The development of cylinder heads, intake systems, valves, turbochargers, superchargers, or any device or component in an internal combustion engine that has air or liquid or a combination of both flowing through them is a never ending quest for increased efficiency.
In their efforts to engineer and develop optimum performing components, and specifically cylinder heads that deliver more torque or horsepower, engine builders, head designers and manufacturers have long employed and relied upon a “dry” flow bench as their primary testing device to quantify how much or how efficiently their newly designed or modified heads or intake system flows air or an air/fuel mix.
Recently, progressive cylinder head and intake research and development engineers have added a variant of their faithful dry flow bench. Many, the folks at Dart Cylinder head and Reher-Morrison among them, have been testing with a “wet” flow bench.
It is not a new idea. Designers have long used flow benches that used liquid as the medium in the development of fuel pumps, oil pumps, carburetors and other related components. Over ten years ago I saw a wet flow bench being used at C&S Carburetors in St. Louis. I believe that both the Holley and Carter companies have had wet benches and
I’d bet that GM, Ford and Chrysler have long used them, too. But for the most part, a wet flow bench hasn’t been common to many specialty cylinder head shops. The standard has been the dry bench that gives the operator data on the volume of air their products could flow in a finite amount of time and pressure.
For the deep-thinking head porters and intake manifold builders, just having dry airflow numbers wasn’t enough, they wanted visual information that would tell them more about when and where fuel that had been atomized would “fall” or “shear” and revert into liquid instead of being atomized in the combustion chamber. In order to visually experience that moment, some of the engineers used Dyekim, which they sprayed into the flow bench air upstream of the cylinder head. Doing that helped, but it required that the cylinder head or intake surfaces had to be cleaned after each test. They needed a system that would better simulate the actual fuel/air mixture flowing through a cylinder head or intake manifold.
