gvnick

I've been a little single plane curious, my current combination is running great on an edelbrock dual plane.

The port shape of the Holley manifolds do not follow the cathedral port shape, they are rectangular. What is the reasoning for this? The port in the manifold appears to be smaller than the head port. Science or just cheap China parts?

G Atsma

The "peak" of the cathedral port in the head is where the injector squirts the fuel. Look at a stock manifold. The injector is above the port. That is why cathedral ports are shaped as they are.

gvnick

Thank you, I never owned a stock manifold but just looked at some pics, you're right. Edelbrock obviously bothers to port match the whole cathedral. I'd guess the efi setup is maybe taking advantage of this turbulence with placement of the injector, where on a carb setup it may not be ideal.. Just thoughts.