Here’s some diagrams
Usedeconobox, the answer is no, the reliefs in the piston tops do not mean that this is an interference engine. You cannot tell from this photo alone whether the valves would hit the pistons if the cam(s) went out of synch with the crank. Those reliefes may even be sufficient to PREVENT the valves from doing so. The lift of the cam lobes, the duration of the lobes, the design of the head at the cylinder tops, these would need to be known as well to determine of the pistons and valves would hit.
It is, however, a great shot of the top of the water jacket.
Maybe this image will help.
Used Box, you can see from your photo, in this engine, how important and how difficult the head gaskets job is…There is a lot of space between the head bolts…Combustion pressures are tremendous…
Caddy,
I see the 10 round roles for the head bolts (5 and 5)
But, what are the 4 rectangles on the bottom side?
I don’t recognize the block in the photo, but I’d guess they’re oil return passages. After the oil is done lubricating the valvetrain complnents, it simply runs down return passages back to the oil pan.