[Milepost]

Originally Posted by cgeise

Are you saying the guys working on these dont know what there doing - aand are Not getting there the right way ???????

Consider this Curt.... Most head porters will agree to this statement Chad Speier has on his Home Page....The Flowbench Conspiracy:


"I have had the opportunity to learn from some of the best porters in the industry. Just like grinders, calipers, and even a Sharpie, are tools of our trade, so is a flowbench. In some circles you will find debate that a flowbench isn’t a viable option for developing a port and making power. While I honestly believe it is not the end all, if you know what your looking at and how to apply the data your seeing, it’s a start and good things will happen!

I have also heard the debate that some develop ports without the aid of a flowbench. While this might be true, I wonder what kind of R&D and track expense was encountered in that endeavor? I wonder how many customers are the R&D and don't know it?

I feel with proper use of a pitot tube, and the proper use of some simple math, you can develop a port that will make power and set records. I believe that a flowbench is the lifeblood for a pitot tube. Other devices are of great help. Flow balls, string, even a car antenna! I’m not sure how one can visually look at a area and think that the area is too fast, we need to slow it down. I feel that every means available should be considered in development. If you have flowbench data vs. track results, you can build a data base that will prove successful each and every time.

I also hear that CFM isn’t critical. Well my friends, that’s simply not true! If you have a port that has 2.50 inches of minimum area, and it should move 325 CFM, but only moves 310 CFM, that is a problem! I want the port to flow the proper amount of air for the area available. When you have the proper amount of area needed for your engine combination, each and every time you move more air, it WILL make more power. Now I’m a big believer that the velocity profile vs. the port volume vs. the air moved, is key to a efficient port that will perform as it should. CFM isn’t the first thing to use in choosing a cylinder head, and it’s not tops on the list, but it is critical. WHEN IT COMES TO CYLINDER HEADS, PORT SHAPE, LOCALIZED VELOCITY, AVERAGE VELOCITY AND THEN CFM ARE IN THE ORDER OF IMPORTANCE IN MY DEVELOPMENT.

Now the flowbench itself. Oh boy have I had a battle with this! All I can say is if you own a set of plates and your bench shows it to be off, FIX IT! The equipment is only as good as the operator, and the knowledge of that person. We use a SF600 equipped with a PT Black Box II and Port Flow Analyzer software. Also in the shop is a very powerful, custom all electronic, PTS orifice bench that is used in development to pull higher depressions on the port for further advancements in port shape."