Question on port matching

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?


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.

I think I can find one really good video. It’s about turbulence but it’s a really good one. Then I’ll see what else I can find. Some of the best were from the 1950’s and 60’s. Those are a bit tougher to find.

The mismatch doesn’t have to be much if the manifold is smaller. Any change in cross section causes pressure changes in the port. And the Eddie’s that form are quite surprising. Let me see what I can find.