I am looking at building two benches. One that uses all motors in parallel, which will give higher CFM flow for testing exhausts, intake manifolds, and carbs. But I've also thought of building a second bench that uses two banks of motors in series, say 8 motors feeding 8 motors. This should significantly increase the available test pressure.
As you may have read in some of my earlier posts, one bench will have the measurement orifices outside of the bench, by means of ASME code orifice meters in several pipe runs. No chance of leakage this way. But the second bench will be the MSD / Superflow style with the orifice wheel.
The delema that I'm wrestling with at present is how do you minimize leakage on a wheel type orifice bench, when the flow is running in reverse, when doing exhaust work?
For flowing intakes, I see that the differential pressure across the orifice wheel will help to seat that wheel and increase the sealing effectiveness. But my concern is when flow is reversed, and there would be a tendency to partially bow or lift the orifice wheel, and allow flow to exit through the non-active orifices.
The idea that Tony is working with, using the ridgid melamine to mount the orifices would probably reduce this effect, but I just received my 1/8" and 1/4" plates of 24" x 24" 6061 aluminum, and hate to think of cutting them up.
What have people done out there to minimize this kind of leakage when flowing exhaust?
Could this be why the newer Superflow benches look like they use fixed orifices that are accessed through a window on the front of the bench?
Thoughts would be appreciated. Again Tony, you're ideas are great!
Terry