20-01-2018, 01:13 PM
Those cheap plastic fuel filters do not work well with gravity feed, sometimes causing starvation. They are designed for pressure systems. My fabric racing special ran for 25 years on a Chummy tank, no pump and a Mini semi-downdraught SU which I converted to semi updraught by inverting the Nippy inlet manifold to increase the gravity-drop. SUs will work in any direction as long as one adjusts the float bowl height.