Great thread - I feel you pain / anxiety re the cracks around that stud. I was working on my son's car in our autumn and snapped an exhaust stud off below the block face - drilled it and tried an ezyout but snapped that too!. Wound my making a 10mm bracket to clamp the manifold at that point. Sigh - simple jobs get very complicated when working on older cars.

I saw this video in another thread

Might be worth a try.

Looks perfect for the task! Found some on the bay of fleas and will order: could be ideal. Similar to the alloy braze I've already got, but looks convincing on their ad! Let's see...

Will get on with some other tasks today then

HYS2000 on order and I've opened up the cracks with a triangular profile file. Let's see how this works, else I'll be trying to find a TiG welder!

rob_bell said:

I was thinking just to put it all together now - the stud isn't about to fall out, but I fear that that corner will ultimately fall off if left unattended.

Perhaps I'll drill the ends of the cracks to stop them extending and I'll think about some alloy braze: I have some low melting point aluminium rods here to try...

I'll have some thinks over night...

Click to expand...

Hi Rob, I think TIG is your best bet - it looks like it is cracked in at least 3 places and the cracks go down quite a way

It could be worse -I had that happen on a motor glider (AMF Chevvron 232 engine mount - König SD 570 just before lift off on the runway
That was a bolt - and was caused by hydraulic failure as the manufacturer had used a tad too much loctite. yikes... That was drilled down the cracks, end stopped and then the cracks welded and the whole thing re-drilled. We also ended up helicoiling it as the internal thread had been damaged by the 'outward' (pushing the stud out) force. Also had an airworthiness directive issued... - the bolt actually 'departed' the engine and it is only held in by three --..... it is quite disconcerting when the engine visibly shifts just before take off....

On closer inspection - yours looks like the stud has been tightened too much forcing the collar to split the boss apart. - it may also have stretched the internal threads.- is it equal thread both type both ends ? - and equal thread length - I have seen them inserted backwards sometimes (not on the K series as I am unfamiliar with that engine.)
What about asking your 'head' expert guy? .. I am sure he can stitch it.. or - if necessary - drill stops / drill out the cracks and then TIG. It may be good to weld out and in and re-drill / tap if needed - - you will know if that is needed as alloy will come out on the stud threads indicated an internal thread stretching damage....
Luckily - it is nowhere close to anything of great importance.

It sounds far more complicated than it is. For any good alloy casting welder it will be a piece of cake.
Just means a bit more delay but then at least you will be happy.
Joe

(edit - didnt see your other posts about the ebay stuff ) what ever you feel happy with. It is a not a critical stud at least...

Thanks Joe - the mode of crack in is as you describe, except I was using a torque wrench with just 15Nm dialled in. No over torqued, but presumably already cracked.

I'll try the braze with the stuff Alibro found: it seems an interesting product, plus, as you say, it isn't exactly a critical screw.

I'll attemp to drill stop - but access to the larger crack is extremely limited.

We shall see...

Another thought Rob - ALooy wheel repairers

rob_bell said:

Thanks Joe - the mode of crack in is as you describe, except I was using a torque wrench with just 15Nm dialled in. No over torqued, but presumably already cracked.

I'll try the braze with the stuff Alibro found: it seems an interesting product, plus, as you say, it isn't exactly a critical screw.

I'll attemp to drill stop - but access to the larger crack is extremely limited.

We shall see...

Click to expand...

Hi Rob,
It may well be ok with the soft braze stuff - I have used Durafix before (identical to the stuff in the video - they are all the same imo ) - and it was 'ok' it all depends on what you can get to. I have used it on a marine diesel heat salt water / fresh water exchanger. It seems quite impressive but be prepared to use quite a few rods getting the temps and condition correct. Also the cleanliness is vital. Use acetone and allow to dry or flash off with the torch (watch the eyebrows lol)
The only problem was - that I was not 100% convinced and if it had have been my heat exchanger I would have had it welded. (Just a mind f^ck thing really... - it was probably great - but ..... and it was rather important as water INSIDE a Yacht is NOT a good thing... )
The owner of the boat also decided to get it welded when he had access to an alloy casting fab / tig guy.
On yours, I think the difficulty is going to be in the areas I have marked on the image of yours (a part of re-posted here).
This area will be a fairly deep internal crack in the casting that you are unlikely to get the stuff into. TIG can easily get in there and at least bond the outside of the casting for perhaps 5 mm or so with a small groove whizzed out with the carbide / diamond cutter or similar in a die grinder.
It is the one sort of job that I think will be difficult for the Durafix to do it's stuff as the Durafix really needs surface area you can get to to effectively coat (a bit like solder tinning action) before any joining action or coating action. - but - again - maybe it will be ok and flow into the joints .. not something I had much success with but I was running out of rods as getting the heat right was a pain.... The other BIG issue may be actually getting heat into the area !!. (note all the 'demos' are on easily heated small pieces.). your cylinder head will act like a HUGE heat sink and getting the temp of the existing casting up will be extremely difficult - to say the least - also the trouble is if you open out the marked areas (which I believe need doing - then the casting piece may well fall off.. - Then it really is TIG. It is just a bit of a bu&&er to get to (from what I can see)
TIG can also provide an instant heat weld without the heat sinking issues of a low melt product.

here is the image of where (from what I can see and judge) I am sure it is quite cracked underneath and will only be held by a small surface area as the cracked 'chuck bent outward farther at the top - splitting the top / sides but would have cracked inside at the bottom area and bent slightly.
See how you go on. It will be really interesting how the stuff performs. I bet that heat exchanger is probably still going
I am not being negative - sorry if it seems that way - just looking at it from what I would do - however - I worry if there is a slight bit of oil on my engine - others never look under the bonnet and even if they do, some like the cruddy oil and diesel coating of some units as it "stops rusting and parts seizing" - or as an old guy said to me when we were live aboard sailing - (ref his old perkins 4107) 'If it aint got oil all over it there's summat wrong'...
He always said my Mercedes OM636 was far too clean - "must be summat up wi' it"...... (I kept the Merc' green paint hidden)

All true: I guess the proof of the pudding is in the eating! I'll let you know.

