10-02-2018, 09:53 PM
To provide a good watertight seal (practical if non original), I countersink the hole in the top of the casting with a 45 degree cutter, just deep enough to accommodate
the volume of an 'O' ring of the same i/d as the unthreaded portion of the stud and screw down the nut (or setbolt head) to squish the'O' ring into the cavity. A better engineering solution would be to counterbore the cavity just deep enough for the volume of the 'o' ring to squish up fully within the counterbore space. I suspect though that most of us have access to countersinks...............
Fit a plain steel or fibre washer between nut and 'O' ring and the job's perfect for thousands of miles - it's the rubber/cork gasket against the block or head face that's more likely to give out. I've done several engines like this and I've still got friends!
Life would have been so much easier if 'O' rings had been readily available all those years ago!
Hope this helps
Cheers
Bob
the volume of an 'O' ring of the same i/d as the unthreaded portion of the stud and screw down the nut (or setbolt head) to squish the'O' ring into the cavity. A better engineering solution would be to counterbore the cavity just deep enough for the volume of the 'o' ring to squish up fully within the counterbore space. I suspect though that most of us have access to countersinks...............
Fit a plain steel or fibre washer between nut and 'O' ring and the job's perfect for thousands of miles - it's the rubber/cork gasket against the block or head face that's more likely to give out. I've done several engines like this and I've still got friends!
Life would have been so much easier if 'O' rings had been readily available all those years ago!
Hope this helps
Cheers
Bob