Euro cruise disaster

Pingu said:
Using bolts on a cylinder head is always a poor design compromise, especially if the material being screwed into is soft. It's usually due to making manufacture easier in the factory. Bolts tighten in a totally different way to studs and nuts.

A cylinder head to block fastener only needs to be in tension. A bolt tries to twist the thread out of the block, a stud tries to pull the thread out of the block.
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I have seriously considered this modification as I agree with your comment. I would have to make my own studs from M10 x 1.5 pitch, grade 12.9, 130mm long socket screws, which is easy enough to do, but after further investigation I have found that I wouldn't be able to tighten the nuts, as there isn't enough room to accommodate the socket. Thank you for the tip though, I really thought it was an easy and very practical solution to over stressing my already over stressed threads.

Another really helpful tip from this brilliant forum. Thanks again, it's really appreciated
 
As an aside and probably a dumb question but: When lifting an engine out or into the car using lifting eyes mounted on the cylinder head the engine weight is then presumably hanging off the cylinder head. Does this impact any additional stretch/stress on stretch bolts taking them past their torque to yield point and weaken the head gasket seal?
 
Very unlikely I would imagine as it's more than likely that the engine(s) being lifted would be stone cold?

Tony.
 
Synclare said:
As an aside and probably a dumb question but: When lifting an engine out or into the car using lifting eyes mounted on the cylinder head the engine weight is then presumably hanging off the cylinder head. Does this impact any additional stretch/stress on stretch bolts taking them past their torque to yield point and weaken the head gasket seal?
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No Adrian, it wouldn't put any undue stresses on the cylinder head bolts. An engine weighs approx. 150kgs I would guess. Each engine bolt @ 10mm dia and grade 12.9 has a breaking load in excess of 8 tonnes, with a yield point at approx. 85% of that. Yield of each bolt is approx. 6.8 tonnes. So as there are 16 bolts holding the head to the block they have a total yield of over 100 tonnes in round figures.
 
Sean d said:
Are you doing the VANOS seals whilst you are in there mate
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Yes I'm doing the vanos. I was hoping to have had it done by now as it's all stripped ready to go, but I just haven't got round to it yet.

I'll do some photos and add them to this thread as I go.
 
Jack Ratt said:
I have seriously considered this modification as I agree with your comment. I would have to make my own studs from M10 x 1.5 pitch, grade 12.9, 130mm long socket screws, which is easy enough to do, but after further investigation I have found that I wouldn't be able to tighten the nuts, as there isn't enough room to accommodate the socket. Thank you for the tip though, I really thought it was an easy and very practical solution to over stressing my already over stressed threads.

Another really helpful tip from this brilliant forum. Thanks again, it's really appreciated
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However ...........

If I stripped the cam carriers and cams from the head, then maybe I would have sufficient access to get a socket onto the nuts on the studs. I could then fit the head and then refit the cam carriers and the cams in situ.
Care would be needed to ensure I had clearance between the pistons and valves when I rotated the cams to refit the bearing caps. As long as I remember to turn the crankshaft approx. 30 degrees backwards it should give me enough clearance between pistons and valves to do this.

I need to think this through, but it just might be possible.
 
Jack Ratt said:
However ...........

If I stripped the cam carriers and cams from the head, then maybe I would have sufficient access to get a socket onto the nuts on the studs. I could then fit the head and then refit the cam carriers and the cams in situ.
Care would be needed to ensure I had clearance between the pistons and valves when I rotated the cams to refit the bearing caps. As long as I remember to turn the crankshaft approx. 30 degrees backwards it should give me enough clearance between pistons and valves to do this.

I need to think this through, but it just might be possible.
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You can see why they use bolts at the factory;).
 
Back when I changed my valve guide oil seals without taking the head off it wasn't too tricky getting the cams back in and timed up, just got to be careful (obviously). Found some very helpful videos on youtube about it, haven't got time to go looking now, supposed to be working.:whistle:
 
the Nefyn cat said:
Back when I changed my valve guide oil seals without taking the head off it wasn't too tricky getting the cams back in and timed up, just got to be careful (obviously). Found some very helpful videos on youtube about it, haven't got time to go looking now, supposed to be working.:whistle:
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Thank you for the support, I've done a bit of research and have got a few tips from YouTube vids so I know it's possible to do it. As you say, I just need to be a little careful.

