@ Spectra
Sir Jee, i remember you were working on making this SYSTEM of changing the flow of Intake air for different settings for CNG and Petrol...
Well, I have made a similar device from watching Exhaust Control Valves on the net. The one I made was to control the amount of exhaust to lower the sound when u are not racing.
Heres a pic of a similar device....except that this one is controled by a mechanical switch, more like the choke switch.. I modified this design to be controlled by a servo.
Now, what is a servo, its a motor which reacts proportionally to the current and voltage provided.
ECV
Servo