Boroscope

[dmac]

Here is a relatively inexpensive boroscope - handy for looking inside cylinders to check for scoring and such. boroscope

[ChrisBennet]

I have one of those and I haven't found it that useful. The resolution is just not too good and it doesn't look sideways i.e. look down a plug hole and you can't see anything but the piston.
-Chris

[dmac]

So you can't bend it around easily to check the cylinder walls? I don't own one.

[ChrisBennet]

Originally posted by dmac
So you can't bend it around easily to check the cylinder walls? I don't own one.

You could probable see some wall but not near the top of the cylinder. It doesn't bend very sharply and says to avoid doing so.
You can see valve marks on the top of a piston with it and look at the oil pressure switch on the back of a motor.
-Chris