jimbo, cheers for the inlet sizes.
inlet=30mm
exhaust=28.5mm
valve seat angles=90degrees both inlet and exhaust.
In theory, the F7P engine, with money not an option and extensive mods to everything, the engine can produce:
max power = 30 x 30 x 3.1416/4 x 8 = 5654.88
max power = 5654.88 x 1.25 = 7068.6/30 = 235.62
max power = 235.62 BHP MAX!
Also, the inlet valves only need 7.5mm of lift to attain their max airflow, so any cam exceeding that amount, will only make it easier.....
And the inlet ports, to achieve respectable flow and airspeed, ahve to be no less than 75% of the diameter of the inlet valves. Or 22.5mm in diameter.
Just thought it would be cool to work it out.
Of course with enough money to make different crank throws and strokes, re-seat the valves at a different angle to increse the size more is possible. On average, inlet valves can be increased by 7%, so max power with larger valves is:
30 x 1.07 = 32.1mm
max power = 32.1 x 32.1 x 3.1416/4 x 8 = 6474.3
maxpower = 6474.3 x 1.25 = 8092.8/30 = 269.76
max power = 269.76 BHP
If this max power is achieved at say 6750rpm then max torque will be:
torque = 269.76 x 5252/6750
torque = 209ft/lbs
5252 is the rpm where all engines torque and horsepower lines will pass on a dynograph. Assuming that they are on the same axis. If you reading shows that the power and torque curvs cross at any other rpm, its wrong!
Not to be relied on, just a rough guide.