Cylinder Pressure at bottom of power stroke

For a 4-stroke engine - If you have an idea of the pressure and temperature at the end of the intake stroke, and an idea of the exhaust temperature, the absolute pressure at the end of the exhaust stroke is going to be more-or-less in proportion to the ratio of absolute temperatures to the absolute pressure at the end of the intake stroke. The situation is highly dynamic, for obvious reasons, and that pressure ratio is only going to be in the ballpark for the first few degrees of exhaust valve opening (when valve-seat flow matters more than port flow) and won't exist by the time the exhaust valve is opened far enough for the exhaust port flow to matter much relative to the valve-seat flow.

Simulation is widely used for this.

For 2-strokes, dilution during scavenging is going to mean the in-cylinder temperature at time of port opening won't be as connected to exhaust manifold temperature.

I take it, you don't have reference P-V diagrams available? That would be the most informative, assuming the volume at EV opening can be marked. Failing that, BP's input seems quite helpful. However, aside from 2-strokes, scavenging can play quite a role in some 4-strokes also, depending on valve lift curves and port dynamics. Keep an eye on Miller/Atkinson valve timing too, and what that means for "pressure and temperature at the end of the intake stroke".

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

Turbo or NA? It's going to make a big difference.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

Cam timing plays huge in this, as well as other variables. There will be no one size fits all spec.