Free tools
Induction volume 4-valve
The port volume on a 4-valve head is the average cross-sectional area times the port length. Enter the average port area and port length, and you get the volume in cc. Feel free to add the runner length and plenum area for runner and total induction volume.
All tools
Port volume
112,3 cc
The port volume is the mean area times the port's centreline length. Enter the runner length and plenum area to also get the runner and total induction volume.
How the calculation works
The port volume is the average cross-sectional area times the port's centreline length. With the area in square millimetres and the length in millimetres you get cubic millimetres, which is divided by 1000 for cc. That gives the swept volume in the port.
If you also enter the runner length and plenum area, we work out the runner volume from the mean area of port and plenum over the runner length, and sum it into a total induction volume. The volume affects transient response and, together with the length, which rpm the intake is tuned for. The figures are geometric; real flow is measured on a flow bench.
Example
With an average port area of 1248 mm² and a 90 mm port length the port volume is about 112 cc. Add a 120 mm runner and 2000 mm² plenum area and the runner volume becomes about 195 cc and the total induction volume about 307 cc.
Guide values for port areas on a 4-valve head
| Station | Share of the throat area |
|---|---|
| Port mouth (entry) | 110-115% |
| Divider wall (divider) | 90-95% |
| Longer runner | lower tuning rpm |
| Shorter runner | higher tuning rpm |
Guiding shares. The plenum area is entered directly as an area, not as a shape.
More tools
Related services
Building for real? We take care of the job.
Common questions about induction volume 4-valve
Need help with your engine build?
Describe your project and we will get back to you within 24 hours. Quote after inspection.