ooops - stripped thread, advice please

[pheasant]

Oh dear, been a bit of a silly chap. I stripped a thread on the manifold to cylinder head

I had removed the manifold in order to have a crack tigg'd, all the nuts came off very easily leaving studs in situ, apart from the rearmost which was an Allen key screw ? 1st question, should it have been? However this too came out easily.

Fast forward, manifold repaired and refitted with new gasket, all torqued up to 45Nm (in easy stages) - aaaand the Allen Stud stripped!! I think I see my mistake, had the Allen Stud been a standard stud with a nut, then on tightening a lot of the stress would have been lateral but with the Allen it would have been all turning stress.

Question is, can a helicoil be fitted in situ without the effort of removing the cylinder head ?? Or any other suggestions

Thanks in anticipation

[DVandrews]

A helicoil can be fitted but it isn't easy with the close proximity of the water rail and the chassis cross member.

It is probably best to remove the water rail, exhaust header and if you have a removable cross member then take this out to.

Oily

[pheasant]

Thanks so far

The crossmember has not been refitted yet so no probs there, removing the water header is a bit of a pain but not so bad compared to taking the head off.

Are the manifold bolts metric or unf ?? its a '99 superlight

[DVandrews]

The threads are a regular M10 x 1.5, when I repaired one in situ, I screwed a long M10 bolt into another of the threads to help me gauge the angle of the dangle required for tapping the hole as it is tricky to judge, you will gain some clearance if you undo the exhaust side engine mount and jack the engine up a little.

Dave

[pheasant]

Thanks Dave for that info, next weekends job !!