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1913-1914 Holley 4450 "2 Screw" Carburetor Assembly

Posted: Thu Oct 19, 2023 8:05 pm
by VowellArt
In Bruce's Encyclopedia, he lists this carburetor as 1912-1914 Holley 4450 (2 screw), but in the page directly preceding this assembly, he shows Fords 1912 Holley 4450 (which is also a 2 screw) carburetor, but with the body that from the pictures I've been sent is identified as the H1(which I'm also currently drawing). But since the parts are completely different from each other (with the exception of the bowl nut, the drain cock, the bowl nut gasket washer on those pages, I'm calling this one (which I believe to be a later version) a 1913-1914 4450 (2 Screw) Assembly.

1913Holley-4450-2-Screw.jpg

The other problem I'm having is that there is no part number for the bowl nut gasket washer, nor for the bowl gasket or staples for mounting the Choke and Throttle plates to their shafts, which leads me to believe that they're the same as on the later carburetors, but since I can't really say for sure if this is so, I can't put P/N's on any of these parts....now they may be the same as on the earlier version (H1), so if anybody knows for sure this is so, I can put those part numbers on the drawing (or even better), if they're the same as being sold through the vendors now for these parts, then I can use the current P/N's instead.

The earlier 1912 version, looks an awful lot like the "G's" insides, with a separate low speed tube that is mounted through a nipple on the inside of the venturi. The question is, why did they go back to this early form of venturi and low speed parts for the "G" instead of sticking with the their 1913-1914 configuration....answer...I don't know....OORRRR did Bruce get it wrong and what I'm taking as an early version of the 4450, is really the later version? Holly's numbering system is sort of screwy, instead of working in a normal ascending number order, Holly's are all over the map, with 4500 1910 and 6200 in 1921 (and some parts from the 4450 series are even used in the 6200 model in 1921)....fun never quits with Model T. :lol:

Re: 1913-1914 Holley 4450 "2 Screw" Carburetor Assembly

Posted: Fri Oct 20, 2023 9:24 pm
by Corey Walker
The staples that hold the plates on the 4450 2-screw carburetor are the same as the later carburetors. The bowl nut gasket is the same as the earlier H1 and the later G. The top bowl gasket is specific to that model.
That earlier 2 screw is the first version of the H1. I don’t know why they would go back to the previous design with the G. The pot metal venturis were probably cheaper than the spun brass of the 2 screw, then the mixing chamber cover had to fit perfectly so the idle passage would line up in addition to the idle pickup tube having to be soldered to the mixing chamber cover.

Re: 1913-1914 Holley 4450 "2 Screw" Carburetor Assembly

Posted: Sat Oct 21, 2023 7:25 am
by VowellArt
The corrections.

1913-1914Holley-4450-2-Screw-B.jpg

Corey, do you think that the Holley G's gasket set would fit the 2 screw? Just wondering, if I should include that P/N or not.

Re: 1913-1914 Holley 4450 "2 Screw" Carburetor Assembly

Posted: Sat Oct 21, 2023 6:22 pm
by Corey Walker
I get the gaskets from Snyder’s. Only the bowl nut gasket fits from the G.