I read today that testing at 28" a low flow was better but that keeping it the same at higher lifts as the pressure drops and not re adjusting to 28" was a more realistic of what happens under normal driving conditions
Does anyone test this way of the forum
This is just the same old David Vizard concept of floating depression, there is much heated discussion on it just search his name and yeas people do flow this way but no one i know .
My suggestion is to build a flowbench if you do not have one, flow the heads based on whatever theory you choose then Dyno the motor and see what happens, my theory says that after a few iterations you will not use just one flow method and in the end you will be more concerned with "Velocity Profiles" than actual flow numbers.
yes i believe floating depression was the term used..
yes i understand the need to get the flow bench up and running but dont have funds as yet. just trying to read what i can and hopefully limit mistake's once i do have funds.
thats why i posted to get some real time knowledge from people that do have their benches running and real world experience. thanks for all your replys
I think it is always worth while to do as much research and learning as possible, but my thoughts about the flowbench are pretty strict, there is so much proven data on testing at 28" historically that it is worth starting there to create a strong foundation of comparative knowledge to others testing. Once your porting skills reach a point that you think you can do more "Velocity profiles become the focus", once you have a strong grasp on that and your porting skill follow then off to testing at 36" or 60" and comparing data both flow and velocity as they can easily be scaled up or down to validate your changes both good and bad.
Remember the flowbench is only one tool in the box needed to prove your work was a gain or a loss, the Dyno, Et, 60 Ft, Lap times all are the real proof.
Good luck in your research and don't be afraid to ask those questions as they keep the forum alive.
In my opinion there's really no right or wrong way to flow test. You can do any way you like as many have done but its when you would like to compare numbers to somebody else or sell your product commercially that calibration and a common flow 'standard' is needed.
That's when methods become important.
Me personally I'm way more interested in waving a probe around at a few set depressions than the floating depression rollercoaster or seeing a big peak number @ 28.
1960FL wrote:
Good luck in your research and don't be afraid to ask those questions as they keep the forum alive.
Yes I,m just trying to find a point to start.. useless till i get my bench built.. but would like to try to form a clear understanding of the methods at least..
I want to develop a head for an engine i,m building and though I am understanding the flow side.. the velocity testing and wet testing all seems a little harder to grasp especially as tiny changes can have such a large effect..
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