Matt,
I agree that merely having some sort of seat timing in addition to the .053" timing isn't like you cam doctored it [or used a wheel and your brain], but it would still give some idea of the opening and closing ramp designs, in general. I'd like to know what's happening at less than .053" rise and make my own decisions.
Imo, just because they don't supply us with more doesn't mean we should just accept that. Most major car cam companies publish duration at .006" [hyd only] .020", .050" and .200" in their lobe listings. Some will give you more than that if you ask.
Thanks
Dave
p.s. - and what's with the .053" number vs .050"? Anyone know why that became the std? Curious.....
None (that I know of) will give you the actual lobe data files. As far as 'what's happening below .053"?
Not much. That's why they (somewhat) standardized the .050/.053" measurement. (the .003 difference
is almost insignificant imo)
But that still doesn't tell you enough to make any kind of real comparison. You could run Three cams with
identical .053 durations and lifts and get Three completely different sets of results.
It's the
area under the curve that we're mostly interested in. That translates into the valve curtain area that's
presented to the cylinder. Then, there's that area at 'x' degrees of crank rotation. And to further
complicate things, the piston's position (and speed) at that given crank degree (instance).
It gets pretty intense in a hurry. Engine analyzer programs help put some of it in perspective but at
the end of the day (week/month/year), trial and error on a dyno will sort the rest of it out if you're
willing to spend the time.
For 97% of the people, taking what they give you and running it is good enough.