and 4 door, 5-speed manual (R380) and 4-speed auto, driver's air-bag and optional passenger air-bag.

1998 Sept: Updated Discovery 2, Code-name Tempest, finally launched (5 September) - 4.0 V8i or 5-cylinder Td5 diesel longer and wider than old car.

2004: Discovery 3 (LR3 in some markets) Launched.

Jaguar 4.4 litre V8 petrol, 2.7-litre V6 turbodiesel, 4.0-litre V6 petrol. Full-time four-wheel drive.

Both petrol derivatives are matched to a six-speed automatic ‘intelligent shift’ transmission, also available with the diesel though this has a six-speed manual as standard. 2009 September: Discovery 4 launched on UK roads.

Models Covered: Series I Discovery - 1989-1994 (2.0 Stn Wagon 3 and 5dr [MPI, MPI S]/ 3.5 8cy Stn Wagon 3 and 5dr [V8, V8i, V8i S] / 3.9 8CY Stn Wagon 3 and 5dr [V8i, V8i S] / 2.5 TD Stn Wagon 3and5dr [Tdi, Tdi S]

Facelift Series I Discovery - 1994-1998 (2.0 Stn Wagon 3 and 5dr [MPi, MPi S]/ 3.9 8cy Stn Wagon 3and5dr [V8i, V8i S, V8i XS, V8i ES] / 2.5 TD Stn Wagon 3and5dr [Tdi, Tdi S, Tdi XS, Tdi ES]

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There's 2 very different tones in this thread, think one needs to calm down a just a tad :)

'Arguing on the internet is like running in the special Olympics..........'

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You just can't help yourself. Yes they produced another 4 years of discoveries with scrap parts they had sitting around. And of course they only sold in very small volumes. 392,443 first-generation Discoverys were built in nine years, for an average of 43,604 per year.

This debate is now just ridiculous.

Keep on taking the tablets ! :lol:

Why haven't you explained why my 3.9 only had 10 head bolt holes in the block if it was just rover using up old 3.9 motors.

maybe I wasnt in the factory the day yours was built :rolleyes: .......... you obviously have no idea how a production line works and small volume builds ............

Historically I think you will find that the 4.0L was introduced into he RR in very early 95 and IIRC the whole V8 assembly line at that time was turned over to the production of the 4L / 4.6L suffix B engines. As has already been said, there are some quite strange engine builds from that period.

Yes they produced another 4 years of discoveries with scrap parts they had sitting around.

I never said scrap parts ……… these parts would have been laid aside for small volume production. I cant find the figures, but I would suspect that the V8 disco probably only accounted for maybe 1% of the total production (less than 3 – 4K per year based on your figures). Certainly, in the UK you can pick up a V8 disco very cheaply indeed, but there are not too many around from that era. When the 300Tdi was introduced to that model in 94 it became a best seller. My suspicion is that they kept the small production of the 3.9 in the disco to differentiate between model types, which is something that LR have always done …….. i.e a low spec RR had the 4.0L as against the disco having a 3.9…………

With all that has been said and done, you have managed very well to divert attention away from the misinformation and lack of understanding that you posted regarding CR's and the effect of head gaskets vs chamber volumes..........even now you fail to understand that the V8 disco was a small volume model in comparison the 300Tdi model..........maybe the queens English is not your first language............ :rolleyes:

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Keep on taking the tablets ! :lol:

maybe I wasnt in the factory the day yours was built :rolleyes: .......... you obviously have no idea how a production line works and small volume builds ............

Historically I think you will find that the 4.0L was introduced into he RR in very early 95 and IIRC the whole V8 assembly line at that time was turned over to the production of the 4L / 4.6L suffix B engines. As has already been said, there are some quite strange engine builds from that period.

I never said scrap parts ……… these parts would have been laid aside for small volume production. I cant find the figures, but I would suspect that the V8 disco probably only accounted for maybe 1% of the total production (less than 3 – 4K per year based on your figures). Certainly, in the UK you can pick up a V8 disco very cheaply indeed, but there are not too many around from that era. When the 300Tdi was introduced to that model in 94 it became a best seller. My suspicion is that they kept the small production of the 3.9 in the disco to differentiate between model types, which is something that LR have always done …….. i.e a low spec RR had the 4.0L as against the disco having a 3.9…………

With all that has been said and done, you have managed very well to divert attention away from the misinformation and lack of understanding that you posted regarding CR's and the effect of head gaskets vs chamber volumes..........even now you fail to understand that the V8 disco was a small volume model in comparison the 300Tdi model..........maybe the queens English is not your first language............ :rolleyes:

You have not provided one piece of proof that a 4.0 motor was ever put into a series 1 discovery outside NAS vehicles. Again you just pluck figures out of the air with you stating that only 1% of the Discoveries were V8. You forget that all Discoveries sold in the US prior to the engine change in 96 were V8's.

