SeaBass
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| posted on 28/8/04 at 05:22 PM |
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Rover V8 Head Gaskets
Just got hold of a running Rover V8 in a donor. Although it runs the engine is a bit unwell and I'm pretty convinced head gaskets are to blame.
Compression seems to be blowing into the coolant system. May be a common failure I don't know.
Anyone on here a Rover V8 expert/has changed head gaskets before. I have Haynes manual and Land Rover V8 e-manual. I'm going to follow the Land
Rover procedure prolly.
I presume it is advised you change both and not just the offending one. I haven't looked into getting gaskets but assume they come as a pair.
Any tips and tricks before I attempt it?? ie Is it essential to remove rocker gear first??
Cheers
JC
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JB
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| posted on 28/8/04 at 05:27 PM |
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Removing RV8 Heads
It is quite straight forward, as the cam is in the block.
The only problems you are likely to encounter is getting bolts out of the aluminium head and block. Be prepared for a few sheared studs or bolts.
John
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Stu16v
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| posted on 28/8/04 at 09:03 PM |
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This may be a silly question but....
How would you know which one was the offending head?
Dont just build it.....make it!
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Fatboy Dave
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| posted on 28/8/04 at 11:48 PM |
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Compression test normally. I ALWAYS change both gaskets. Seems silly not to when the engine has to come apart anyway, and there's only 25 bolts
between one HG and two (14 for the head, 8 exhaust, and thee rocker IIRC).
Only bolt trouble I have ever had in a running tally of 43 engines are exhaust manifold bolts. If you're a ham-fisted gimp that doesn't
know/care what a torque wrench is, you will strip one of them...
Just be careful is my advice. It's not hard, go for it!
Dave
Stop the planet, I want to get off
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Bob C
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| posted on 29/8/04 at 02:57 PM |
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old RV8 uses shim steel gaskets & these are only OK for so long - checkout the RPI website (www.v8engines.com?) You can get composite gaskets
which must seal better when everything ISN'T sparkling new - but they reduce compression. You can get the head skimmed by (i think) 8 thou to
make up the difference - probably not a bad idea if you've had coolant loss issues, rpi say you can't do this but it worked fine for me!
Summary - I'd say skim the heads & get composite gaskets. You're supposed to get new head bolts too because thy're stretchy ones
- they're probably OK for one rebuild but after a couple you're starting to ask for trouble.
Nice straightforward engine - shouldn't be a problem.
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craig1410
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| posted on 29/8/04 at 06:24 PM |
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Hi,
I'd stick with the tin gaskets if I was you but take heed of advice regarding how to torque up the head bolts. In particular, there are four
extra bolts along the outside edge of the head which are not present on later (post '96) engines. RPI recommends that you torque these up to a
lesser extent than originally specified to avoid head gasket problems. The figure they quote on
this page is 20-25lbf.ft
I would just get the head's surface machined the minimum amount to get a flat surface and use tin gaskets to keep compression at the standard
level.
You can get a top-end gasket set which will have everything you need. I also agree that you may as well rebuild both heads because all the stuff in
the middle (valley cover, inlet manifold) has to come off anyway and you can de-coke both heads, grind in the valves and have a good look at the level
of wear and tear of other parts at the same time. I must admit, I'd be tempted to renew the cam, timing gears and oil pump at the same time for
the same reasons.
The engine is straightforward to rebuild but be aware of the issues surrounding lifter/tappet pre-load. This is also described in RPI's website
here
I hope this helps,
Craig.
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SeaBass
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| posted on 29/8/04 at 07:33 PM |
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Thanks for the responses guys.
I'm going to start stripping the thing down on Wed afternoon prolly so I'll find out what's going on. Had a good look at the RPi
website but there's so much info on there I got a bit scared.
I'll report back on the progress.
Cheers
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DEAN C.
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| posted on 30/8/04 at 12:22 AM |
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Stripped and rebuilt about 20 of these engines,always crapped up in the rocker area with black death,but basically a very standard OHV design and easy
to work on except there is two of everything.
