Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[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

[ScottieMV6]

Ok. Thanks for the advice Kev.

[Marks DTM Calib]

Given the low value of a pair of 3.0 heads second hand...it might be worth sourcing a set of second hand heads (about 40-50 quid a head tops)

The damage in the quish area looks to be either foreign object (but, you normaly get more than one impact mark) or a casting failure....if the latter then a skim is pointless.

You could change just one head for a second hand one but....if skimming you need to do both heads to keep the compression ratios constant on all 6 cylinders

[ScottieMV6]

Given the low value of a pair of 3.0 heads second hand...it might be worth sourcing a set of second hand heads (about 40-50 quid a head tops)

The damage in the quish area looks to be either foreign object (but, you normaly get more than one impact mark) or a casting failure....if the latter then a skim is pointless.

You could change just one head for a second hand one but....if skimming you need to do both heads to keep the compression ratios constant on all 6 cylinders

What is the quish area?

[Marks DTM Calib]

The squish area is the section in the cylidner inside of the head gasket fire ring....its the bowl which the fuel/air mix is comrpessed into at the top of the compression stroke

[ScottieMV6]

Have I got this diagram labelled up right? (sorry but I am still learning)



If that is correct then is this the damage in the squish area you were talking about?



If so then this is not damage but an oil smear. It is now gone!

Finally I have also found this damage on cylinder 2



What are the chances of this sort of damage being repaired?

[Kevin Wood]

If so then this is not damage but an oil smear. It is now gone!

LOL that just goes to show how hard it is to diagnose from photos.

I think you have got the terminology right. Now, bear in mind that the fire ring area is the critical part of the gasket. This must compress the metal fire ring on the gasket to form a very strong seal to contain the combustion pressures. If there is any damage to this part of the cylinder head the gasket will blow again. Elsewhere, little nicks are not such an issue because the composite gasket material has a little more give in it, there is less pressure to contain and the gasket has sealant impregnated into it.

I would first get rid of the traces of old gasket and oil by scraping with a wooden or plastic implement and then perhaps a light rub down with a fine emery cloth. Then see if there is any pitting or narrowing of the fire ring areas.

Kevin

[megaomega123]

This is a very interesting thread. Can I ask Scottie, did you do all the strip down with the engine in situ or did it come out? Just out of interest 

[Bent valve]

Have I got this diagram labelled up right? (sorry but I am still learning)



If that is correct then is this the damage in the squish area you were talking about?



If so then this is not damage but an oil smear. It is now gone!

Finally I have also found this damage on cylinder 2



What are the chances of this sort of damage being repaired?

Are you sure thats an oil smear? I would have bet money on that being a porous casting :-?

[Marks DTM Calib]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

[ScottieMV6]

This is a very interesting thread. Can I ask Scottie, did you do all the strip down with the engine in situ or did it come out? Just out of interest 

Strip down was done with the engine in situ.

[ScottieMV6]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

[tunnie]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

I found using razor blades cleans the old gasket off well 

[Kevin Wood]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

I found using razor blades cleans the old gasket off well 

A scotchpad from a plumber's merchants is not a bad investment either.

Kevin

[ScottieMV6]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

I found using razor blades cleans the old gasket off well 

A scotchpad from a plumber's merchants is not a bad investment either.

Kevin

I got 2 of those yesterday!

[Marks DTM Calib]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

I found using razor blades cleans the old gasket off well 

A scotchpad from a plumber's merchants is not a bad investment either.

Kevin

I use the ones that magicaly appear in the cupboard....for both plumbing and cleaning head faces.

But yes, you need a blade to get the crudd off first, I have an old chisel that I use

[Dishevelled Den]

What an interesting thread - very informative indeed.

Hope you're up and running before too long Scottie - well done for doing the job yourself 8-) 8-)

[Kevin Wood]

I use the ones that magicaly appear in the cupboard....for both plumbing and cleaning head faces.

I seem to be the only one who uses them in this house. Not for cleaning heads, more's the pity.

 

Kevin

[ChevetteNick]

those heads are scrap mate if your keeping the car. they definately need welding between the water chambers and they also need to be perfectly flat across the whole face otherwise the gasket will leak. they're a perfect example of neglected coolant/corrosion inhibitor.

