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5.1.7 Performing a Flow Test
For reference purposes, the part being tested
is called the “TEST DEVICE.” The part of the
flowbench where the test device is mounted is
called the “BASEPLATE.”
NOTICE
Test Preliminaries
Remove the test orifice plate from the flowbench and install the test device with any accessories required
(valve opener, radius guide, etc.). Ensure a good seal exists between the test device and the baseplate.
Leak Test
A leak test should be performed to determine if airflow is flowing anywhere besides through the test device.
To do this, you must seal off the normal open port on the test device. On cylinder heads this means the
valves are closed. Other devices may require some sort of cover or block-off plate. If testing in exhaust
mode, make sure the cover is secured or it will be blown off.
Perform the leakage test according to the procedure in section "5.1.6 Setting Leakage" on page 18. Use
the same mode and test pressure that will be used in the normal test.
On flowbench range 1, leakage is usually from 0.5 to 2 cfm (0.50 to 1.0 l/s). If no leakage occurs, the
test flow may read zero. The leakage will not affect the final test results as long as the leakage has been
measured and entered. Entered leakage flow is subtracted from the measured flow for an accurate
measurement.
Flow Test
Remove the cover from the test device, or open the valve in the test head to the first lift point. Set the flow
range to the desired range, see "5.1.4 Setting the Range" on page 17.
Turn ON the motors, see "5.1.5 Turning Motor ON/OFF" on page 18
. Allow the flowbench to stabilize,
and record the readings. Turn the motors OFF.
The flowbench is designed with multiple ranges
so the flow may be measured very accurately. For
greatest accuracy, always test in the lowest range
possible. If over 100% of range, then move up one
range. If less than 70% of range, then move down
at least one range.
NOTICE
Make any changes to the test device as desired and repeat the test.
5.0 Operation
