SBM Edelbrock/Speedmaster Head Data

Earlie A said

I actually expected plane 6 and plane 1 (on the second row) to react the same as plane 7. I thought the velocity would go to 0 at the seat in all 3 locations. I think it actually does, but I could not get the pitot all the way to the seat. As a matter of fact, at the seat, the flow actually changes directions and is moving up the port at about 170 fps. I measured this with a different pitot in a different test a few weeks ago. I might try that again in the morning.

I may also try taking velocity readings at these same lift points around the guide boss. In this port I have noticed that the guide boss has impacted turbulence/separation more than any other port I have worked on.

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So look at the fps #'s in the middle of the pinch from .550 to .600 and .650...it's slowing down. Actually, backing up! Those speeds (flowing at 28") are WAY too fast. I would really try to get the speed down at the pinch. I know everyone is talking about pinch not a problem, but once you have the port moving or trying to move good air, speeds both local and avg. will make or break the port.
And look at the flow on the floor of the apex, it's slowing down with more lift...very bad! And way way too fast! The port is very out of balance like a crank that's never been balanced...put it on a machine and watch how bad it can be!
One thing I do with eddy heads and SM heads when I'm using a 2.055 valve, looking for 290'ish cfm, is leave the guide boss alone on the front side. It looks ugly, but it stabilizes the air above .550 lift. At least with my porting + valve job + chamber it does. Your dip is coming from way to fast air speed. The valve job + chamber your using may be causing some of this. This is the epoxied chamber/bowl and 50°?