If you're pulling this engine out I'd check the crank as well ,because even though they run quiet I've not seen many that
wern't running on bronze on the bottom ends,these engines very rarely knock on the bottom end even when knackered,Hi pressure oil pump fitment
is a must as the old pumps put very low pressures out,SD1's were a bit better than standard though.
Once I've finished a project why do I start another?
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craig1410
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| posted on 30/8/04 at 12:41 AM |
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Dean,
I respect your opinion on the engine as you clearly have extensive experience of rebuilding it. However, from everything I have read most experts
agree that the Rover V8 does not need high pressure in the oil system and relies on oil volume instead. If you do want more oil pressure in an SD1
engine then you can fit a stronger pressure relief valve and get up to about 55psi but, again from what I have read, this is not necessary and just
absorbs power in the oil pump. I can't comment on the pre-1976 P5/6 engine but certainly the 1976 onwards SD1 and range rover engines have a
more than adequate oil pump provided it is in good condition.
Cheers,
Craig.
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SeaBass
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| posted on 12/9/04 at 08:18 PM |
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Well had a good go at changing the head gaskets on the V8. But someone has been in before and botched around with things. Three of the head bolts
seemed loose when disassembling. Alarm bells started ringing.
Very clean inside. No crap or 'black death'. I noticed before cleaning faces and changing gaskets that the 'loose' head bolt
threads had been helicoiled. When I came to start torqueing down headbolts the three that where helicoiled gave way under very little torque. What can
I do now?
Think the whole lump is gonna have to come out for a better inspection.
Oh well
Cheers
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Fatboy Dave
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| posted on 12/9/04 at 11:50 PM |
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Buggrit 
Are the stripped threads the four outer 'outrigger' bolts, or are they the main head bolts? Problem is, if they have failed with Helicoils
in them, then the block sounds pretty fecked. If you get it drilled/tapped/helicoiled over sized, it still leaves you needing an oddball headbolt.
Probably as easy/cheap to go get another block and transfer all the good bits over. Sorry to say, but it looks like someone has had a go, cocked it
up, and sold it on with HGF
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SeaBass
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| posted on 13/9/04 at 12:43 PM |
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Pretty much my thinking Dave. No such luck as them being the on the 'useless' rows. No these are three of the long bolts in the top row
that have failed. Two on one bank one on the other.
I'm looking into thick wall inserts where the outer 'holding' thread is a fair bit larger than the inner 'bolt'
thread.
Trouble is this means more machining. I've got three 3.5 blocks to play with but I was hoping to keep the 3.9.
Cheers
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NS Dev
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| posted on 13/9/04 at 04:57 PM |
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I know nowt about the Rover but I thought the only difference was pistons/liners? Can you reline one of your 3.5 blocks and keep your 3.9 pistons and
rods etc......just an idea might be total crap???
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craig1410
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| posted on 13/9/04 at 06:57 PM |
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Hi,
I might be being naive here but why is it so difficult to get the thread repaired? I find it incredible that a block might be scrapped due to a
stripped aluminium thread!
If you can get a thick wall insert fitted then why not convert the whole lot to using head studs and nuts rather than bolts. That way there will be
less wear and tear on the repaired threads as they will never be turning when under load. You might also be able to get oversize studs made up with a
larger thread at the block end and a standard shank and thread at the top. That way you could use an oversize but otherwise standard helicoil. Another
option might be to weld some material into the bolt hole and then drill and tap it out.
Hope this helps,
Craig.
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Fatboy Dave
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| posted on 13/9/04 at 11:28 PM |
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Craig, yes, oversize studs are a possibility. Done by a customer a while back on a trick 4.6 block, where replacement wasn't an option.
Wasn't cheap by any means. Meant a complete strip down to component level, throwing away all the bearings.
As the advert goes, reassuringly expensive.
There are always options to save the block, it just depends on how flush you are feeling. A used 3.9 short motor is ~400 at the moment. Cheaper(!) if
you go to eBay.
3.5 blocks can be relinered into a 3.9 quite easily (sorry fella, didn't realise it was a 3.9!), as the strokes are the same, it's just
the bores that were different.
