26-06-2022, 10:19 AM
Although a different head, a finned Cambridge for me, I've had the same problem getting protruding plugs (the right hand ones in your picture) not to be closed up by the valves. My solution was to selectively fit the plugs to cylinders such that the earth electrode, on tightening, sits east/west across the engine in the space between the valve heads. Hacksaw a slot in the HT connector of the plug in line with the earth electrode and selectively fit them such that it then sits across the engine and use additional sealing washers to adjust where it goes 'tight' in the thread. You have to mark each plus so they always go back into the same cylinder. Make sure you fit the plugs with the valves in or near the shut position.
I hope that helps, Dave
I hope that helps, Dave