Tunnel ram or no tunnel ram...

71GSSDemon said

Thank you and I was fairly confident this was the type of answer I would get and greatly appreciate it. It makes perfect sense for tuning especially during racing. I do have another question though. The front primary bowl is in front of the metering block, fuel pushing back while accelerating would be covering the jets more and the floats then dropping would increase bowl volume during said event....right? It is the rear bowl that would uncover the jets, but in the 4160s there is a metering plate instead. The jet extensions would help more for decelerating in the 4160 whereas the 4150 would need rear jet extensions, i think. Am I confusing this comment " 4. You end up with the little float bowls with side hung floats. There isn’t much you can do with those floats to help with fuel moving to the rear of the bowls. The fuel will stack up at the rear and push the floats up, reducing flow if not shutting the needle and seats off completely.

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One of the things that happens to a fluid when it finds a 90 degree wall is the fluid tries to climb the wall. It also finds its way into the corners. If the corners are close together, say in an oil pan or a float bowl, that fluid will also stack up in the corners.

This is why some oil pans that might look good (think box style pans) are really junk unless they have extensive baffling to keep the oil from standing up in the corners on a hard launch. Too bad the butt heads at Stef’s didn’t know this when they built my pan in 1996. Of course, I didn’t know it either and 3 broken rods later I figured it out.

That same thing happens in a float bowl. Once the fuel slams into the back of the bowl (in reality, the fuel remains stationary in the bowl or oil pan and the float bowl or oil pan runs into it) it starts migrating over to the corners.

So the side hung float can still get lifted by the fuel in the corners.

That’s why it’s nice to have the center hung bowls that hold more volume and you can wedge cut both sides of the float.

It makes it so fuel movement doesn’t affect float drop nearly as much.