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Discussion Starter · #1 ·
Hi im wanting to get my head skimmed, but not sure were to get it done, im based in chesterfield, derbyshire. Anyone know anyone decent who could do it, or they have used in my area?
 

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Has it been warpped ?
Resurface every time it's removed from the engine, unless it is still within the factory tolerance for the mating surface, forget the units but its so many x per mm.

Most people take a ruler and say its level, but then most have failures straight after :)
 

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Resurface every time it's removed from the engine, unless it is still within the factory tolerance for the mating surface, forget the units but its so many x per mm.

Most people take a ruler and say its level, but then most have failures straight after :)
If it does not need a skim then it's not recomended due to the head losing it's heat properties and in turn making the head softer.
 

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What heat properties? Is it a special head or just cast ally?
Not got much of a clue of the desing tbh hob...I'm just saying what i have read when i looked into it...:) Can't find where i read about the heat properties but i should imagine it's on the same lines as the head becoming porus as mentioned below :)


Just bear this in mind when the common and uneducated comments come thick and fast that because your head gasket has gone you must have the head skimmed. NOT TRUE. Fact - if you have the head off the car for any reason then use a straight edge and measure for any face distortion and if present measure it and see if it is inside or outside tolerance and act appropriately.

The heads from the factory are given a "special coating" because they are so poorly made once they have been machined. He said, the sharper the milling tool to skim, the worse the surfcae was, this caused the head to push the material along (not visable to the eye) causing it to be porus. In other words, the heads are of poor casting quality.
 

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Discussion Starter · #11 ·
Cheers for the advice, i ve got two heads, one that needs a skim and the other that im not sure, so i will get a clock on it and see if there is any warping.
 

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use a straight edge and measure for any face distortion and if present measure it and see if it is inside or outside tolerance and act appropriately.

- A straight edge will not give accuracy down to 0.05 mm

The heads from the factory are given a "special coating" because they are so poorly made once they have been machined.

- No idea what that sentence means, even if the metal is slightly porous the Head gasket itself is what makes the seal.
 

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from what i have been told, the bottom 0.2 mm of the head of the K is sort of pressure treated to make it stronger than the rest of the head, skim past that, and the head is pretty much jelly.
 

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from what i have been told, the bottom 0.2 mm of the head of the K is sort of pressure treated to make it stronger than the rest of the head, skim past that, and the head is pretty much jelly.

There is a limit to the skimmage but afaik there is no dependance on the composition/casting or finish to the head.
 

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the following is a post by a member of the wizards of nos forum, she builds race engines for a living, so i assume she knows what shes talking about

Sorry to hear of your problems Kyle.

Head gasket weakness is, of course, a well documented problem on the K Series motor, mainly on the 1800cc variants (albeit over-documented IMHO). There are a number of theories as to why - head shuffle on the early plastic dowels, thermal cycling because of the thermostat (the TF gets a PRT from late '03 onwards). Commonly the thermal cycling leads to the inlet side of the head getting hotter than the exhaust side (strangely enough) which results in inlet gasket failure with concommitant water loss. Unless you see it go (cloud of steam) it is a very difficult water leak to trace. I'll bet a pound to a pinch of salt this is what happened on your motor not warpage of the head.

I contend that in the majority of cases the cause of head gasket failure (HGF) is water loss (there is very little volume to the water jacket so any coolant loss rapidly causes localised 'hot spotting' leading very quickly to HGF), however the OEM gasket (which has gone through 3 re-designs) is of a poor basic design for use in the 'stretched' K's. You have to remember the engine was originally designed as an 1100 cc unit for the Rover Metro. At the time it didn't make economic sense to fit a multi shim gasket since these were prohibitively expensive to fit to a 'shopping trolley'. There have also been issues with poor build / quality control at the factory although this seems to affect earlier vehicles (eg there were a batch of poor head castings done around '02 and a number of engines were built with the wrong liner 'stand proud' height).

Fortunately it sounds like you have got the new Land Rover multi shim gasket or possibly the Payen 'Head Saver' shim gasket. You need to check, however, whether they fitted the replacement oil rail (if it's the LR gasket) and whether they used new 'stretch bolts' to clamp the head. Only a muppet re-uses the bolts after HGF, but unfortunately I've seen it done on far too many occasions.

With regards to skimming the head, Trev is right, a lot of garages automatically do this because they don't know enough about the K Series engine (and they want to charge you £££), and in fact, skimming can lead to further problems with HGF, albeit with a multi shim gasket this is less likely. This is because of the nature of the way the engine is constructed. In many respects the K uses Formula 1 techniques to get its great power:weight ratio (best in its class); to do this a very lightweight alloy was used (the whole engine is only 85Kg, cf my all alloy 1000cc Climax engine at 65 Ks!) and to ensure the alloy is strong enough it is case hardened using a quenching technique. The upshot of this is that the case hardening is only 20 thousands of an inch thick on the head face - skim the head and you can rapidly go through this, overheat the head and you destroy the hardening.

So, skimming a K Series is generally a bad idea, despite what all the 'armchair experts' on any number of forums say (experts who wouldn't know good engine building technique if it bit them in the rear end).

If you have indentations around the fire rings it indicates the case hardening has been destroyed through overheating and the head is scrap. If the head is warped you can get away with a minor skim (and a multi shim gasket), but a far better technique is to straighten the head under heat/pressure and then re-quench it. Unfortunately this requires a specialist workshop.

Having said that, unless the head has been 'cooked', it is very unlikely to have warped in the first case (and a steel rule and micrometer check is easily enough done). More critical is the liner 'stand proud', especially with the multi shim gasket, unfortunately most non K Series specialists know bu**er all about this which compounds the problem of skimming. This is why so many second HGF's occur.


Depending on how much was skimmed you may well not have a problem with compression ratio as the multi shim gasket causes an increase in chamber volume (on a stock engine).
 

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You have to remember the engine was originally designed as an 1100 cc unit for the Rover Metro. At the time it didn't make economic sense to fit a multi shim gasket since these were prohibitively expensive to fit to a 'shopping trolley'.

In many respects the K uses Formula 1 techniques to get its great power:weight ratio (best in its class); to do this a very lightweight alloy was used (the whole engine is only 85Kg, cf my all alloy 1000cc Climax engine at 65 Ks!) and to ensure the alloy is strong enough it is case hardened using a quenching technique. The upshot of this is that the case hardening is only 20 thousands of an inch thick on the head face - skim the head and you can rapidly go through this, overheat the head and you destroy the hardening.

Wow didn't know or expect the K-series to have a case hardened head, does anyone know what the k-series was designed for? As they seemed to have a highly complicated engine for a budget car and on the weight side of things, the cars they put them in are not exactly light, especially the ZR.
 

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well, i dont know what the original design brief was, but you cant deny that for all its faults, its an awesome engine as far as lightweight and decent power is concerned, look at all the lotus', caterhams etc that use it for race application, albeit rebuild a tad stronger, lol.
 

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Wow didn't know or expect the K-series to have a case hardened head, does anyone know what the k-series was designed for? As they seemed to have a highly complicated engine for a budget car and on the weight side of things, the cars they put them in are not exactly light, especially the ZR.
I always though the Caterham and the Elise/Exige were pretty light cars?
 
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