340 intake on a 318?

cudamark said

A big port intake on a small port head is a mismatch in my book. The first factory LA 318 4bbl's started in 1978. By then you had lots of smog equipment, different castings, but still, ports that matched. Mild cams, lean burn, thermoquads, mild compression ratios and cams, restrictive exhausts, etc. Totally different animals. Some combos work fine, some don't.

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Now, I can tell you WHEN it would be an issue. Lets say for instance, we had another application.....one that maybe wasn't even an engine. A large "hole" mated up with a smaller "hole". Lets say air was being pushed under pressure, no negative force from "in front". Then, I could see an issue with turbulence around the perimeter of the smaller opening. Considering the negative pressure surrounding an intake port in an internal combustion engine, I just don't see it as a problem. Although it can be argued (and correctly) that the air and fuel ARE being pushed into the engine, it is because of negative pressure "in front" of that air fuel charge. Were that not present, then I could see an issue.

Help me understand your position on this. It's a good discussion, let's keep it going.