Just put a K&N air filter on my 350 chevy with 750 carb. Now the whisteling noise that I had before is much more noticable. What causes that high pitched noise? It seems to only do it when the secondarys start to open.

Mine did the same after I changed from stock to Weiand Stealth intake. I looked for hours thinking I had a vacume leak. No leak and others have reported the same. One guy had twins and one motor whistled, the other didnt. JUst tell your friends its the turbo spinnin up.

What song is it? The old Mayberry song would be kinda cool.

Ditto on Holley 800 with K&N. Chased belts and vaccum leaks. Seems more pronounced with certain temps and humidity levels. The K&N does not muffle the sound as much as the Purolator filter I was running before. I think it sounds like money getting sucked into the engine!

Tim T.

Does your carb have vac. secondaries on it?.....Fred

Yes, it's got vacume secondarys. The whisteling starts as soon as the secondary throttle blades start to open.

I have had carbs. with vac. secondaries that whistle when the secondaries open and when they close.....anyone else have this experience?....Fred

Its just the air being sucked in the secondaries, put a canfield spacer plate under an 800 holley and it sounded like a sceaming wild animal.

I've got mechanical secondaries and mine whistle. They will usually make noise when I'm about 1200 rpms and go away when I come on a plane. I think it may be the holes drilled in the blades. Maybe the burr on the back side caused by the drill is causing the whistling. I'm running 750 holleys on small blocks. I seems common to holleys. I gave up trying to find out why.

My old jet boat had a 469cu Olds and it scared me the first time the big 850 opened. I guess that is a noise result of the CFM rating.