18-12-2020, 01:47 PM
That looks like oil to me, not water which suggests that your engine is worn, allowing oil past the piston rings into the combustion chambers, hence the carbon build up. It is a phenomenon exacerbated by the late 37 head design which places the spark plug right on the circumference of the bore and directly in line with any oil coming up from below.
Turn the engine over by hand and see if there is any movement of the piston relative to the bore when at the top of its stroke (repeat for all 4). If there is, then you're probably needing a rebore and a set of pistons.
Clean up the top surface of the pistons to see what size they are.
Turn the engine over by hand and see if there is any movement of the piston relative to the bore when at the top of its stroke (repeat for all 4). If there is, then you're probably needing a rebore and a set of pistons.
Clean up the top surface of the pistons to see what size they are.