Petrol leak test

The compressed air test was not very concluant. That's why I took off the head yesterday. Other tests can now be done like the petrol leakage test. It consists in pouring some petrol on the top of the pistons. A faulty ringset will not keep the petrol on top as long as the others. With the pistons at the same height and a stopwatch, you can see what happens and how fast.

Cylinder #3 leaked well ahead of the other three. The pic shows it dry when 2 and 4 were still wet.

The same test can be repeated with the cylinder head by filling the exhaust duct (valves slightly leaking, but not a lot)...

... and the inlet duct (valves completely dry).
A Caterham owner and X/flow expert will tell me what to do next. I guess it means dismantling the bottom end, as already written in an earlier post.
Cheers.