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Check cam without pulling cylinder?

YES you can inspect the front lobes. I have a Vivida ?? (stick one)and have a motor was supposed to only have 4.2 hours on it that has been sitting for 25 years in warm areas, so wanted to have a look see. I bought the $500.00 smaller ended flexible Vivita so's I could look up the factory crack in the case after you pull the pan off
WELL guess what??? the stick Vivida went up through the crack and my cam looks great. The crack is big enough.
Now if you have a problem with the rear cylinder cam lobes, it's cylinder pulling time.
Sure wish I had tried the cheap one before I bought the spendy one
My luck varies Art
 
Maybe it's just me, but it's difficult to asess the condtion of the cam without wiping off oil and shining a bright light at it. It's even worse for the tappets: they are pressed against the cam by the rocker springs and most of their surface is hidden.
 
Not sure which engine you are asking about. I can say for certain that the accessory end (rear half) of an early O-360-A1A can be accessed with the sump off. It requires a very small diameter camera. I used both an articulating borescope camera and a flexible camera. You have to work up thru the thin oil drain slots or the triangle shaped opening (on the back, under the crank) and work your way around the crank. It is not easy or ideal.

20230418_165036-777x1024.jpg


I've heard that with some engine (a six cylinder??), going thru the oil filler works. As you can see from the above photo, that would be really difficult on an O-360 as you would need to make a 150 degree(??) turn to go up one of those thin oil drain slits and then still have to work your way around the crankshaft.

As isosceles noted, what you see may require some interpretation and/or an experienced eye. I looked at one and was certain the cam was shot - it turned out to be fine.
 
Yep, it's more about knowing what a good or bad cam actually looks like. When bore scoping turbines you usually have a few photographs of good/bad examples to reference. Doing the inspections at repair stations require a additional rating/school.
 
newt said:
Depending on your engine's configuration, you might be able to go in through the crankshaft bore through the propeller flange.

https://vansairforce.net/community/showthread.php?t=198567

Second page of the thread has a diagram that shows what's going on.

- mark
Click to expand...

Great tip!

If you go this way and if it's fixed pitch with the hollow crank, may as well knock out SB505 while you're in there

If you're wondering what NOT to find...here's is my recent discovery...
 

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