These are some of the kinds of images of
valves that can be captured with a "dental" inspection camera to assist you in evaluating the
condition of your valve faces and seats. See the entire
BeechTalk thread on this
HERE. Images below also courtesy of BeechTalker Joe Fischetti.
This might be a good tool to suggest to your
mechanic or if you are inclined to have one for your own use, I've not seen
anything do such a great job for such a CSOB cost.
Joe advises that for better access into the
spark plug hole the shaft of the camera needs to be modified or ground down a
little. Here is how John W. tackled the problem. Ending up with heat shrink on
his end product:
Nice job Joe!
NEWS FLASH March 4th, 2014: The below
camera has gotten great pireps from Beech owners and it is now priced at $52!
Here's Jim S.'s 12/21/2013 pirep on the camera
It works great, and is more than adequate for the job.
It plugged into my Mac over USB. The Mac Photo Booth app recognized it
readily, and clicking the red button takes the picture.
Pull all the top plugs, turn the prop until the piston is out of the way and
the exhaust valve is closed. Put the camera in and snap the pic. You get a live
video feed, so you can watch the exhaust valve open and close (provided the
piston isn't in the top 30% of travel) and can readily frame up the picture.
Don't smack the camera with the piston. The camera is plastic and would
probably break before hurting anything, but don't be dumb.
Below are the pics from today's trial. I did #6 first, and I got better at it
on the other 5 cylinders and didn't bother to go re-take #6. All compressions
were good. Lowest was 68; all leakage seemed to be ring leakage.
The camera fits in the spark plug hole as it comes, but it's snug I'm going
to gently file or sand down the corners a bit to make it drag less on the
threads, but it definitely went in right out of the box.
Hope this helps. (BTW, dx.com seems legitimate to me; I've ordered from them
3x and never had a problem with fraud, but my first order with them raised my
"fraud yellow alert" spidey-sense.)
Here's another bore scope inspection camera that
has gotten good pireps from Beech owners. The 5.5mm head makes for an excellent
size to get into the TCM cylinder spark plug hole and it's priced at $160 on