Valve spring limitations vs Cam selection

IN the past, I have used the .005" or .006" lift angles, which in most cases are the angles that fall out of the advertised duration for a hydraulic cam, to get accurate results. And when I say accurate, the cranking compression comes out within 3-4% of the predicted value. So the seat timing is not of value, that I have found.

So for a hydrualic, I use a program where I can plug in the advertised durations, the LSA, and the ICL and it pops out the ICA. It is program by Pat Kelley, and can be downloaded here: Dynamic CR

Or, to compute the ICA based on the advertised duration at .005 to .006", from the typical data for a symmetical lobe cam:

1. Divide the advertised duration by 2
2. Add that to the ICL
3. Subtract 180 to get ICA ABDC

Solids are a different matter, as their advertised numbers are based on very different lift values, and then you have to account for lash.

BTW, from running a lot of these numbers, an ICA of 53 is a pretty small cam if the ramps are the older style, milder ramps. Of course, you have a roller, so that could be a source of things being better. For one with the small an ICA, I would be looking at something like a Voodoo or the Howards. Those will get the valve open more quickly after the initial opening and keep the valve open as much as you can before the valve closing, to get the 'area under the curve' up. I don't usually think of Oregon as a source for cams like that.