Quote:

I'm not really satisfied that event locations (IVC, etc.) are anything more than markers established after the fact, and are faux science as predictors.
The engine cannot see any part of the valve train, including the valve.
What does it see?
Pressure differentials (is the door open or not, and which way is the traffic going - not what the door looks like, or how big it is):
IVO = vacuum begins
IVC = flow reversal point
XVO = residual combustion pressure (balanced against pumping loss)
XVC = after the wave return has peaked

The sole purpose of the position of each event is to anticipate when this pressure change will occur (or reach an acceptable level such as EVO), and if the cam gets it wrong you have no power. Opening the door to no traffic (.800" lift and no vacuum) does nothing. Leaving the door open after traffic starts moving the other way is worse.

A prediction of where X" Hg. will occur in degrees based on a cam card is not going to work, except as a coincidence.



I see a lot of NO NO NO, so tell us some Yes Yes Yes because I am way confused. Especially on your comment that an engine doesn't see the Valves???

From my limited experience you run too small of a valve (small door) or too big (huge Garage door) and your engine will tell you so.

Now when it comes to boost, different story. Bigger is better.

Not trying to say your wrong by no means, just trying to understand your reasoning/theory/way of thinking?