[ScottieMV6]

those heads are scrap mate if your keeping the car. they definately need welding between the water chambers and they also need to be perfectly flat across the whole face otherwise the gasket will leak. they're a perfect example of neglected coolant/corrosion inhibitor.

Nick

Perhaps you could explain a little more why you see them as scrap.

I am not trying to be rude but you are a relative newbie here and MDTM (who has a lot of experience with these heads) seems to think they will be ok.

As I said not being rude but I have no idea of your experience

[ScottieMV6]

What an interesting thread - very informative indeed.

Hope you're up and running before too long Scottie - well done for doing the job yourself 8-) 8-)

Thanks Zulu.

I hope it will be of help to someone else in the same situation as me!

[Marks DTM Calib]

those heads are scrap mate if your keeping the car. they definately need welding between the water chambers and they also need to be perfectly flat across the whole face otherwise the gasket will leak. they're a perfect example of neglected coolant/corrosion inhibitor.

Nick

Perhaps you could explain a little more why you see them as scrap.

I am not trying to be rude but you are a relative newbie here and MDTM (who has a lot of experience with these heads) seems to think they will be ok.

As I said not being rude but I have no idea of your experience

The reason why I say they are not is because I also have knowledge of the block area......the small areas where the corrosion is evident correspond to a water jacket opening on the block.

As for flat, I am yet to see a warped V6 head but, its easy enough to check with a good straight edge and a light source.

The key part I look for is presence of plenty of meat between the fire ring point and the coolant jacket and damage across the full surface.

A final tip for the last stage of cleaning......fine wet and dry (wet) plus a block of wood. 

[ChevetteNick]

Nick

Perhaps you could explain a little more why you see them as scrap.

I am not trying to be rude but you are a relative newbie here and MDTM (who has a lot of experience with these heads) seems to think they will be ok.

As I said not being rude but I have no idea of your experience

Yeah no problemo mate I think I'd be the same so I'll give you a little bit of my background to put you at ease
I am an apprentice trained (4 years City & Guilds) engine remanufacturer. I spent a total of 8 years in the game, only leaving because i was never going to be anything other than a kid in their eyes, and have resurrected BL 'A' series (common) engines to Aston Martin V8s (rare) and everything inbetween even pre-war engines couldn't defeat me.
Now let me explain why I would scrap your heads. The Japanese, as they do, revolutionised the way engines were made and the life expectancy of them. The Ford Pinto 2.0 ohc could be rebored 6 times before fitting liners and taking it back to the original bore size and the crank could be reground 4 times before it was scrapped or even metal sprayed to prolong its life. Toyota on the other hand had their engines re-manufactured as part of a service interval. So when the car was on its last legs the engine couldn't live for much longer as their engines only have a short lifecycle....a new engine design would have been brought out making parts for the old one really hard to get. These 2 engines were used as an example as they were both available at the same time. Everyone else now makes engines the same way so you can't get the life out of them that you used to. Your heads are common enough still for you to be able to fit new(er) ones. Look at this picture of the area I have pinpointed.



Water has corroded this area, head gasket failure, and will only get worse. Just having the head skimmed, it won't clean it up enough, and re-fitting it isn't going to achieve anything other than head gasket failure. This area and all the others like it needs to be welded first and if this is succesful, rotten aluminium is notoriously bad at taking a weld...and don't get me started on the quality of the alloy, then you'll be ok but it just isn't worth it in my opinion  

[Andy H]

What you cannot see from Scotties photo is that the corroded area presses against a piece of headgasket but there is a coolant passage the other side of the headgasket.

The fire ring stops on the edge of your red box so the important areas of the head appear to be unscathed.

That said, with good used heads being currently easy to obtain there is no point in trying to use the heads if they are suspect.

[Bent valve]

Nick

Perhaps you could explain a little more why you see them as scrap.

I am not trying to be rude but you are a relative newbie here and MDTM (who has a lot of experience with these heads) seems to think they will be ok.

