[Walt Fricke]

Harbor Freight has one which will do the job. Somewhere between $150 and $200 as I recall. Has a 10 or 12mm head (so it will go into spark plug hole). Has a 90 degree mirror you can attach on the end so you can look sideways. Has a small but large enough screen for viewing. Has a button to allow you to capture images. Port for an SD card to store these on and transfer to your computer. And a USB port, which (I forget) either connects directly to computer, or should allow you to view in real time on the computer's screen - I couldn't quite get this part to work. They have one for under $100 also, but its head is too large for the plug hole. The E-Bay one looks like that is the case with it also. You need a semi-rigid stalk for these, not something as flexible as that coiled cord.