HG, should I skim the head?

Hi All,

I am after a little bit of advice, I am currently removing the head of my freelander 1.8 as the head gasket was showing sines of failure and I wonder what your thoughts are on skimming/reworking the head.

I have had a lot of contradictory advice on this. Some say to send the head off, have it skimmed, pressure tested and the valves re-ground.

Others have said, as the alloy head way harden it was not suitable for skimming as a softer metal would be exposed and as long as its flat re-fit it.

Lastly I have also heard worry stories of the head being cracked/fractured and didn't know if this is also a common problem on the K-Series?

My inclination is just change the gasket but I would prefer not to do the job twice, what are your thoughts?

Kind Regards,
Angus

Angus-32 said:

I am after a little bit of advice, I am currently removing the head of my freelander 1.8 as the head gasket was showing sines of failure and I wonder what your thoughts are on skimming/reworking the head.

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The head will only need work, if the fire ring lands (area where the gasket fire rings press) are showing signs of recession.

Angus-32 said:

I have had a lot of contradictory advice on this. Some say to send the head off, have it skimmed, pressure tested and the valves re-ground

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You can do that, but unless there's a problem with valve seats or head face damage, there's little point.

Angus-32 said:

Others have said, as the alloy head way harden it was not suitable for skimming as a softer metal would be exposed and as long as its flat re-fit it.

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The head is made of heat treated alloy (I forgot the grade off hand), but it's a full thickness heat treatment, meaning you can skim the surface and not affect the harness. However if the head has been overheated above about 125°C, then some of the heat treatment properties are lost, and the head will be soft and fail quickly.

Angus-32 said:

Lastly I have also heard worry stories of the head being cracked/fractured and didn't know if this is also a common problem on the K-Series?

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Maybe on a seriously abused head, but the K Series head doesn't generally suffer those issues.

Angus-32 said:

My inclination is just change the gasket but I would prefer not to do the job twice, what are your thoughts?

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You'll not know the condition of the head, until you get it off for inspection, but any doubts on its condition or harness should prompt you to get a replacement.

I've seen lots of new heads on ebay lately, for less than the price of reconditioned heads. So if the head viability is in any doubt, I'd get a new one.

Thank you for your advice as always Nodge,

I am halfway thought the removal and should have the head off by tomorrow if I can get some Torqes bits to do the head bolts.

I have seen a fully built up head but its not supplied with the cams, is it hard to swap over the cams from the old engine?

Angus-32 said:

I can get some Torqes bits to do the head bolts.

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You can use a single hex socket to drive them if you're stuck.

Make sure you don't rotate the engine with the head off.

Angus-32 said:

I have seen a fully built up head but its not supplied with the cams, is it hard to swap over the cams from the old engine?

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Yes. Remove from the old head and fit into the new head, using the correct sealer (Loctite 574 is my go to flange sealer) and new cam oil seals.

Good luck with it, I've only done a couple in my time so will always defer to the experts.
I used a good quality rule to confirm the head was still flat and not warped. If you only recently bought the car it won't be possible to confirm whether it was overheated or not but if the head is flat and no signs of softening I wouldn't replace it.
Make sure you check the liners are Ok
Make sure you replace timing belt, tensioner and water pump.
Take photos of the cam pulleys at TDC before removing the timing belt so you know you have it right afterwards. Refitting the timing belt is not that hard but it is very common for folk to get one of the cam pulleys one tooth out so they look like they are half a tooth out when the crank is at it's marker.