How To Degree a Camshaft

[EricTheCarGuy]

An essential part of any performance build. You’ll need some special tools, but once you get the hang of it, it’s not that bad.

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[dimitris]

Hey, I’ve got a question on this video.
I don’t understand why did the timing change, by removing the timing chain and refitting it.
Kevin removed the timing chain along with the crankshaft and camshaft gear, but he did not rotate any of the shafts.
Then he rotated the crank gear a few degrees and reinstalled the cam gear and the chain.
So I’m thinking that the relative position/angle of the two shafts remained the same and the timing did not change at all.
What is there that I am missing?

[James P Grosso]

If you watch, after changing the crank gear position, he uses a thin, small screwdriver to move the cam position to align the cam pin with the new can gear location.
I have the same Comp/Powerhouse tools, they make the job fairly easy. The error of the 0.050″ open/closing points is from the dial indicator tools rounded follower. It is not the same as the lifters roller diameter, that is why it is 1-2 degrees off on those open/closing points.
With that dial indicator too, it also comes with a flat face follower for flat tappet camshafts, but it is slightly smaller in diameter than the actual lifter, so it also will have a slight reading error at the open/closing points. These small differences in the tools follower make no difference when measuring the camshaft install center line, because your just measuring the same distance from peak lift on each side of the lobe. He measured 0.050″ before peak lift, and 0.050″ after peak lift. He could have used many different dial indicator values from peak lift, like 0.100″, or 0.150″ lift, as long as the same value is used on each side of peak lift (and you stay away from the opening and closing ramps where the cam will be more asymmetric.) Just saying that the 0.050″ measurement from peak lift should not be confused with the 0.050″ tappet lift numbers from the base circle.

[EricTheCarGuy]

[quote=”demetres” post=180255]Hey, I’ve got a question on this video.
I don’t understand why did the timing change, by removing the timing chain and refitting it.
Kevin removed the timing chain along with the crankshaft and camshaft gear, but he did not rotate any of the shafts.
Then he rotated the crank gear a few degrees and reinstalled the cam gear and the chain.
So I’m thinking that the relative position/angle of the two shafts remained the same and the timing did not change at all.
What is there that I am missing?[/quote]

The different keways in the crank gear allow for 2º adjustments of the timing either advance or retard. Changing to different locations moves the cam gear in relative position to the crank. The crank stayed still, the cam gear moved slightly.

[Author]

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