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Discussion Starter #1
Does anyone know what the dimensions of the lobes on a standard 2600 spider/sprint camshaft should be? I would like to check mine before they go back on to see how worn they are. How much wear can be accommodated by bigger shims before the camshafts are considered to be too worn?

I looked at the Alfa spec sheet attached but it doesn't really leave me any the wiser.

Is "linear displacement of the cup" the difference between the short axis + gap and the long axis on the cam lobe?

For linear displacement of inlet cup do Alfa mean 15mm = 0.590" or ".15mm = 0.00590"

.15mm does not equal 0.590"

Other conversion factors seem a bit all over the place. Maybe it's me.

Thanks.
 

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Good grief! Six of the eight conversions to inch sizes in that table are wrong. .15mm is .0059 inch and .25mm is .0098 inch.
Larry
 

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Richard Jemison
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Wear

Forget finding such data. Measure the lobe heights from BC to nose on both sides of each lobe. If you find differences between lobes and on individual lobes side to side (and you will) it will reflect the wear on the cam`s lobes. And they will be worn.
Total lobe lift (overall height of lobe base to nose, less the BC width) is .354(9.0mm)
 

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Discussion Starter #4
Thanks - since you say that differences will be found, what's the allowance for wear before the camshafts are considered to be dud?

i Different readings between lobes
ii Different reading across a single lobe.
 

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Richard Jemison
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Wear

When both camshaft and cam followers have noticable wear then they are cores only. Worn camshafts will wear out new cam followers fast.. They are only cast with a surface treatment. Not a hard alloy as modern hard welded rebuilds.

Cams from Alfa have a typical life of less than 75,000 miles regardless of lubricants used. Less if thinner oils involved.
 
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