So i'm getting a weird noise in my 350 SBC with camel hump "fuelie" heads. At a constant 3,000 rpm it sounds like there's a steady back fire, an on and off popping sound. A buddy of mine thinks its a floating valve, or on the way to being a floating valve. any opinions?
Have you changed cam or valve springs recently? When i upgraded the springs on my old fuelies the standard pressed in rockers studs started slowly pulling out. If its an exhaust stud pulling out the exhaust valve is not opening as long or efficiently so you will get effectively two compression strokes (well kind of, because the exhaust is not opening enough) so there is still pressure in the cylinder & when the intake opens it will backfire back through the intake. Just my 2c worth.
The Jalopy Journal
