Question on port matching
A sharp edge in the direction of flow is a much better scenario than having a transition to a sharp edge the other way. If the sharp edge is on the head, the air will simply shear off of it and follow the port wall.
If you have the intake smaller where it meets the head, you impose a big low pressure area right there and the air tries to fill in that gap. When it does, it causes eddies and such that kill flow. There are dozens of YouTube videos showing this happening. You never want the intake port smaller than the head.
At what size port mismatch? I understand what your saying. Not arguing it ether. Just wondering at or how much of a mismatch your speaking of. Because earlier you said that a smaller intake runner is bad for power as in choking. While this is a non arguable truth, at what level or size of mismatch. IMO, the way I read it was your saying it’s going to be huge. But what’s the port window differences?
I can’t see a lot with, OH, let’s just call it .010. But I can see a issue with .100. Nevermind some wild intakes I’ve had to mess with that have measure a straight up 1/4 and better! I figure that’s got to be massive even on a low power build. Probably catastrophic on something your looking to make some serious power with.
And that’s another thing. At what power level are you talking about?
It is true. Based on science of fluid dynamics. You can find many videos on YouTube that show this very thing.
Would you mind posting up one or two?
That would be cool to see what’s going on.
I can’t see a minor mismatch being a big issue on low powered builds. I also don’t see the “Eddie’s” in my head unless the mismatch is substantial. Though I don’t know what that particular measurement would be. I can also see that as a percentage rather than a clear cut measurement. A .010 mismatch (ether way) is not the same obstruction between a 318 head and a fully ported max wedge head.
When the OP asked this question, there was no build stated (he’s miles away from a build) no parameters, no displacement given, no goal, just a general question.
