Direct Connection ( Mullen LA ) heads
That is the type of info that is helpful!
Thanks.
I still maintain that I put a disclaimer on my numbers when I posted them. Evidently others didn't realize that or chose not to.
I plainly stated my homemade bench..
Again, thanks.
We all get that. The issue is guys like PRH and the rest can’t make sense of what your are doing if your numbers don’t equate to standard science. I mean, if you think about it, you could measure your air flow in some made up standard...like buckets of air per minute. The you'd need to determine how big the bucket is, and at what test pressure you are filling said bucket at. Then you’d need to be able to scale your buckets per minute (BPM for short) to CFM so you can determine, understand and quantify if what you are doing is actually working or if you are just making numbers.
I have never been, nor will I be convinced that a correctly operated flow bench will read more than 1% (in practice I know it’s that much at most) difference between them.
If you are using a calibration plate and if you use correction software (you should be using both) any flow bench, anywhere in the country will read the same, with the exception of crooks and liars, of which there are many.
To steepen your learning curve you should be working to get your bench calibrated and get some software to correct for temperature and barometer. You can take the same exact port and flow it in early spring or late fall where I live and get her numbers. Do it again in the dog days of summer and that same port will be sucking buttermilk. You have to correct for that and use the corrected numbers or small weather changes will skew the results.
It’s not a slam on you or being critical of your work. They are trying to help you (for free I might add and what they are telling you is big $$$$ if you had to pay for it) to be a better head porter and to be able to do that, they need numbers based in science and not just arbitrary stuff.
BTW, the only advice I can offer is never port the exhaust using the numbers. If you do that, you’ll kill power every time. The flow bench will lie to you and tell you to make the port bigger and bigger and then it will reward you with big flow numbers. But although they look good and the numbers are big, that exhaust port will kill power so fast your head will fall off.
Get the port as small and as quiet as you can and screw the flow numbers. Flow the ports in reverse and see what they do. Experiment. Just use numbers that are relatable and the guys here will help you learn more, faster.
