Exhaust Manifold stud broken

Post Fri Oct 06, 2017 9:58 am

|Does anyone know what the thickness of the material around the studs are. As in how close are they to the water jacket. Will a m12 thread with an m8 thread insert be ok.?

Post Fri Oct 06, 2017 2:59 pm

well they often get helicoiled - which needs a larger tapped hole to fit the insert

why the jump from m8 - to m12?

Post Fri Oct 06, 2017 3:20 pm

With an internal thread of M8 x 1.25 the drill size is 8.3mm for helicoiling.

Mart.

Post Fri Oct 06, 2017 3:32 pm

less than i thought, but after tapping its in essence like tapping a standard m9/m10 hole

Post Fri Oct 06, 2017 4:32 pm

When a garage repaired a broken stud on my NO.1 cyl., they ended up with a timesert screwed into a larger timesert so there must be a fair bit of metal around them?

Post Sat Oct 07, 2017 5:38 pm

jimmyspeed wrote:less than i thought, but after tapping its in essence like tapping a standard m9/m10 hole

It is indeed but the only other option is to circular mill the hole and weld an insert in which will not be cheep.

Mart.