As I said not being rude but I have no idea of your experience

Yeah no problemo mate I think I'd be the same so I'll give you a little bit of my background to put you at ease
I am an apprentice trained (4 years City & Guilds) engine remanufacturer. I spent a total of 8 years in the game, only leaving because i was never going to be anything other than a kid in their eyes, and have resurrected BL 'A' series (common) engines to Aston Martin V8s (rare) and everything inbetween even pre-war engines couldn't defeat me.
Now let me explain why I would scrap your heads. The Japanese, as they do, revolutionised the way engines were made and the life expectancy of them. The Ford Pinto 2.0 ohc could be rebored 6 times before fitting liners and taking it back to the original bore size and the crank could be reground 4 times before it was scrapped or even metal sprayed to prolong its life. Toyota on the other hand had their engines re-manufactured as part of a service interval. So when the car was on its last legs the engine couldn't live for much longer as their engines only have a short lifecycle....a new engine design would have been brought out making parts for the old one really hard to get. These 2 engines were used as an example as they were both available at the same time. Everyone else now makes engines the same way so you can't get the life out of them that you used to. Your heads are common enough still for you to be able to fit new(er) ones. Look at this picture of the area I have pinpointed.



Water has corroded this area, head gasket failure, and will only get worse. Just having the head skimmed, it won't clean it up enough, and re-fitting it isn't going to achieve anything other than head gasket failure. This area and all the others like it needs to be welded first and if this is succesful, rotten aluminium is notoriously bad at taking a weld...and don't get me started on the quality of the alloy, then you'll be ok but it just isn't worth it in my opinion  

Do you mean to say that when you took your Toyota in for a service they remanufactured the engine because it was shit and not as good as a ford engine? :-?

[ScottieMV6]

Nick

Perhaps you could explain a little more why you see them as scrap.

I am not trying to be rude but you are a relative newbie here and MDTM (who has a lot of experience with these heads) seems to think they will be ok.

As I said not being rude but I have no idea of your experience

Yeah no problemo mate I think I'd be the same so I'll give you a little bit of my background to put you at ease
I am an apprentice trained (4 years City & Guilds) engine remanufacturer. I spent a total of 8 years in the game, only leaving because i was never going to be anything other than a kid in their eyes, and have resurrected BL 'A' series (common) engines to Aston Martin V8s (rare) and everything inbetween even pre-war engines couldn't defeat me.
Now let me explain why I would scrap your heads. The Japanese, as they do, revolutionised the way engines were made and the life expectancy of them. The Ford Pinto 2.0 ohc could be rebored 6 times before fitting liners and taking it back to the original bore size and the crank could be reground 4 times before it was scrapped or even metal sprayed to prolong its life. Toyota on the other hand had their engines re-manufactured as part of a service interval. So when the car was on its last legs the engine couldn't live for much longer as their engines only have a short lifecycle....a new engine design would have been brought out making parts for the old one really hard to get. These 2 engines were used as an example as they were both available at the same time. Everyone else now makes engines the same way so you can't get the life out of them that you used to. Your heads are common enough still for you to be able to fit new(er) ones. Look at this picture of the area I have pinpointed.



Water has corroded this area, head gasket failure, and will only get worse. Just having the head skimmed, it won't clean it up enough, and re-fitting it isn't going to achieve anything other than head gasket failure. This area and all the others like it needs to be welded first and if this is succesful, rotten aluminium is notoriously bad at taking a weld...and don't get me started on the quality of the alloy, then you'll be ok but it just isn't worth it in my opinion  

Thanks for taking the time to explain Nick and give me an idea of your background.

Due to the fact that I am not flush at the moment I am going to take my chances with what I have got. I might regret that in 6 months time (or even sooner) but right now I can't justify spending the money on new (second hand) heads for what is a second car that barely does 2000 miles a year!

[Marks DTM Calib]

You wont have any issues with them.....

[Marks DTM Calib]

Here is the best pic I have of the block face...

[ScottieMV6]

Thanks Mark.

I had a look at the block face on mine yesterday to try and get an idea of what you meant. I see exactly what you are saying now, the part of the head that is corroded corresponds exactly with the waterway in the block where there is no metal

[Marks DTM Calib]

Thanks Mark.

I had a look at the block face on mine yesterday to try and get an idea of what you meant. I see exactly what you are saying now, the part of the head that is corroded corresponds exactly with the waterway in the block where there is no metal

Correct, and hence there is no support or clamping offered in that area anyway

[ChevetteNick]

Do you mean to say that when you took your Toyota in for a service they remanufactured the engine because it was shit and not as good as a ford engine? :-?

Um no I don't. It was deemed by Toyota that at a certain mileage it would have worn outside their tolerances and so needed to be rectified.

[Kaycee]

yes and they dont make good accelerators neither

[Proz]

yes and they dont make good accelerators neither

  ..... nice one