Don't understand cams

Not long ago I actually queried Maxwell, a camshaft tech at Comp cams on the process of determining the right camshaft for any given engine combination.

Giving him the two opposing viewpoints as mentioned earlier in this thread as such

"One first of us believes that the camshaft technician Determines which duration and lobe separation figures specifically will be optimal. without looking specifically at valve timing event specifically unless trying to design on the ragged edge of detonation in a competitive racing application.

This person believes that the technician employs his knowledge and experience of the relationships which duration and lobe separation angle both have on an engine's performance in a variety of configurations and applications.

That valve timing events are incidental to duration and lobe separation angle. That Valve timing events are mostly used as a way to check or make sure that the finished camshaft is installed in the correct position relative to the crankshaft.


The second of us believes that instead, the technician will first determine all the optimum valve timing event numbers specifically. That the cam technician employs his knowledge and experience of altering each valve timing event and their relationship with an engine's performance in a variety of configurations and applications. That it is instead duration and lobe separation which are incidental, since they are only selected as a means of achieving the desired timing events.

Which parts did we get right?
Which parts did we get wrong?"

And his response was as follows.

"I can mainly speak about my methodology, which is shared by many at COMP(I was taught by the best). I have been at this for almost 14 years, so I believe I can speak with some experience.

You are both right to an extent. The first guy is more correct for choosing a cam on a fresh engine combination.
Once an engine combination has been run with a specific camshaft, then the second approach can be taken to taylor and improve the performance.

It is pretty difficult to explain to an outsider. The only way to get really good at camshaft design is to work at a camshaft company. After full immersion for 8 hours a day for a number of years, duration and lobe separation angle numbers come to mind automatically. It's kind of like becoming fluent in a second language.

Once, I decide on duration, then I will search for a lobe with the proper amount of lift to accommodate the cylinder head flow, and valve spring package. Also, the aggressiveness of the lobe must taken to account depending on the engine's application. For instance, a softer, smoother lobe must be used for an endurance application. On the other hand, a heads-up drag racing class where every last horsepower counts would require very aggressive profiles.

I hope that helps answer your question."

So there you have it, some expert insight into the process and methodology of determining the correct camshaft for a given application.