| Home Up | Typical | Set a numeric value or adjust | Engine | Results |
| Bore in mm | 42 - 100 mm | |||
| Stroke in mm | 40 - 66 mm | |||
| Exhaust port open ATDC degrees | 80 - 90 degrees | |||
| Squish size area to bore as % | 40 - 60 percent | |||
| Squish clearance piston to head mm | 1.0 - 3.0 mm | |||
| TDC Traped Compression Ratio | 6.0 - 8.0 | |||
| Conrod length in mm | 100 - 150 mm | |||
| Target RPM | 4000 - 12000 | |||
Area below will hold a velocity plot for gas trapped as piston rises above exhaust port to squish head
Target squish gas jet speed is 18 - 25 metres/second with 22 - 25 using best racing fuel
Note that the ignition is often about 18-20 BTDC and well underway by the time the jet hits it - dont blow it out!
And finally the simulation here is for cold motor cranking