Intake Manifold Testing

I’ve been working on a new adapter so that I can flow test intake manifolds.  My hope is to mess around some with porting the intake manifold and not hurt the performance of the part during the learning process.  The new adapter is not quite finished, there’s a little bit of air leakage around the base that should be taken care of with a gasket.

Intake manifold adapter
Intake manifold flowbench adapter


I wanted to try and measure ‘something’ and just measuring the pressure loss through the entire manifold seemed like a boring test at this stage, especially since the leakage at the base would throw the results off slightly.  While running some air through the manifold I thought that it felt as though the air pressure coming from the runner to cylinder 4 was weaker than the runners for cylinder 5 and 6 so I hooked up the velocity probe to measure the air velocity at the manifold runner outlet.

Velocity probe
Velocity probe placed in manifold outlet


The velocity probe is a pitot-static system that will measure the pressure at the probe end and feed the pressures, static and dynamic, to the digital manometer so that the pressure can be recorded or the readings can be converted to an airspeed.  The airspeed reading at the outlet for each runner are shown below.

Intake maniold air velocity readings
Intake manifold air velocity readings (FPS)

Interesting results.