Dave
Stop the planet, I want to get off
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craig1410
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| posted on 14/9/04 at 08:37 AM |
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Dave,
You said it needed a complete stripdown to fit the oversize studs but isn't it possible to do "in-situ" repairs using helicoils?
I've never used them myself so I don't know the process but I would have thought that all it needs is to drill the existing hole out
accurately to the size of the helicoil outer, tap to suit and then just screw it in.
Is the problem drilling the hole perpendicular to the block face and in the correct position? Surely not an impossible problem if you use a drilling
template made from some steel plate and use one of those attachments for your drill which keeps it perpendicular. Alternatively you could just use an
old cylinder head as a guide with a long drill bit.
Obviously you would have to control swarf but this could be accomplished with cling film or sticky plastic or something I'm sure.
Once again I may be being naive and I don't mean to sound argumentative but I simply don't see the problem here. I certainly
wouldn't scrap my own engine block unless I had at least tried the above first.
Cheers,
Craig.
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Fatboy Dave
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| posted on 14/9/04 at 07:46 PM |
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Craig,
Indeed, you could, but you'd have to have some serious skill and tools (or be VERY stupid IMO) to try it. And a machine shop is unlikely to
operate a mobile service to come to your door to do it 
Yes, a template/jig could be made to hold the drill bit in situ, but it would need to be made to a dgree of accuracy most people simply cannot work to
at home.
When you consider this engine stood the owner in the best part of 7k, I think he was just being cautious to not let a stray bit of swarf ruin an
expensive piece of machinery.
I just would not class it as being one of the things 'to have a go' at. Makes the potential difference between a borderline saveable
engine and a scrap block...
Dave
Stop the planet, I want to get off
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craig1410
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| posted on 14/9/04 at 07:58 PM |
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Dave,
Fair enough, I respect your point of view even though I don't share it. It'd be different if money was no object in which case a nice
shiny new cross-bolted block would be top of my shopping list to rebuild my aging SD1 engine but unfortunately money is in short supply in my house at
least. Also, what's the worst that if a repaired thread gives way - the head gasket will blow? IMHO it's worth a try but 'nuff said.
By the way, what did you mean by, "When you consider this engine stood the owner in the best part of 7k, I think he was just being cautious to
not let a stray bit of swarf ruin an expensive piece of machinery. "
I've read that sentence a few times and I've obviously missed something because I don't know what you mean, especially the first
bit.
Cheers,
Craig.
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SeaBass
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| posted on 14/9/04 at 08:09 PM |
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Thanks for the replies guys...
I'll update you soon (and hopefully stop the arguments!)
Cheers
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Fatboy Dave
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| posted on 18/9/04 at 09:16 PM |
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quote:
Originally posted by craig1410
By the way, what did you mean by, "When you consider this engine stood the owner in the best part of 7k, I think he was just being cautious to
not let a stray bit of swarf ruin an expensive piece of machinery. "
I've read that sentence a few times and I've obviously missed something because I don't know what you mean, especially the first
bit.
Referring to a customer of mine that I mentionned above. He managed to strip a head bolt thread when removing a head bolt. He was refitting an ARP
stud kit I sold him when the thread gave away. The engine in question was a twin turbo, based on a new 4.6 block, a stroker crank taking it to 5.4,
forged low compression pistons and rods, polished internally (inside the lifter vally, to aid oil drain back to the sump), fully deburred, the list
was endless. As I'm sure you can understand, a piece of swarf from a carelessly done repair with the engine in situ could have rendered this
fantastic piece of automotive pornography scrap, had it scored the crank, gotten to the oil pump, found its way to the cam etc..
If you feel you can do this sort of repair to a high enough accuracy, then fine, but I, speaking from bitter experiance (of the above engine) would
never contemplate such a task without the facilities of a good machine shop. It;s not something you hold a drill to and have a go at tapping out with
a £15 tap set.
