My curiosity is up. What do you want to look at inside the engine bore?

If all you need is a light to drop down through the spark plug hole
to look at the bore, mine is an instrument light bulb soldered to two
solid core 22 ga. wires, clipped to the battery.
Caution: do NOT rotate the cylinder while light is down the hole.

If you need a surgical quality tv receptor/scope like they put
up your butt, for instance, good luck on finding one. We can
however, make one from some VCR/TV stuff.........

So what do you need to look at?-Bob