The Squish Velocity Programme enables the user to calculate the peak squish velocity, the crank angle location of the peak squish velocity and the total energy of the squish action for one compression cycle for a two-stroke engine.
This means that it is easy to check the "tune" of an engine and make decisions on if there is scope for further modification of the engine.Top
Suppose you have a two-stroke engine with a 54.0 mm bore, a 54.5 mm stroke and a rod length of 110 mm. The exhaust opens at 83 deg atdc and the peak power speed is 12000 revs/min. The combustion chamber has a squish area of 40% and a squish clearance of 0.85 mm. The trapped compression ratio is 7.8.
Within the engine box enter 54 for the bore, hit the tab key and enter 54.5 for the stroke, hit the tab key and enter 110 for the rod length. Enter the rest of the data and hit the calculate button. The answers are calculated as 26.01 m/s peak squish velocity at a crank angle of 9 deg btdc and the total squish kinetic energy is 3.0mJ. The value that is of most interest to the engine tuner is the peak squish velocity.