The first thing you do is fund the air to gas mix ratio.. not to mention hydroxy is already oxygen rich. then you know how to set your hydroxy and air ratio if it can be set due to it being rich of oxygen already...
Then you go here to learn how to caclulate the area of a cylinder
http://www.ehow.com/how_2040922_calcula ... inder.html
Example, a 2 inch piston in diameter is 5.08 Cm in diameter. say the piston can travel 3 inches or 7.62 cm
travel
7.62 cm * pi,, 7.62 * 3.14 = 23.9268
use the diameter to find the radius,, 5.08 / 2 = 2.54 the radius.
2.54*2.54 = 6.4515
23.9268 * 6.4515 = 154.3637502 CC's
so the cylinder needs 154 CC's of something PER Cycle. You should now have the mix, so give that to the cylinder to total 154 cc's.
if its a 4 banger, than you need 154 * 4 = 616 CC's a sec or close to it. this example was based on an very small imaginary motor.