Disco 2 Blowing exhaust manifold, again. Probably need new cylinder head; what am I looking at?

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I think one of the most important things you seem to have shown with your photo is the use of brass or is it copper nuts. Long, long time ago an exhaust guy told me about brass nuts, they make all the flipping difference in the world. Yet another thing that peees me off about manufacturers, why can't they put them on as standard? A few pence to them but pounds down the line to the poor old end user.
 
Stanleysteamer said:
I think one of the most important things you seem to have shown with your photo is the use of brass or is it copper nuts. Long, long time ago an exhaust guy told me about brass nuts, they make all the flipping difference in the world. Yet another thing that peees me off about manufacturers, why can't they put them on as standard? A few pence to them but pounds down the line to the poor old end user.
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Looks copper to me; surely that's really soft and inclined to fail? Or is that the point - the nuts fail and not the studs/head?
 
Si Click said:
They are copper plated steel, as supplied standard with a Wurth HD stud kit.
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...thus allegedly combining the rust preventative qualities of copper, (brass is an alloy of copper and zinc so has similar properties) with the strength of steel. Silicon bronze would be the best combination of corrosion resistance and strength but would be a lot more expensive. Stainless would be good too but again there is the question of work hardening and stainless is not totally rust resistant. I suppose Wurth are relying on the fact that you would not be tightening them up too often so the coating would last a fair time as opposed to being worn away by the action of the socket or spanner. Brass is softer, no denying it, but this only matters where great stress is on the component. I cannot remember offhand the torque applied to these nuts but I seem to remember it is less than 20 lbs/foot which is not much, so brass would be OK.
 
Torqued to 20 lbs/ft.

All bar the lower central two anyway which I could only get access with a 3/8" drive. Those were done by feel as I don't have a 3/8"torque wrench.
 
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That insert shown in the first pic looks a bit proud to me. Is it allowing the manifold to sit against the head? Good job though.
 
iansoady said:
That insert shown in the first pic looks a bit proud to me. Is it allowing the manifold to sit against the head? Good job though.
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That's a good point! Might need a touch with a grinder. although it might just sit in the two gaskets. Re the 3/8 socket, do you not have a 1/2 to 3/8 converter? The torque could still be measured that way, unless someone is going to come on here and dispute that. From an engineering point of view I believe altering the size of the drive is only the same as altering the size of the fulcrum i.e. it has no bearing on the amount of torque it takes to do up the nut. I'll h ave to think about this!
 
Stanleysteamer said:
...thus allegedly combining the rust preventative qualities of copper, (brass is an alloy of copper and zinc so has similar properties) with the strength of steel. Silicon bronze would be the best combination of corrosion resistance and strength but would be a lot more expensive. Stainless would be good too but again there is the question of work hardening and stainless is not totally rust resistant. I suppose Wurth are relying on the fact that you would not be tightening them up too often so the coating would last a fair time as opposed to being worn away by the action of the socket or spanner. Brass is softer, no denying it, but this only matters where great stress is on the component. I cannot remember offhand the torque applied to these nuts but I seem to remember it is less than 20 lbs/foot which is not much, so brass would be OK.
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... should have said "less than or equal to"!!! Was from memory after 2 years!
 
On blowing up you (very high quality) pic I have to agree with @iansoady. I think it would be a massive pain to take the whole thing off again just to slightly drill out a bit of the face of the manifold and the gaskets to take the extra width/height, but it would probably be the easiest thing to do. I don't imagine you'd want to go in their with a grinder, after all the trouble you have had. and what are the 4 clippy-looking things set every 90 degrees round the top of the insert? Something to do with the fitting of it? Very interesting. Again, they might be important and you wouldn't want to go interfering with them.
Or, you could simply leave it as it is, and find a way of testing to see if that part of the manifold is still leaking. I had to do this after I put mine back on and it wasn't easy as a wet finger was being blown at from the fan, but I managed in the end to shield it enough to test it that way. Some kind of smoke generator might be more efficient.
Anyway, I am assuming you have put it all back together now and have no desire at all to peese on your parade. I remember how happy I was after putting it all back together and driving around with no whistling sound, so good on you and enjoy it.

Wonder if @Naf623 is having any better luck?
 
Stanleysteamer said:
Wonder if @Naf623 is having any better luck?
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Car is going in next week so my garage can take the head off and I'll take it to a local-ish guy who might be able to spark erode the original hole clean and skim the manifold. He does engine rebuilds and head refurb, so if he can't then I'll have to look at a refurbished head from somewhere instead.

Currently trying to work out what head gasket kit I need... eBay wants to tell me this wont fit my engine (15p, I've discovered); but is it only the rocker cover gasket that's different? The description suggests they can supply either, so I'm confused.
 
Naf623 said:
Car is going in next week so my garage can take the head off and I'll take it to a local-ish guy who might be able to spark erode the original hole clean and skim the manifold. He does engine rebuilds and head refurb, so if he can't then I'll have to look at a refurbished head from somewhere instead.

Currently trying to work out what head gasket kit I need... eBay wants to tell me this wont fit my engine (15p, I've discovered); but is it only the rocker cover gasket that's different? The description suggests they can supply either, so I'm confused.
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When you look at "compatible vehicles" it gives the dates as earlyish, thus covering the 10p engine, but if it is only the rocker cover gasket, you can get one of those cheaply enough and run with the one you've got in the meantime, it's not a big deal. Can't your engine rebuilder/garage get waht you need and at trade rates? Or would that be ridiculously expensive?

Anyway, good luck with getting it all sorted. glad you ain't gone with the secondhand head!
 
tilly2 said:
If its not blowing, just leave it...
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The insert does not sit proud but is slightly recessed with the forks just at the level of the hole. It is not blowing and is running fine. I will leave it.

Stanleysteamer said:
Re the 3/8 socket, do you not have a 1/2 to 3/8 converter?
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Do you know, that never occurred to me. I'm pretty happy I did not over torque them, but I plan on checking the torque in a 100 miles or so and I will see if I can get access with a converter. Cheers.
 
IIRC I needed about a 6" extension bar, but it may have been a bit longer to get it under the connection to the turbo. but it can all be done although a bit fiddly, as you well know!
 
Stanleysteamer said:
When you look at "compatible vehicles" it gives the dates as earlyish, thus covering the 10p engine, but if it is only the rocker cover gasket, you can get one of those cheaply enough and run with the one you've got in the meantime, it's not a big deal. Can't your engine rebuilder/garage get waht you need and at trade rates? Or would that be ridiculously expensive?

Anyway, good luck with getting it all sorted. glad you ain't gone with the secondhand head!
Click to expand...

My garage just gets everything from Andrew Page, so while it's quality stuff, its really expensive.
 
Well I am not the only person who rates brass nuts.
https://www.tr-register.co.uk/forums/index.php?/topic/37869-exhaust-manifold-to-cylinder-head-nuts/
and here if you read far enough
https://www.pistonheads.com/gassing/topic.asp?h=0&f=66&t=1288012
and here
https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=953994
At the very least, use nickel based anti-seize compound. The copper coating on the thread will wear off as you torque them up, especially if you are putting them onto old rusty studs, although they may not rust quite so easily. As I said it was an exhaust guy who recommended brass nuts to me and I have never had a problem since I started using them. But then put 10 car guys in a room and you'll get 10 differing opinions!
 
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