How To Find The Cam Centerline
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Joined: Oct 2005
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Find top dead center and zero the degree wheel. Find intake opening @ .050" lifter rise, note the degree before tdc. Find intake closing @ .050" lifter rise, note the degree after bottom dead center. add intake opening + intake closing + 180. Divide by 2 then subtract intake opening. This is your intake centerline.
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Find top dead center and zero the degree wheel. Find intake opening @ .050" lifter rise, note the degree before tdc. Find intake closing @ .050" lifter rise, note the degree after bottom dead center. add intake opening + intake closing + 180. Divide by 2 then subtract intake opening. This is your intake centerline.
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Joined: Dec 2017
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Yes.
That's drastically oversimplified for most modern cams, which do not have symmetrical opening and closing ramps (opening is usually MUCH steeper than closing, esp right near the seat) so it's not real accurate. That is, peak lift is most likely NOT in the "center" as found by that method, and may or may not match the mfr's published specs. Butt it's better than nothing. Finding peak lift with a dial indicator will give you the other half of the picture which again may or may not match how the mfr specs their product.
That's drastically oversimplified for most modern cams, which do not have symmetrical opening and closing ramps (opening is usually MUCH steeper than closing, esp right near the seat) so it's not real accurate. That is, peak lift is most likely NOT in the "center" as found by that method, and may or may not match the mfr's published specs. Butt it's better than nothing. Finding peak lift with a dial indicator will give you the other half of the picture which again may or may not match how the mfr specs their product.