Besides, I hoover up old Range Rover engines for £150 a time. The liners are replaceable, and never wear out. It's only this sort of damage that
potentially ends a blocks life. Witness my friend, with a Dax Rush. He has a 1969 engine, rope crank seal and all. Still going strong, with three
resleeves to it's name in its known history, and goodness knows what else to its name. Bits areslowly drying up, but they are by no means hens
teeth. A scrap block is not the crime it could be, had it been say, a Lotus Carlton engine...
Not trying to ruffle any feathers here, just want a good discussions on one of the best engines out there
Dave
Stop the planet, I want to get off
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craig1410
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| posted on 18/9/04 at 10:14 PM |
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Dave,
I think I see where the difference in attitude comes from.....I'm building a Locost!!
My engine cost me £200 as a fully running (and witnessed by me as such) SD1 engine with all the ancillaries, wiring, cooling system, clutch and
basically anything I wanted from the donor vehicle bar the gearbox.
I fully intend to rebuild the engine at some point and ideally I'll base it on a crossbolted range rover block but that will be a different
project and will only be started once my Locost is complete. Even then, I'll be looking for value for money with every purchase I make and
certainly won't be spending anything like £7000 on the rebuild. I'm hoping that £1200 will go a long way and even include a Weber 500
carb!
I agree that a replacement block can be relatively easily found and at a reasonable cost but only a fool would just bolt all the old bits onto the new
block and hope it will be hunky-dory. As soon as you replace the block you are committed to a full rebuild with bores getting honed, new piston rings
(maybe pistons too), new camshaft and followers, new rocker gear probably, new bearings all round, crank regrind, heads resurfaced, valve guides
replaced, valve seats cut, maybe new valves, new oil pump probably - the list goes on!
If I stripped a thread right now then I would certainly attempt an in-situ repair and I would be confident in my ability to keep swarf out of the
engine. Getting the accuracy with the drilling would be the greatest challenge but I'd have a go. The fact is that I simply wouldn't be
able to afford to rebuild the engine while still completing the car itself so I'd have to do my best to keep it together with a temporary repair
in the meantime. I know that what you are saying is "right" but perhaps not right in all circumstances and for all people.
All the best,
Craig.
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Fatboy Dave
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| posted on 18/9/04 at 11:21 PM |
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That's very true Craig, not *everyone* (myself included!) can afford to tear an engine down to the last nut and bolt to replace a block because
of a catastrophe like that.
I agree, a rebuild can get expensive, but it depends on the circumstances surrounding the engine. I *have* got away with using an old crank an
bearings in an old block, but it involved a fair bit of time with the ol' micrometer to match up a set of main caps to make sure the engine
wouldn't rattle like a bag of spanners. I was too poor to afford new shells, and even the gasket set was on tick at the time It can be done, and
a stripdown doesn't always mean new bearings and bits everywhere, but it *should* in an ideal situation.
In the case of a stripped head stud (to bring this mildly back to topic!!), I can see me removing a head, and making some form of drilling jig that
picked up on a couple of headbolt holes to allow one to drill perpendicular to the block. Then, a sh*tload of loctite, and stick it up on eBay...
<ahem>
Ahhh, a nice adult discussion without a flame war  refreshing
[Edited on 18/9/04 by Fatboy Dave]
Dave
Stop the planet, I want to get off
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craig1410
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| posted on 19/9/04 at 12:14 PM |
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Flame wars are only for those who can't put forward a decent argument in my opinion...
Also, I think we both appreciate each others points of view which always helps.
My list of rebuild parts in my last posting are taking account of my own SD1 90000 mile engine which will almost certainly need a variety of valve
gear related parts (camshaft, followers, rocker shafts and rockers, valve guides, timing gears & chain etc etc) I actually hope to go a bit
farther and actually blueprint the engine (properly!) which will increase the cost a bit obviously. It would seem daft to use an old SD1 block for
this exercise to a crossbolted block will probably be used instead with Vitesse 9.75:1 pistons and heads.
Come to think of it SeaBass, if you would care to wait a year or so, I might have a nice intact SD1 engine block for you!!
Cheers,
Craig.
ps. Nice debating with you Dave, we must do it again some time!
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