Cam duration @.200" lift

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There is no rule of thumb ...
that @.200" number can change 15 degrees or more for the same duration @.050" depending upon the aggressiveness of the particular lobe profile.

rmcomprandy wrote:There is no rule of thumb ...
that @.200" number can change 15 degrees or more for the same duration @.050" depending upon the aggressiveness of the particular lobe profile.

Agreed. This one reason I tell customers that .050" numbers tell you nothing about the camshaft. It is a reference point selected to "Market" camshafts with. Case in point I have 2 lobes that are .312 and .315 Lobe lift and at .050 they are both 230. Not much difference. Well at .200 there is 14 degrees of difference. One would look at that in .050" numbers and say the one cam is much larger. Well in this case one is much larger. The lobe area is what you need to know. The whole picture.

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This doesn't apply only to roller lobes, it applies to all lobe types.
The 0.200" duration doesn't tell all about a camshaft either.

.006 numbers play too.............

It all matters, but you have to think like an advertiser: what info do we need to sell cams.....needs to be short and sweet. If you put the entire lobe area on there checked at .020" increments you could get 1 lobe per page.

.007" do too.