i think you'll find to properly understand the noise chrisp's car made at idle with 296's..... go to a building site somewhere in the north of scotland at 4am on a monday morning, in december, chisel enough ice off the cement mixer so that you can turn the starting handle and just as the thing finally coughs into life that "chug/death rattle" noise - that's the noise of chrisp's old engine idling, when warm.
Having had a look at the Schrick website posted by Joe I would susoect that I was right that Schricks quote their cam timing at acctual lift and not from 1mm. Could be wrong but thats how it reads to me. If thats true then it would seem that the standard cams are not as mild as quoted.
The duration is the rotation in degress the valves are held open at a certain lift (VW uses 1mm). If the two cams open at the same point and close at the same point then the duration is the same. The fact the the schrick opens the valve for max lift for longer does not change the duration, this is ramp profile. The cam is possibly the best way to change an engine but like everything it is a compromise between low revs / high torque power to high revs / big bhp power. It depends where abouts you want the torque to be produced. And you cant get the best of both worlds without variable valve timiming, lift and duration.
Thats what I'm getting at. The Schrick will open the valve quicker(not at the same point as a stock cam) and hold the valve open at its upper most for longer. Thats why when using a steeper opening ramp the manufacturer will inturn alter the approach angle(bringing it lower), thus increasing duration.
I'd never do that Seriously, it sounds like the two of them are telling each other the same stuff so I wondered why or what they were discussing.
