More in a 5 port head kind of way
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Ahhh yes. Back to the reality of the 5 port BMC cylinder head . . . . . . .Okay, for those of you building BMC's, some real world graphs, and, the corresponding numerical data.
I've posted the graph and descriptions one at a time again so viewers can use their screen zoom function to enlarge the images without jumbling the captions. Once you have an enlarged image, you can use any screen capture method to download/print the information.
This is the graph of Midget's cylinder head flow, all 4 cylinders, both intake and exhaust. Cylinder head flow only, using a radius inlet adaptor and an exhaust pipe stub. Contact me via PM if you want the details on my adaptors. You MUST use some adaptor(s) in your flow testing to obtain consistent and valid results. My retests are typically within .3%. You will notice that one intake port and one exhaust port are each significantly better than the other 3 ports . . . . . . . .
The flow data for the graph above, all cylinders.
This is a graph of Midget's cylinder head, averaged flow, versus some other good flowing heads. Midget's head has very good low-lift and mid-lift flow numbers. All heads were tested using the same intake and exhaust flow adaptors, for consistent results. These are all big valve type, all out race heads. I do have some flow results for heads with smaller (mid-size) valves. If there is enough interest, I can post those numbers as well. At this point in time, I DO NOT have any test results for small valve/small bore heads. If you want one of those types of heads tested, send me a PM.
This is the data for the second graph using average flow values of each cylinder head.
This is data that I've posted before, in a different format. Previously, I did not include the data numbers, so now these can be used to evaluate other cylinder heads being tested by others in differing locations. If you are going to test and do a comparison, try to test @ 28" of test pressure. That is the value I test with, and then there will be NO correction factor for test pressure. Your test results at a different test pressure can be corrected to 28" or you can factor my test results lower. I personally think that it is best to test at the same pressure . . . . . . as you still have any differences in the flow benches to account for . . . . . . .
Flowmonkey