Airbox to carb intakes ???????????

[sharky]

http://www.asfphotos.com/upload/1267799240.jpg

The 2-1 set-up would keep the tubes the same diameter.
On the other the 2 outer tubes would be squashed slightly oval to clear the frame rails.
I can get ali bends the right size and would be using the original airbox rubbers inside the tubes where they meet the carbs.
Stock airbox rubbers are 100mm long and on the 4 tube design they would be 125mm.
So taking it that everything is sealed up and fits perfectly which would be best ?
My guess is the 4 tube method or would both ideas stuff up the running ?

[DiscoDan]

Option 1 runs the risk of starving cylinder 1 & 4 because you're in a negative pressure (compared to atmospheric) situation. The air is being sucked into the cylinders, rather than forced, so you may well get venturi effect on the openings of 1 & 4 with the way you've drawn them. If you had them doing a more gentle split apart (not 90 degrees as shown) you'd probably be OK.

There's nothing wrong with oval inlets as long as the cross-sectional area is the same, plenty of carbs/injectors do that