Budget 408 Build

rumblefish360 said
Excellent notation.

To all newbies and cam rookies;

Keep in mind that you can call the grinder to adjust the cam your looking at in the book. If it says it has a 110 C-line and you want a 106, call them and ask!

Cams in the Catolog have not changed in there thought pattern in decades. (Grinders thoughts) Then came along fuel injection with the need to widen the C-line to at least 112 with 114 being more helpful for the computers to grasp what is going on.

The aftermarket settled on a 110 for its sound and the normally found stock displacements of factory offerings. It worked well. There was a "No big deal" attitude towards 2*'s adjustment to go up for a 360 or down to a 318. Add 40-50 cubic inches and the better acting cams are no longer shelf cams because the custom grinder that actually knows what is going on can adjust the timing events to suite.

Nothing wrong with a shelf cam. But everything should be better when the cam, custom speced, suites the engine and what it is supposed to do.

One other thing to consider; any cam with more exhaust duration than intake will act like a cam with a narrower LSA because in effect it is, save for the exhaust opening. To figure out how to truly compare cams in this situation, the difference in duration divided by four will give you the true comparison of sorts. Example; my mother thumpr cam is 235 int 249 ex. 107 lsa. But it has 14 degrees more exhaust duration. 14 / 4 = 3.5, So the overlap is the same as a cam cut on 103.5. No wonder they have a rough idle! One source of info on what really works for a 350 inch size motor is to look at Mopars cam offerings for circle track racing. They are all cut on narrow LSAs, even the smallest short track cams. They don't give a hoot about idle quality, it is all about torque coming off the corner.
OP, hope you don't mind the hijack! It builds your case for a custom cam though, because every engine size wants its' own lsa. Now back to the regularly scheduled program!