As respite, rather than getting the engine running as originally planned, I've been repairing the rear wheel carrier and high level brake light assembly. It needed doing, so at least I got one job done today!!!

rob_bell said:

All true: I guess the proof of the pudding is in the eating! I'll let you know.

As respite, rather than getting the engine running as originally planned, I've been repairing the rear wheel carrier and high level brake light assembly. It needed doing, so at least I got one job done today!!!

Click to expand...

- excellent - you didn't have my 'today's' issue then....... - had a puncture (my own stupid fault) went to get spare wheel off the carrier - probably first time since new in 1999 - in fact I am sure it was... and the bl00dy security nut was a different one to tall the others
Doh !
At least the carrier was clean and tidy underneath.. this 'no salt' thing here is a miracle compared to the UK..... I recommend it - I don' recommend stuffing a tyre bead off on a lump of granite though. .... might think about some inner tubes - - go 'old school'

Luckily no! Sorry to hear that Joe; nightmare

Nicely repainted rear wheel carrier back on the car:



And, although I can't use them as planned today, confirming the appearance of the OEM Kamax head bolts:

Drat: although I ordered the aluminium brazing rods at the weekend, the delivery won't be until next week At least another week's delay! Arrggghhh!!! It might have been faster to find a TiG welder from the outset, but this week has been so busy there would have been little chance to get it done over the week!

Bah.

Gives you loads of time to sort al the other issues then.

While I am still waiting for the braze to arrive, I thought I'd see whether I can get the boss up to temperature using my butane torch. Unfortuantely, the gas is nearly out, which won't have helped, but the highest surface temperature reached was 180C.

The thermal mass of the cylinder head is almost certainly wicking the heat away, as the cylinder head itself reached a nice toasty 50C.

In some YouTube videos, I can see that folks have put large castings into their garden BBQs. This starts to make much more sense, as you can get heat into the whole casting, and then add a little extra to the area you need.

Unfortunately I don't have access to a BBQ large enough.

So I dropped an email to a guy who does call out TIG welding, with experience in automotive work. I should have guessed when he revealed experience working on Ferraris, but his call out charge is £220.

I don't think so.

Oxy acetylene, or do I buy myself a TIG welder? At £220, I have seen cheaper inverters at around this price!

rob_bell said:

While I am still waiting for the braze to arrive, I thought I'd see whether I can get the boss up to temperature using my butane torch. Unfortuantely, the gas is nearly out, which won't have helped, but the highest surface temperature reached was 180C.

The thermal mass of the cylinder head is almost certainly wicking the heat away, as the cylinder head itself reached a nice toasty 50C.

In some YouTube videos, I can see that folks have put large castings into their garden BBQs. This starts to make much more sense, as you can get heat into the whole casting, and then add a little extra to the area you need.

Unfortunately I don't have access to a BBQ large enough.

So I dropped an email to a guy who does call out TIG welding, with experience in automotive work. I should have guessed when he revealed experience working on Ferraris, but his call out charge is £220.

I don't think so.

Oxy acetylene, or do I buy myself a TIG welder? At £220, I have seen cheaper inverters at around this price!

Click to expand...

Hi Rob, applying heat to the whole casting will almost certainly - end up in a disaster. A warped face and general distortion i the least- and after all that work. I wouldn't even contemplate it - not for one second. DONT DO IT SIR - PLEASE !

As for tig welders - ring around. Many places have them - usually any metal fabrication place, anyone that works with aluminium or stainless steel, any alloy wheel repairer etc etc. I think you would be hard pushed to find any metal fab place WITHOUT one.
Take the head to them and just call in - they usually will do a small job like that on the spot for beer money. I would have thought 20 quid maximum.
Joe

Might be easier to look for another head. Certainly cheaper than £220

Alibro said:

Might be easier to look for another head. Certainly cheaper than £220

Click to expand...

Yes, exactly. Actually, I could probably buy another Hippo for that money!

I'll work on the TIG option. This is getting spectacularly frustrating: the car should have been running last weekend

Joe, thanks for your suggestion. There is a metal fabricator on an industrial estate around the corner from where I live. The chap there said he'd look at it.

I suspect that I would not be the first: one of his first questions was whether the head was still in the car: he's obviously been caught out like that before! LOL

Might try to get home early and get there before he closes: unfortunately they're only open til 4pm. Else, I'll be looking at heading over on Wednesday morning...

rob_bell said:

Joe, thanks for your suggestion. There is a metal fabricator on an industrial estate around the corner from where I live. The chap there said he'd look at it.
I suspect that I would not be the first: one of his first questions was whether the head was still in the car: he's obviously been caught out like that before! LOL
Might try to get home early and get there before he closes: unfortunately they're only open til 4pm. Else, I'll be looking at heading over on Wednesday morning...

Click to expand...

Excellent Rob, that's the way to do it. - It will probably take him a very short time indeed.

Fingers crossed!

Sounds like a good plan. A proper welder will make it look easy where we would make a hash of it.