O-470 camshaft inspection

Rjw872

Does anyone know of a way to inspect a camshaft that is still installed in an O-470. I’ve heard that you can but a borescope down thru the oil fill tube and look or pull a rocker tube and look thru there. Does anyone have any experience or ideas on this. The plane I’m looking at hasn’t flow much over the past few years and I’m concerned about corrosion on the cam.

Scott Sherer

Have you taken it to a shop with appropriate experience?

Paul New

I do this inspection often. Acutally, just did it yesterday while performing a pre-buy evaluation on a P210. Just take the oil filler cap off and put your borescope down through the port. Be careful while rotating the prop to get the crankshaft in a good postition that you don't crush your borescope. You can see one intake cam lobe (the wide one), one exhaust cam lobe and three followers. With a little effort you can look forward and aft to see some of the rest of the cam and lifters but it won't be illuminated well enough to get good quality images. I attached three of the images I tood yesterday so you can see the possibility. No mechanic needed. Just get a borescope and have at it.

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planewrench

NIce shots Paul.

carl

BruceCFVVU

Thanks Paul.

I am going to do this on my 470U during my next oil change when i have my borescope out. I’m not sure what i might find but it may be interesting to do this every oil change to have a benchmark.