Quote:
Originally Posted by Tslick  Your talking static compression ratio (bottom dead center).
Gas engines have dynamic compression ratio that is determined by the cam.
In simple terms, depending on the cam lobe, you change the effective length of the stroke by closing the valves and detonate before bottom dead center. |
Quote:
Originally Posted by ///AMG 55
static compression ratio that your engine displays on paper does not translate directly to higher cylinder pressures.... |
Yup, that's exactly what I was referring to - static compression ratio. Which is also the number published by manufacturers as the engines compressin ratio.
But I do understand the point you're both making. Forced induction and NOS also alter dynamic compression ratio/cylinder pressure. NOS in particular generates very high cylinder pressures, giving characteristic very high torque figures, which is why it has such catastrophic failures if not done right. I know when making cam selection on previous cars, I'd read all I could find on the topic - cam profiles is a black art in itself *L*.