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My GEMS 4.0 has started blowing to atmosphere from one of the driver's side cylinders. It's not quite as loud as Miah's was (yet!) but it's definitely doing it. Clearly I'm going to have to do the head gaskets, but since I actually need the car to run around in I need to get it done as quickly as possible. I've not really done one of these before (although I've changed heads before), so here's the list of daft questions:

Do I need to get the heads skimmed? Up until now it's been going pretty well without losing more than the expected amount of oil or water. I can probably find someone to check them for flatness nearby but they'll take a while to skim them.

When Miah and I leakdown tested it a few months back it was about 20% evenly across all eight cylinders. Is it worth dropping the sump off and doing the piston rings too? That starts to get into doing bigend and main bearings as well, I guess?

If I do pull the pistons out and stick new rings in, what do I need to do about the bores? I've read various things about using those three-legged grinding stones and bogbrush type hones to break the glaze, presumably that's pretty important if I disturb that part?

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As a quick and dirty way I'd be inclined to pull the head off, check it for flatness and, assuming it is within spec, whack a new Elring gasket in there with a new set of stretch bolts. Make sure you clean the head and block faces properly. It'll get you back on the road in no more than a day (assuming it doesn't need to be skimmed). At worst it'll keep you going for a few thousand miles, or at least until the weather is more conducive to working on it. Hardest part is the manifold heatshield and bolts but you know that anyway.

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If you want fast and dirty, just do the minimums! Assuming it's not burning tons of oil leave the rings and shells for another day.
Head distortion can be checked yourself with a good straight edge. No more than 2 thou corner to corner and across the centres is LR tolerance. You'll have to make the call on a skim once you know it's warped (or eroded where the gasket blow is- longer you leave it, the more chance of burning the surface).
New valve stem seals and a quick lap of the valves should do the job.
I bought my head gasket set from Island. They supply one with Elring gaskets. New stretch bolts or ARP studs is up to you, but if you're going to strip it again in the future you may as well go with ARPs as they're approx twice the price of stretch.
EDIT- beaten by Gilbertd again!

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Manifold heatshield is long gone, returned to the ore from whence it came :-) I replaced the manifold bolts with stainless Allen bolts when I did the exhaust manifold gaskets last year, which makes it a doddle - even the one behind the steering column!

I think I'll just go with whipping the heads off and getting them checked for flatness, then.

Orangebean - I wish I knew where you were seeing ARP studs for twice the price of bolts, the only bolts I can find are Shitpart ones for a tenner a set (tempting, if I'm going to get back in there soon, but I suspect it'll be sooner than I'd like) and the cheapest 10-stud set I can find is £150!

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Ah yes, I could have been slightly out in my comparison! Half remembered from when I was doing my heads and justifying the cost of ARPs. Apologies.

Although genuine LR bolts appear to be £6 ish each (!) you can get OEM from LR Direct for 60-70p each, and you're only doing 1 head.
With ARPs you have to buy all 20 as a set. as you say, Real Steel at £152 seem about the cheapest UK supplier.

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I was wondering about only doing one side. I do expect to get back into it once the finances have recovered, so probably a ten quid blue box would be perfectly okay for the next few months.

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Local indy confirms that doing one side is just fine, and they have the bits I need in for 36 quid. Sounds like we have a winner.

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Get on with it then. Should have it done by about midnight.......

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Bits bought, except for the 5/8" socket :-) Let's see how it goes, dodging showers isn't really an option just now...

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If you've got a 16mm, 8 point spark plug socket for the smaller type plugs, then it's a perfect fit on the head bolts.

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I'll tell you what, the cam looks mint. There's a bit of a mark on the block though... :-/

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I'm sure it will clean off... You'd better not take all night doing it... Sloth and I are the record holders for the all nighters ;)

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It's actually cleaning up okay. After a bit of discussion with dhallworth who came out with more Jizer, silicone sealant and sympathy, I reckon I'd be daft not to just do both sides while it's as far apart as it is. There's quite clear evidence of a blow between cylinders 2 and 4, and between 6 and 8 (although nothing between 4 and 6). I wonder if that's where all my compression was going?

I had a couple of the cam followers out and while there are faint scuffs on the bottom - just enough to wipe off the machining marks - I can't see anything that looks like the pictures of worn cams or followers online. I'm coming to the conclusion that the cam must be pretty okay.

Slight blowing between cylinders wouldn't cause a loss of low-speed torque, would it?

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gordonjcp wrote:

Slight blowing between cylinders wouldn't cause a loss of low-speed torque, would it?

It would cause a lack of grunt right through the rev range but be more noticeable at lower revs. Much like running on 7 is noticeable at idle but once the revs are up it's just a slight lack of poke......

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Is it done yet?

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Not yet. Having found a fairly chunky blow between 2 and 4, and 6 and 8 (and of course the blow to atmosphere from 6) I'm considering taking the other head off for a look - for the sake of 30 quid for another gasket and set of bolts for that side, I may as well.

The tappets are a bit dished, but how much is too much? They're all smooth and shiny with no real wear marks on the cam but for example the number 8 exhaust tappet has its bottom dished by about 1mm, maybe a bawhair more.

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Does it make a lot of difference which valve goes in which cylinder, if I'm lapping them in anyway?

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Keep them matched up if you can. They'll have worked themselves in to their own seats and each will be slightly different in terms of contact area etc

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So kicking the box with the valves stabbed through the top across the kitchen and scattering them in all directions isn't that big a deal then :-D

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A bit of engineers blue to match up the contact areas should get them back in the right holes- only 4 options for each valve when you start :)