Isuzu G-series Twin Cam

Just had a G200W head flow tested.

Here are the figures.


valve lift Flow
num thou CFM

Int #1 100 57.5
Int #1 200 112.5
Int #1 300 160
Int #1 400 177
Int #1 450 182

Exh#1 100 51.5
Exh#1 200 102.5
Exh#1 300 131
Exh#1 400 150.5
Exh#1 450 156

The flows were done at 28"
Valve sizes recorded at 1.75" for intake and 1.47" for exhaust