Hope someone out there can help?
My 427 side oiler has 2 x Holley 4160 carbs and it has recently developed a high pitched whistle sound only at idle and only when the engine is warmed up. I use a homemade engine scope (piece of hose pipe) to locate the source of the noise and found it to be coming from the front carb, left hand secondary venturi. I proved this by hold a piece of clean cloth over the venturi when the engine was running and the whistle sound stopped.
I replaced the base plate gaskets for the correct 4 hole type, and that seemed to solve the problem, until the next time I drove the car the whistle came back!
I have read about the idle and main air bleeds and wonder if they could be the source of the problem.
The engine idles and runs extremely well, no hesitation, crisp throttle response, just this annoying whistle sound at idle. Has anyone else experienced this problem?
Many thanks
Stuart