19-05-2024, 05:35 PM
Having returned the car to the road yesterday following head gasket failure a week ago (when I was kindly rescued), I am wondering if there might be anything to be learnt from this experience. Most failures are down to 'operator error' and this obviously wasn't an original Austin component but one fitted by me only 3000 miles ago in 2017.
The copper-asbestos type gasket that failed had a smear of orange Hylomar beneath it because the block is a little marked in places (though not near the failure). It was torqued to 18 ft/lbs. The gasket failed between the 2nd and 3rd cylinders - a piece about 3/8" in length had blown out in a direct line between the two exhaust valves. There was no other damage. Significant cooling water had escaped into the oil (mostly after the engine was stopped, I think).
I wondered if that bit of the gasket was running hot - perhaps the cooling isn't all it might be in that area? Or whether the relatively low torque used had contributed to the failure? Or if the layer of Hylomar had contributed? Or a bit of everything.
On assembly this time I used a smear of copper-slip underneath the gasket, and torqued to 18 ft/lbs again. All fine after three runs out.
The copper-asbestos type gasket that failed had a smear of orange Hylomar beneath it because the block is a little marked in places (though not near the failure). It was torqued to 18 ft/lbs. The gasket failed between the 2nd and 3rd cylinders - a piece about 3/8" in length had blown out in a direct line between the two exhaust valves. There was no other damage. Significant cooling water had escaped into the oil (mostly after the engine was stopped, I think).
I wondered if that bit of the gasket was running hot - perhaps the cooling isn't all it might be in that area? Or whether the relatively low torque used had contributed to the failure? Or if the layer of Hylomar had contributed? Or a bit of everything.
On assembly this time I used a smear of copper-slip underneath the gasket, and torqued to 18 ft/lbs again. All fine after three runs out.