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[ScottieMV6]

Took some pictures of the heads now they are all stripped

1,2,3 Bank





[size=12]4,5,6 Bank - Little concerned about the deep gouge on the outside of number 6 cylinder which is where the HG appeared to have perished![/size]







And here are a couple of pics of how I kept all the followers, valves, springs collets etc in the right order!

[tunnie]

like the neatness labling all the bags 

That is a big chunk of metal missing there  - Maybe a replacement head as well as HG?

[ScottieMV6]

like the neatness labling all the bags 

That is a big chunk of metal missing there  - Maybe a replacement head as well as HG?

That was my fear! Is it worth even bothering to clean it up or has it had it? :-/

[Kevin Wood]

Hmm. That does look to have taken a nick out of the fire ring area. There's a big chunk out of the squish surface slightly inside the fire ring too. I wonder if that's foreign object damage or a result of coolant getting it.

Are there any marks on the piston crown of that cylinder?

I'd say that head needs a skim, at least. :-/

Kevin

[tunnie]

done a 2.2 HG before and that was slighly pitted, once skimmed was all silky smooth, but that does look very deep 

I am not sure on its affects, and how long a replacement HG would last  :-/

Considering the amount of V6's that get broken on here, realtive cheapness, maybe worth investing in another head if you intend to keep the car and get some miles out of it.

[Kevin Wood]

The damage that's actually on the fire ring area doesn't look too deep. If there's still a little nick on the face elsewhere it's not such an issue. Difficult to tell from a photo though.

I would say that's not a "slap it on with a new gasket" job though.

Kevin

[ScottieMV6]

Looks like I'll have to invest in a new head then.

Can I just get one or do I need the pair? I assume it needs to come with all the valves, followers etc to match?

[Kevin Wood]

I would take the head to a local engineering firm to get their opinion before condemning it, tbh. It's difficult to assess it without seeing it in the flesh and we might be worrying about nothing. If it can be skimmed it should be a relatively cheap fix.

Assuming the other head is OK I see no reason not to change just the one. I believe there were differences in the oil pump design which necessitated changes to the lifters and the oil supply valve in the head, so I would either try to get a head from a similar model year or swap these parts from the old head.

See if the old head can be resurrected first though.

Kevin

[ScottieMV6]

I would take the head to a local engineering firm to get their opinion before condemning it, tbh. It's difficult to assess it without seeing it in the flesh and we might be worrying about nothing. If it can be skimmed it should be a relatively cheap fix.

Assuming the other head is OK I see no reason not to change just the one. I believe there were differences in the oil pump design which necessitated changes to the lifters and the oil supply valve in the head, so I would either try to get a head from a similar model year or swap these parts from the old head.

See if the old head can be resurrected first though.

Kevin

I thought I had read that the V6 heads shouldn't be skimmed? :-?

[JamesV6CDX]

I would take the head to a local engineering firm to get their opinion before condemning it, tbh. It's difficult to assess it without seeing it in the flesh and we might be worrying about nothing. If it can be skimmed it should be a relatively cheap fix.

Assuming the other head is OK I see no reason not to change just the one. I believe there were differences in the oil pump design which necessitated changes to the lifters and the oil supply valve in the head, so I would either try to get a head from a similar model year or swap these parts from the old head.

See if the old head can be resurrected first though.

Kevin

I thought I had read that the V6 heads shouldn't be skimmed? :-?

I have personally done it - with sucess.

the reason they shouldn't be skimmed if possible, is to avoid alignment issues with the inlet divider and coolant bridge, more than anything else, so skimming should be kept to a minimum, but it can certainly be done.

Timing is not a problem, because the idlers are concentric and can take up the slack, though bear in mind you wouldn't be able to use a fixed idler kit, as per some 2.6 and 3.2.. (and my crossbreed 2.5!)

[JamesV6CDX]

If the car is a 3.0, you can use a head off any 3.0. Try and get one the same age if you can, if you do need to replace it - but it's not essential.

If using one of a different era, you will need to transfer your T vents from the old head, to match the oil pump fitted in the car and give the correct oil feed. A really easy job and we can show you how.

In all instances, if getting a new head - you will need to ensure the camshaft bearing caps come with the new head - they are machine line bored and therefore specific to each individual head. You can still use your existing camshafts, though...

[Kevin Wood]

Yep, V6 heads shouldn't be skimmed as a matter of course, as it is normally unnecessary and can cause issues if too much is taken off.

However, 10 thou or so off the head shouldn't noticeably affect timing or inlet alignment, the former being adjustable on earlier cars anyway.

Kevin

[Kevin Wood]

In all instances, if getting a new head - you will need to ensure the camshaft bearing caps come with the new head - they are machine line bored and therefore specific to each individual head. You can still use your existing camshafts, though...

Oh, yes. Very important, that one. Mate of mine ended up stranded in the middle of Arizona with a Sierra Cosworth cam in 3 pieces due to that little gem.

That was after some hillbilly who's clearly used to working on more agricultural Big Blocks knackered his previous head by skimming about half an inch off it.

Kevin

[ScottieMV6]

Just got off the phone with a local place who says he will have a look at them for me and advise whether they can be skimmed. If they can he'll charge £25 per head to do them.

Is it ok to just have the one skimmed as long as he takes no more than 10 thou off?

I don't like using places that i don't know and I'm wondering whether its worth just getting a new head from someone on here that I trust? :-/

[Kevin Wood]

See what feeling you get from them.

They should know what can be safely skimmed from the heads by measuring the current heads and comparing with a minimum depth that will be in a manual somewhere. They should also be able to estimate by the damage how much will need to come off.

Don't take my 10 thou figure as gospel, by the way. They could probably take off considerably more, but they should be able to tell you what the min. thickness is for that engine and they should be working to it.

If they appear to be "winging it" it might be better to get a replacement head.  :-/

Skimming will probably get you back on the road quicker, though.

Whether you can get away with skimming one head depends on how much mismatch can be taken up by the intake divider. Gut feeling says you will get away with it but to be honest, I don't really know. If they know what they are doing they'll be able to advise you on that too.

Kevin