Hot Rods HELP - Whistling Blown Flathead

Hey Gang, I just bought a killer '40 Ford here on the HAMB with a Weiand blown '48 Merc flathead. I've never owned a flathead V8, or a supercharger, so probably had no business buying this, but it was just too cool not to try the learning curve. It was advertised as a turnkey daily, so first task was to drive it home over 200 miles, which the car did without issue, smooth running mill...not much sound from the supercharger (I expected it to whine a bit). Next day took the car to breakfast, all good. Returned home and when backing into the garage the car started whistling Dixie to high heaven, a sound I've never heard from any car, like a teapot at full boil. See/hear attached video. Is this the supercharger? Gasket leak? I don't even know where to start. Worth noting, after the car cooled down I restarted and the sound disappeared or became super faint, maybe some heat expansion causing a leak? Any wisdom would be greatly appreciated!
Best,
Bill

 

Maybe one of your carb butterflies is open a tad and the blower is sucking air past them at an idle.
I have had a few of those little superchargers and they don't make much noise. Of course, I am also half deaf, so I have to take that into consideration.

 

Did it stop whistling? What was causing it? Inquiring minds want to know!

 

I had a 6L ford 200 that whistled, dry front seal.

 

Spray a little carb cleaner around the carb base. Does it speed up? Might be a leaking base gasket ??

 

Hey y'all! The whistling continues! I tried tightening the intake and carb hold-down bolts to no avail. Covering up the carbs with my hand to constrict airflow does not seem to affect the whistle. One additional phenomenon to note; when the engine is loaded (in gear and driving) the whistling subsides. The whistle is much more prevalent during idle or when the engine is not under load. I was thinking about starting to spray starter fluid or carb cleaner around to see if I can get an increase in RPM such as what @Hotrodmyk suggested...this will be the next step. Thanks for your input!

 

Use a piece of garden hose as a stethoscope and you should be able to find the whistle

 

There's much less vacuum under load than at idle, so that would suggest a leak. Try the carb spray test around anything exposed to vacuum.

 

It sure sounds like a vacuum leak, but it's supercharged, so, I don't know if that would apply...

 

Garden hose Will find it period. Blown or not makes no difference.

 

Certainly sounds like a vacuum leak the pitch changes with the engine RPM . Start spraying around the base area of the blower it could be the gasket between the blower and the intake. Or if there's a PCV valve look at that area as well. Also look at the oil fill area.
If you drive the car and push it hard it may begin to pop in the carbs this is an indication of a lean situation caused by air getting into the intake system somehow.

Welcome to the world of flatheads your getting in really deep right from the beginning let the learning begin.
Ronnieroadster

 

LEAK FOUND! I got really close with a garden hose but not right on it, because the pinhole was hiding right behind the driver's side radiator hose at the intake (to block) gasket...there is also only about 1/8" between the cylinder head and intake at this location, so just a tough spot in general. From talking with Joe Abbin of Roadrunner Engineering (supercharged flathead guru), this intake gasket failing is virtually unheard of.
I was able to pinpoint the leak using distilled water in a turkey baster to precisely drop water around the area. When the water was sucked in the whistle was silenced. This method worked very nicely, very clean and precise. Now to the fix. I might temporarily apply some high temp silicone to the area until I get around to tearing off the blower and intake to replace that gasket. Thanks to all who commented, and especially to Joe Abbin for his wisdom.