You do not want to even acknowledge that the 3.9 was only first introduced into the Discoveries until 94, the year you claim they ceased producing it.

It would appear that you are the one attempting to divert things. You did your calculations on the head gasket only being 20 thou thicker. Then you posted information that claims it was 30 thou thicker. But you choose to ignore information contained in your own posts. In your early posts you stated that you could machine down a 14 bolt head by 40 thou to use composite gaskets. This is exactly how much Rover did machine the heads to reduce the capacity by 8CC. So why did the machine the heads 40 thou when the gasket thickness only change by 30 thou. Simple the bowl in the head is not a full circle or the same diameter as the bore.

You have admitted that the Series 1 discoveries had a distributor and therefore did not have the long nose crank that was fitted to the 4.0

So you have not disputed that the head capacity changed by 8CC. You have posted information that shows the composite gasket is 30 thou thicker. You have stated that the head was machine by 40 thou. But you want to continue to argue that the gasket only makes a 3.5CC change. If it was a 8CC change, your own calculations would show a change in compression ratio of 1.4.

There is simply no winning with you. Your own information proves you are wrong, but you keep on posting information that shows you know very little about what changed in Rover V8s and when.

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You have not provided one piece of proof that a 4.0 motor was ever put into a series 1 discovery outside NAS vehicles. Again you just pluck figures out of the air with you stating that only 1% of the Discoveries were V8. You forget that all Discoveries sold in the US prior to the engine change in 96 were V8's.

You have not posted any confirmed figures that dispute my estimate............

You do not want to even acknowledge that the 3.9 was only first introduced into the Discoveries until 94, the year you claim they ceased producing it.

That is not quite what I posted. The 3.9 as a suffix A engine ceased production line manufacture as the production line was turned over to the Suffix B engine in late 94. As with every manufacturer, small volume builds by pipline forcasting would have been be catered for. Having said that LR are absolute masters of the parts bin.

It would appear that you are the one attempting to divert things. You did your calculations on the head gasket only being 20 thou thicker. Then you posted information that claims it was 30 thou thicker. But you choose to ignore information contained in your own posts. In your early posts you stated that you could machine down a 14 bolt head by 40 thou to use composite gaskets. This is exactly how much Rover did machine the heads to reduce the capacity by 8CC. So why did the machine the heads 40 thou when the gasket thickness only change by 30 thou. Simple the bowl in the head is not a full circle or the same diameter as the bore.

Off course its not a full circle :rolleyes:. The rover V8 combustion chamber is an open wedge (dished piston). It is this shape that dictates the speed of the flame front and thus the maximum design ignition advance.

Nowhere has 30 thou been quoted. it would seem not only is your grasp of understanding of the written word rather poor, but the ability to undertake simple mathematic calculations also eludes you. My figures are only from one manufacturer and if you care to undertake a little research the figure will be 18 thou best case and 28 thou worst case.

So you have not disputed that the head capacity changed by 8CC. You have posted information that shows the composite gasket is 30 thou thicker. You have stated that the head was machine by 40 thou. But you want to continue to argue that the gasket only makes a 3.5CC change. If it was a 8CC change, your own calculations would show a change in compression ratio of 1.4.

This is well documented. The chamber volume went from 36cc to 28c, but this was not purely a result of a gasket change. The piston bowl and the piston cylinder volumes also changed. Interestingly, the original Buick head chamber was still of an open wedge design but 57cc volume and an almost flat top piston.

There is simply no winning with you.

:lol::rolleyes::lol: hook line and sinker comes to mind..............

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You have not posted any confirmed figures that dispute my estimate............

No need to. Typical of your sort of argument is to put up figures with no proof but then expect others to prove you wrong.

But this might give you an estimate for USA alone (remember they were all V8s)

Land Rover Models:

Land Rover Discovery I Years:1994-1997

Range Rover Classic Years:1993-1995

Number Potentially Involved: 45,267

Dates of Manufacture: December 1993–November 1996

Defect: On certain sport utility vehicles, the plastic fuel tanks can develop stress cracks. Fuel tank cracks can result in fuel leakage from the underside of the vehicle when filling the tank, particularly if overfilling is attempted. Fuel leakage in the presence of an ignition source could result in a fire.

Remedy: Dealers will replace the fuel tank. The manufacturer has reported that owner notification is expected to begin during October 2004. Owners may contact Land Rover at 1-866-352-4827.

That is not quite what I posted. The 3.9 as a suffix A engine ceased production line manufacture as the production line was turned over to the Suffix B engine in late 94. As with every manufacturer, small volume builds by pipline forcasting would have been be catered for. Having said that LR are absolute masters of the parts bin.