I've ordered the long bolts to make the studs from, but I'm struggling to find some 12.9 grade flange nuts to suit them. Looks like I'll have to settle for 12.9 grade full nuts instead.
 
Jack Ratt said:
Thank you for the support, I've done a bit of research and have got a few tips from YouTube vids so I know it's possible to do it. As you say, I just need to be a little careful.

I've ordered the long bolts to make the studs from, but I'm struggling to find some 12.9 grade flange nuts to suit them. Looks like I'll have to settle for 12.9 grade full nuts instead.
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I'd suggest that you don't want flanged nuts. Nuts and washers is a better solution.

Flanged nuts "rip" at the surface when they are tightened. It doesn't matter if a "Nuts and washer" nut "rips" at the washer. The washer won't "rip" at the aluminium head unless it is turned by the nut.

I hope this makes sense.
 
@Pingu thank you for your comment,

I was thinking of using flange nuts to imitate the surface area that the original head bolts would have, to apply the clamping torque to each of the standard cylinder head washers.
However a standard M10 nut which is 17mm across the flats is probably very near to the standard head bolt anyway.
If I used flange nuts, they wouldn't be in direct contact with the head as I am still going to fit the standard steel head washers.

I'm open to any suggestions you guys might put forward
 
Jack Ratt said:
@Pingu thank you for your comment,

I was thinking of using flange nuts to imitate the surface area that the original head bolts would have, to apply the clamping torque to each of the standard cylinder head washers.
However a standard M10 nut which is 17mm across the flats is probably very near to the standard head bolt anyway.
If I used flange nuts, they wouldn't be in direct contact with the head as I am still going to fit the standard steel head washers.

I'm open to any suggestions you guys might put forward
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You can get plain flange nuts with a "flat" type washer face?

Tony.
 
I'm struggling to find any type of flange nut in grade 12.9. Standard 12.9 full nuts are readily available though and will be ok.
 
Jack Ratt said:
I'm struggling to find any type of flange nut in grade 12.9. Standard 12.9 full nuts are readily available though and will be ok.
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Hope you find what you need to do the mod mate it will give you confidence in the repair I think.

Tony.
 
Brief update
I've made and fitted my engine block studs and then I fitted the cylinder head on the block. Then as I was putting the washers and nuts on the studs I noticed that I might not be able to get a 17mm socket onto 4 of the 14 studs because of the positioning of the cam carrier mountings.

Not a major problem, just need to trim a bit of the metal way with my Dremel. So got the Dremel out and found I hadn't got any suitable grinding bits or milling bits. A quick trip to Halfords and B&Q and found they didn't have any either, so got back home and ordered some on Ebay.

I've taken the head back off the engine block so that I have easier access to work on it.

I really wanted to get the head torqued down this weekend, but it's not to be. It's freezing cold in the garage anyway so I was glad to get back into the house.
 
Good luck mate.
 
I did the little modification that I mentioned in post 337 and then I decided to accept the advice one you guys offered, sorry but can't recall who it was, earlier in the thread about helicoiling all of the holes and not just the 4 that pulled. so I did that without too much trouble. The 2 holes at the rear of the engine block were a bit tight, space wise, but my new drill did the job nicely.

20180311_111912.webp


I even invented a new tool to suck out the swarf from the holes in the engine block. @t-tony will like this =))

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I taped a straw to the Henry hoover sucker thing and it works a treat.

Then I successfully fitted all the studs, fitted the cylinder head and torqued it down nicely

20180316_130911.webp
 
That's as far as I've got at the moment. We had a family bereavement recently, we lost my nephew who was also my first Godson to Motor Neurone Disease, so there are other more important things taking my time, but I'll be back on it as and when, or really when I can be arsed to do it.
Next job is to refit the cams and vanos and once that's done, we're nearly there.
 
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