Whistling Power Valves

cannondalerob

cannondalerob

Junior Member
I just puchased some new power valves for my Holley 94 Carbs. They whistle like a screaming banchi. I used the seats that came with the valves. What did I do wrong. The Car runs great. It just sounds like I have a built in wolf whistle!
 
Strange! The top side of the valve (spring end) is immersed in gasoline in the float bowl so unlikely to whistle. The diaphragm side is in a dead end chamber exposed to manifold vacuum so no air flow through here to cause a whistle, either. Could it be a bad gasket between the main body and throttle plate body, or bad base gasket? Do you have vacuum wipers, with a split in the hose?
 
I just went thru this. I rebuilt the carb on an engine on my test stand. Boy, did it whistle. Mentioned it to Walt Dupont and he said to check the gasket between the main body and the throttle plate body. Flat filed the surfaces and put a new gasket on. Whistle gone!!
John
 
Ditto what jwl says. I had the same problem on a model 59 carb . Thin gasket on probably warped body surfaces. Thicker gasket on on leveled surfaces cured the whistling. Vacuum leak enough to cause noise but not enough to effect performance.
 
cannondalerob said:
I just puchased some new power valves for my Holley 94 Carbs. They whistle like a screaming banchi. I used the seats that came with the valves. What did I do wrong. The Car runs great. It just sounds like I have a built in wolf whistle!
Click to expand...
WHAT # PV's did you buy??? You should be using #5.5 ones unless your running a 2x2 setup,then use 4.5 or even 3.5 / 3.5 are pretty hard to find but i stock 4.5 and 5.5. and do NOT use the gasket for them that has a triangle shaped hole,there just garbage.ken ct. PV's will not whistle. You got an air leak between the base and middle section.File both surfaces smooth and use an USA made gasket no China made garbage in there. ken ct.:) What are you calling the seats for the PV [the gasket]???
 
One other thing...some people mistake the spark valve thing on the back of some later 94 variants for a power valve because it looks about the same...that one can cause a vac leak to open air. So...if you are looking at an odd device on the back of the carb, that could actually whistle, but it isn't a power valve.
 
See if you can get them to play "Carnival of Venice," and you'll be a shoo-in for "America Has Talent." :)
 
It's worth the the extra money if you purchase the carb from Uncle Max. He stands behind them 100%. and you wouldn't be whistling Dixie. He took care my carbs and I didn't even buy them from him.
 
Got to agree with the whistle being caused by an air leak between the base and mid section of the 94s. Make sure both mating surfaces are flat. Use a thicker gasket and coat both sides with a little grease. Cured my whistling carbs this way.
 
Interesting that some people say true the mating surfaces=free, and some say buy a new Stromberg=$400??

File the surfaces flat, end of problem.
 
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