200,000 motors is obviously a small run in your books. I am not debating that there was no suffix A motors built after 94, what I am stating is that the Suffix B 3.9 motors had the same pistons, crank and conrods as the suffix A. This is supported by the Rave CD for the 3.9/4.2 motors that mentions no differences in these areas between the suffix A and B 3.9 V8's but lists these differences.

This is what the Rave CD states about 3.9 motors (not 4.0 motors)

Engine numbers without suffix B

The full flow lubrication system uses an external gear pump which is driven by the distributor drive shaft. The oil pump gears are housed in the timing cover and the oil pressure relief valve and warning light switch are fitted to the oil pump cover.

Engine numbers with suffix B

The full flow lubrication system uses a gear type oil pump driven from the crankshaft. The assembly is integral with the timing cover which also carries the full flow oil filter, oil pressure switch and pressure relief valve.

It also shows the head bolt tightening sequence for 3.9 suffix B engines with 10 head bolts and other 3.9's with 14 bolts

It also has this warning:

CAUTION: Engines without suffix B have a steel gasket whilst engines with suffix B have a composite gasket. The two types of gasket are not interchangeable and it is essential to ensure that the correct type of gasket is fitted.

Nowhere has 30 thou been quoted. it would seem not only is your grasp of understanding of the written word rather poor, but the ability to undertake simple mathematic calculations also eludes you. My figures are only from one manufacturer and if you care to undertake a little research the figure will be 18 thou best case and 28 thou worst case.

You have posted a figure of 28 thou from a gasket manufacturer, sorry for my rounding. Feel free to post a reliable source that states anything less than that. Heres one from me that states 30 thou http://www.mez.co.uk/TuningTheRoverV8-pt11.html

And here is one that gives the impact of the head gasket at 7CC (twice your calculation) http://www.v8church.co.uk/engine_parts/v8_head_gaskets/

This is well documented. The chamber volume went from 36cc to 28c, but this was not purely a result of a gasket change. The piston bowl and the piston cylinder volumes also changed.

Well these businesses in the UK have obviously got it wrong too as they only list one HC and one LC piston for the 3.9. No mention of different years or suffix A or B

http://www.v8tuner.co.uk/category.php?id=27

http://www.rimmerbros.co.uk/Item--i-GRID008882

http://www.realsteel.co.uk/section1.pdf

This time I am done debating this. Everyone else is wrong (including Land Rover) and you are the only one that knows the correct story, there is no getting through to people like yourself.

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This is fantastic :D ......please don't tell me who dies in the end.

I've stopped watching Eastenders, and started reading this.....It's BRILL!! :lol:

Keep it up lads.

By the way mines a 3.5 Efi out of a RRC.....Can you tell me what colour it was painted in the factory??? :lol:

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Will you use tin or composite gaskets :P

I've got a Frosties packet here I could cut some holes in, not sure which is better for compression ratio though - Frosties or Coco Pops? :unsure:

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What if I pull the 3.9 heads off my 4.6 and replace them with a pair of 200TDi heads? :ph34r:

I am glad that you can make fun of this discussion, but then again you have not been in a position where it has made a difference. But myself and others have and believe me, it is an important matter.

We did not receive HC 4.6's here. A friend of mine spent a lot of money changing the pistons, etc in a LC 4.6 block to HC. He then went to a Land Rover expert to get HC heads. No knowing the difference, he was sold LC heads. He assembled the motor with Composite gaskets and effectively now has a LC 4.6 with about 15% less power than a HC unit. He is also running it on straight LPG and therefore the drop in compression ratios has a significant effect.

I bought a 4.6 for my old Rangie. It was a brand new motor from LR when fitted to the vehicle I extracted it from. It was stamped as a HC block. It ended up that the person fitting the motor swapped out the HC pistons for LC pistons. It also had 14 bolt heads and composite gaskets. This meant that the compression ratio was down in the high 6's and the thing ran like a dog. Even though my 98 Disco had a 3.9 interim motor with 10 bolt heads, I fitted a 4.6 LC block to it. As stated above, composite gaskets on a LC block can have a hell of an effect if you don't have the right heads. After a lot of checking I could determine that all 10 bolt heads were correct for composite gaskets. I have now just finished fitting a new 4.6 to the 93 Rangie. Again it is a LC block. But as it was a earlier 14 bolt 3.9 I had to source new heads at a lot higher price than using the heads that I had.

So from personal experience, the use of the wrong gasket on the wrong heads has a very real difference on power and the performance of the engine. This is why others should benefit from mine and others mistakes and not do the wrong thing. It does not help when other members get on a thread and spout incorrect information. So make fun of the debate, but at least you will know in the future if what to do if the situation arrives.

