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Old 11-23-2018, 06:02 PM
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Tom Vaught Tom Vaught is offline
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Quote:
Originally Posted by Formula jg View Post
Tom, this info is invaluable for us carb die-hards.

Item #10, would you happen to have a pic of a trimmed whistle?
I do not have access to a camera but I do have the dimensions for a Stock White Vent Whistle and the modded White Vent Whistle right in front of me.

Stock White Vent Whistle

Length overall = 2.000" (some may have a slight more or less).

Vent Whistle width is about .6000" (My sample is .605" wide where it fits into the metering block window).

Opening on the end of the whistle (top surface) is .325" from edge of whistle tip and width is .465" length of whistle is

Top to bottom dimension (where it fits into the metering block window) =.225"


Modified White Vent Whistle

Length overall = 1.600" (You can go as short as 1.25" on a pure drag car but a street/ strip car can get by with 1.6" just fine)
It has to do with how hard the fuel slams into the back wall. A car that does a lot of braking would like the longer length.

Vent Whistle width is same .6000" (My sample is .605" wide where it fits into the metering block window).

Opening on the end of the whistle is still .325" from edge of whistle tip which is now 1.600" and width is still .465" (I leave the .030" thick vertical walls on the sides of the opening).
I duplicate the stock opening design).

Top to bottom dimension (where it fits into the metering block window) =.225" as I do not modify the metering block whistle end except to drill the rivit hole in the new part if one is not drilled. A stock white whistle will have the original whistle rivit and hole already there.
The rivit is on the top edge of the metering block.

I am basically cutting .400" off the whistle to do two things:

Gain more clearance for the fuel to hit the back wall, turn, and fall back into the fuel bowl vs splash into the whistle and cause a stumble.

If I just cut .400" off the end of the whistle the vent opening would be very small (as the height does not change of the end of the vent top opening but you would lose .325" of entry area on the top side of the whistle like a stock whistle has.

So simple cut the whistle to look like the stock one in the picture attached but make it .400" shorter in length.

Tom V.
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Last edited by Tom Vaught; 11-23-2018 at 06:07 PM.