yoshimitsuspeed wrote:oldeskewltoy wrote:
I suspect, can't prove.... that the 33002 may not follow longer duration cams as well as say the HKS, or Toda springs
Also duration is not the issue. In fact a spring will follow a 304 x 8.2mm cam to a higher RPM than it will follow a 264 x 8.2 cam. It is the lift and more importantly the lift to duration ratio. A spring will have more trouble with a 264 x 10.4 turbo cam because it is accelerating open at a higher speed, the mass has more inertia pulling it away from the lobe and then the lobe is dropping away from the spring faster meaning you need more spring to keep it in contact with the lobe.
Just rough guessing if you increased the ratio the same I would guess the max RPM would stay about the same. So if you can spin a 264 x 8.2 spring to 9000 without floating then multiply each by 1.1 and I would expect you could run a 290 x 9 to the same RPM without floating.
The longer the duration the more time the spring has to keep the follower in contact with the lobe and as with most things force / time is what matters.
not to argue... as responding to an aggressive ramp is important... but I'm talking about duration from a total rpm POV.. more duration = more cycles per moment of time.