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I've got a Frosties packet here I could cut some holes in, not sure which is better for compression ratio though - Frosties or Coco Pops? :unsure:

Frosties you idiot, their Grrrrrrrrrrrrrrrrrrrreaaat

Coco pops have a chocolate coating which is as much use as a teapot

Nige

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I know its a rare cereal now in the UK, but would it be worth the expense of fitting a Lucky Charms gasket if i could track some down? I have heard of people in the US getting good results with these... :ph34r:

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I've been following this thread since it started. Very informative at first but now seems to have developed into a personal duel, which is a pity as that's surely not making proper use of a forum. At the considerable risk of being refered to as a 'boring old fart' I'd suggest that perhaps owners should accept the design capability of the vehicles they buy but if driver demands exceed that of the manufacturer's intentions it's probably better (& safer) to look for something different. My own standard 3.5efi auto is (like me) a plodder compared to later products, but should the day come when I want more performance I'll buy a car designed & built for that express (no pun intended) purpose. Perhaps folks with horns locked over a particular subject should make use of the site's PM facility.

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Well these businesses in the UK have obviously got it wrong too as they only list one HC and one LC piston for the 3.9. No mention of different years or suffix A or B

http://www.v8tuner.co.uk/category.php?id=27

http://www.rimmerbros.co.uk/Item--i-GRID008882

http://www.realsteel.co.uk/section1.pdf

You have quoted 3rd party suppliers. Whilst we all use these folk for some of our parts they do not carry a complete stock, however, I found a number of options on all of the sites…….. I guess you were just being selective again….. :rolleyes: Intersetingly I spend quite a lot of money with one of those suppliers............

OEM there are currently six (6) 3948cc pistons available, however, when the assembly line was in place there we eight options

3948cc Piston HC RTC2295S (also available in +20 – RTC229520) which went to STC909 and is now 8510068

3948cc Piston LC RTC2186S (also available in +20 – RTC218620) which is now 8510109

3948cc Piston HC ERR5553 (Standard) ERR5553A (A Grade) ERR5553B (B Grade)

3948cc Piston LC ERR5555

I bought a 4.6 for my old Rangie. It was a brand new motor from LR when fitted to the vehicle I extracted it from. It was stamped as a HC block. It ended up that the person fitting the motor swapped out the HC pistons for LC pistons. It also had 14 bolt heads and composite gaskets. This meant that the compression ratio was down in the high 6's and the thing ran like a dog. Even though my 98 Disco had a 3.9 interim motor with 10 bolt heads, I fitted a 4.6 LC block to it. As stated above, composite gaskets on a LC block can have a hell of an effect if you don't have the right heads. After a lot of checking I could determine that all 10 bolt heads were correct for composite gaskets. I have now just finished fitting a new 4.6 to the 93 Rangie. Again it is a LC block. But as it was a earlier 14 bolt 3.9 I had to source new heads at a lot higher price than using the heads that I had.

In the above I have highlighted (bold text) statements that are incorrect, although I think you know what you mean, its just stated wrongly……..

There is only one block Suffix B block (this would apply to late 4L & all 4.6L) LCF104860 and the CR is governed by the Piston of which there are currently 4 options.

4554 Piston HC ERR5554 (standard) ERR5554A (A Grade) ERR5554B (B Grade)

4554 Piston LC ERR5556

So you have not disputed that the head capacity changed by 8CC.

I think we have done this to death, however, here we go again.

The 28cc chambered head was part of the phase II design package and takes into account not only the thickness of the gasket (which is slightly variable) but also the fact that the bowl in piston ERR553 (AB) is of more capacity than that of piston 810068.

TBH when you rebuilt your engine you would have been better off using Ford V6 forged pistons………. Or KB pistons http://www.kb-silvolite.com/index.html

This time I am done debating this.

Yes, you keep repeating this but still come back for more punishment ........... :ph34r:

This has been most enjoyable.............

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At the risk of ruining my reputation for talking b*ll*cks, some interesting tech just happened there...

Ian, care to expand on the difference between "standard", "A grade" and "B grade" pistons, and the use of Ford (or other) pistons in a Rover lump? Sounds like it could be a useful thing to know both from an engine building perspective and an emergency spares perspective. I have to admit I'd never really considered the interchangeability of things like pistons.

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John,

The way I understand it is, A , B and then standard and it comes down to the machining tolerance of the final product …….. with A at the top of the tree.

Ford 5.0L and 4.6L (oversize bore) modular engine pistons are 94mm bore and can be used with various combos of conrods to construct a fairly bullet proof piston arrangement………

Look up Ford modular engines……………….also IIRC the 2.6L V6 cologne pistons were used in the early days but that might be more 3.5L size………..

Most of these options are not direct drop in replacements and a certain amount of machining will be required ......but if you are re-machining the block anyway, then it suddenly becomes attractive..... ;)

However, the favourites were always Cosworth pistons………..

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