PTS Flowbench Forum

Hi guys
My build is coming along and I've just ordered motors.
I had a couple of Ametek 119996-00 motors that I bought a few years ago. I just ordered another 6 which I'll pay for tomorrow.

Reading a couple of other posts, should I be looking for flow @around 40" test pressure? The sheet for my motors says 82.9cfm@42.7In.H2O. It also says orifice 1"

Does this mean I should be able to test 640cfm@28" on my flowbench using 8 motors?

Just checking to see I'm getting decent motors.

My second question is, will the bench be usable at low motor speeds with 8 motors spinning slowly. I'll mostly be working on SR20VE cylinder heads

When testing the pressure drop will be 28 inches through what is being tested, plus a nominal 16 inches of further pressure drop through the measurement orifice.
The vacuum motors will then be working against a 44 inch total depression.

The specified 42.7 inches is so close to 44 inches, the difference is not worth worrying about.

As you add more and more motors together in very close proximity, they tend to steal air from each other on the intake side due to induced turbulence. This effect is not serious, but the total flow will be slightly less than 8 x 82.9CFM. Difficult to put an exact figure on it, but something around 640CFM sounds like a very realistic expectation.

Yes you can run all eight motors continuously at low speed without any problem. The drive horsepower increases cubed law with rpm, so at very low motor speeds, the current (and motor heating) will be far less than the available cooling airflow volume. In fact its the best way to do it. Motor life should be increased, and noise will be less running eight motors slowly rather than perhaps only two motors nearly flat out.