Exhaust Manifold

Jonn inspected the threads in the cylinder head for the exhaust manifold in our 1963 Fiat 500. The upper thread initially appeared intact, as the bolt tightened correctly. However, the lower hole showed signs of thread damage.

Jonn drilled and tapped the lower hole to fit a helicoil insert. He then cleaned the mating surfaces and refitted the exhaust manifold. The lower bolt now secures properly, but the upper thread has failed and will require a helicoil to be installed next week.