K Series Head Exhaust Stud Issue

Was that stud too long and bottomed out? As said there's no meat there, but it might be worth finding out if you can drill and tap a slightly deeper hole there (depending on water jacket oil ways etc).

I'd be drilling deeper and tapping the existing thread size then finding a longer stud.

Ideally have a look to see if you can avoid water jacket etc but even thats not the end of the world as you can fit the stud with threadlock and it will seal. A friend did exactly that after drilling into the waterway.


If you do go down the route of inserting it helicoil isnt the way to go with an open side, something like Time-serts will be more likely to work as they are sold rather than the coiled wire of a helicoil.

As above, weld and timesert is the only way that's gonna fix properly. Helicoils are garbage.

I've never heard anyone speak badly of a helicoil before, they're fine - I've used loads of em. The only problem is if it's a thread that's used regularly, sometimes the insert can try and come out with the fastener which is annoying.

No good if you break through into a waterway though as they'll never seal.