Engine guys; how to inspect a cam???

[flyboy1963]

So I need to inspect the cam in my 0-320, FP, has anyone done the 'thru the nose' method, and what are the issues with pulling the plug, and sticking a scope thru the crank, as some guys seem to do?
can you only see the front lobes for cyl #1? The typical Lyc. cut-away leaves me scratching my head.
I prefer NOT to pull a jug, or two.

[C-FAH Q]

To get a look at all the cam lobes and follower faces, you need to pull some jugs. No other way around it.

[flyboy1963]

ok Gary, that makes sense, if you gotta see 'em all!

....but can you see the front one or two? If they were pristine, I would take the odds that all were in reasonably good shape. if one was pitted, then would do further investigation of all.

[C-FAH Q]

Just seeing some of them means nothing. I have seen where all but one is perfect, the last one was garbage.

[Larco]

On my one hand I have 4 1/2 fingers. If you only look at one of my fingers you might assume that I have 5 :-)))) so there you have it.
The point is, if you want to INSPECT the camshaft, pull a cylinder and look at the entire camshaft. You be glad you did regardless what you see. Larry

[flyingriki]

Originally Posted by C-FAH Q

Just seeing some of them means nothing. I have seen where all but one is perfect, the last one was garbage.

Seriously? How 'bout some specifics?

[Marc Bourget]

Gentle reminder, for the forgetful and inexperienced

The jug pulling technique is pull the piston out of the cylinder ONLY enough to expose the piston pin and pull the pin, leaving the piston in the cylinder.

Saves a hone@
!

mjb

[Larco]

Originally Posted by C-FAH Q

Just seeing some of them means nothing. I have seen where all but one is perfect, the last one was garbage.

Me too. Larry

[birddog486]

So I can quickly think of a couple reasons you would want to inspect the cam. The first being the engine has sat for an extended amount of time and your concerned that the cam has rusted. Or, you've found metal in the filter and think it's possibly from the cam.

If you've found metal the first thing you can try is put a dial indicator on the rocker arms which will show you how much lift the cam lobes have. If you find one or more that aren't comparable then it's time to dig deeper.

My O-320 had one bad lobe on the cam that was almost half gone and all others were like new

[C-FAH Q]

Originally Posted by flyingriki

Seriously? How 'bout some specifics?

Ya, seriously, why would I make that up? The last follower was worn so badly there was a grove in the face from what was left of the cam lobe. All the other lobes and followers were in perfect condition. This was on an IO-540.