My head has been ported, which helps, but the biggest difference was when I removed the air choking secondary throttle plates.
LLoyd
Wherever space and time interact, there is information, and wherever information can be ordered into knowledge, and knowledge can be applied, there is intelligence.
Pavel Mirsky, mid 21st Century Russian General
It is such an easy, and easy to reverse (though never would I think of doing that) modification, that it’s kinda hard to believe, till one experiences it.
John, it is part of the emission manifold on the S2 with Stromberg carbs. Your S1 with SU’s do not have the emission manifold wihich re routes the flow with these second throttle plates.
Tom