You can raise the cranking compression figure by just closing the intake valve very early - like right after BDC.
Example, using my estimating .xls: a 235 with 7.5:1 static CR and IVC at 48° (stock 244° cam) yields about 6.7:1 DCR and 129 psi gauge pressure. Closing the intake at 20° instead brings the gauge up to 147 psi and 7.4:1 DCR.
Why not do this?
Because it kills peak power. Inertia fill ABDC is a big part of the charge mass, as well as a major portion of the total intake event (time in degrees × average lift).
The theory is that if the rate of lift is fast enough, you'll still have good flow during the actual intake cycle (BDC > TDC) but in practice it's not enough.
