You must inspect all the studs. Rust “necks” them down to varying fractions of full diameter. With what you have found in the waterways there will almost certainly be rusty studs. I would (and recently did) remove all and replace. A set includes one “dowel stud” which has a bigger diameter to dowel locate the head in the correct place. We can talk you through all you will find. Paul
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As Paul says, Graham, it is advisable to inspect the studs…
…even slight rust damage to the studs will weaken them - and you do not really want snap a stud when you refit the head. While the studs already removed may be in perfect condition, it does not guarantee the others. And since the ‘patient’ is already open - inspecting and eventually renewing the studs is cheap insurance…
Frank
xj6 85 Sov Europe (UK/NZ)
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Thanks all i’ll replace the studs no problem.
Any tips on how to get the inlet manifold off the head?
I’ve soaked it in WD40 for the last two days and it won’t budge.
Try some Seafoam Deep Creep. Works better than WD40 in my opinion. Or PB Blaster.
Jeff
removing the studs, by double-nutting using ground to 3/4 thickness nuts will help, if possible
dont break any though!..some heat and or rapping may help free the stud
Correct: WD40 is not primarily meant to penetrate rusted threads.
PB Blaster, Kroil, and Knock’er Loose are the best commercial ones. One can mix ATF and/or diesel and acetone for a good homebrew one.
Hi all, manifold came off with some gentle heat and some ratchet straps for sideways pressure.
The head went away to be skimmed but apparently it was not nessesry (result)
Everything is now cleaned, flushed and ready to be put back.
I have new studs of 4 different lengths 7,3,3 &1 and I have finger tight replaced them like for like.
Is there a picture anywhere with the sequence they should go as the engine lifting bracket studs are different sizes and the shorter stud of the two has the plug lead bracket as well, which in my logic is incorrect.
I guess I have
1 short locator stud
3 short corner studs
3 longer studs for engine lifting bracket ?
7 standard length studs
Any advice before I fit everything this weekend?
The most important thing is to make sure that the receiving threads - at the bottom of the block - are clear and free to bottom the studs. Can’t stress this enough. I used a 7/16 UNF tap welded to a “T” bar. Bottoming repeatedly cleans the thread and removes all the crud. This way the very top of the stud presenting at the top of the cylinder head will be the correct height to receive and tension the domed head nuts. Have seen multiple engines with extra washers to “pack off” so the nuts tension properly. Also make sure that there is no remaining liquid in the threads - you don’t need to be fighting water as you wind them in! Paul
Thanks Paul
The studs were put in finger tight in a dry block with the air hose directed through the core plug holes into the thread so hopefully I’ve got everything out.
Still a niggling feeling about the studs in the right order though!
Graham
I can send a picture of my '72 S1 if that is of any help - with lifting points etc? Paul
Thanks Paul
I know where they go, I can’t work out why there would be only 3 long studs in the set and not 4?
Graham
Here’s the parts plates:
Note the tables showing head stud length.
I suspect you may have a stud set for a late engine (7L.66598).
What block/head have you got? Someone may have been mixing and matching before you opened it up.
Thanks Andrew
I should be able to work it out now
Cheers
Graham
Very interesting thread, that will soon be of great value to me.
Do you advise lacing the bottom thread of the studs with some Loctite glue or just tighten strongly with a double nut?
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Both are likely overkill, Eric - just ensure the studs are fully seated…
Frank
xj6 85 Sov Europe (UK/NZ)
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