The Carburetor Shop LLC
204 East 15th Street
Eldon, Missouri 65026
Buick carburetors 1937 and 1938
For 1937, Buick discontinued use of the Stromberg EE-1 carburetor used on the 1936 series 40’s, and the Stromberg EE-22 used on the 1936 series 60’s. These were replaced by what might be called “experimental” carburetors. Both Marvel and Stromberg were asked to produce these carburetors. The carburetors were to be equipped with the Delco automatic choke units. Stromberg objected to the use of the Delco chokes, but these objections fell on “deaf ears” at least for a couple of years. Several different carburetors of both brands were used (see below) in 1937 and 1938, ALL with major drivability issues. The Marvels just plain had issues; the Stromberg issues primarily due to the Delco chokes, especially in 1938. During mid-1938, a bulletin was issued advocating absolute butchery on the Delco choke, but it didn’t really help. At best, the choke was disconnected, and the choke plate adjusted to always be open. This made the engines somewhat difficult to operate in colder climates. One distinguishing characteristic of the 1937 and 1938 Buick carbs is the “speedometer cable” connecting the Delco choke to the choke shaft. The flexible cable had a locating pin on each end that pressed into an indentation indexing the choke unit with the choke shaft.
In 1939, Buick had had enough of the drivability issues; discontinued the use of Marvel completely, discontinued the use of the Delco choke (thankfully), and added Carter to replace Marvel as their second carburetor supplier. Both Carter and Stromberg, AT BUICK’S REQUEST, offered replacement carburetors for both the 1937 and 1938 models of both size engines. These were offered through Buick dealers, as well as by auto parts houses.
Today, most enthusiasts that actually drive their Buicks replace the 1937 and 1938 original carbs with later Carters and Stromberg. Those that attempt to maintain original cars with original carbs generally at some time replace the Marvels with Strombergs. Be aware that a hot air stove, linkage modifications as well as an adapter to close off the exhaust port in the intake are necessary to utilize the newer carburetors.
Type BD 10-1749 – series 40 standard air cleaner
Type BD 10-1750 – series 40 heavy duty air cleaner
Type BD 10-1751 – series 60 standard air cleaner
Type BD 10-1752 – series 60 heavy duty air cleaner
Type CD 10-1762 – series 40 standard air cleaner
Type CD 10-1763 – series 40 heavy duty air cleaner
The type BD Marvel was basically a duplex (2-barrel) adaptation of Marvel’s single barrel model B. The BD still used the old cork float, although Marvel did incorporate a vacuum economizer system on the BD. Buick was the only company ever to purchase the type BD as original equipment, although Marvel did attempt to sell a few type BD carbs as aftermarket. With lots of drivability issues inherent to the BD, Marvel quickly came up with a new design type CD carburetor for late 40 series Buicks. However, the CD series continued with the cork floats. Again, Buick was the only company to purchase the type CD for use as original equipment, and I have no record that Marvel attempted to sell the CD in the aftermarket.
Type AA-1 7-12 – 40 series standard air cleaner
Type AA-1 7-14 – 40 series heavy duty air cleaner
Type AA-2 7-13 – 60 series standard air cleaner
Type AA-2 7-15 – 60 series heavy duty air cleaner
The types AA-1 and AA-2 were the first production models of Stromberg’s new type A series downdraft carburetors (there was a much earlier updraft A series). There is evidence that Buick was experimenting with compound carburetion in 1935 with 2 single barrel type A Strombergs, but that is another story. In Stromberg’s nomenclature, a double letter meant a 2-barrel carburetor; and the number following the letter(s) was the S.A.E. flange size of the unit. So the AA-1 is a two-barrel S.A.E. size 1 carburetor, and the AA-2 is a two-barrel size 2 carburetor. Only Buick used the AA-1, but Lincoln also used the AA-2. The AA-1 was to resurface in 1941 and 1942 as the rear (secondary) carburetor of Buick’s production compound carburetion. Like many first models, The Stromberg AA series did have some teething problems. Stromberg did use the double pontoon float, which gives much more consistent bowl fuel levels than the single pontoon. But Stromberg retained the mechanical economizer system from the proved EE series carburetors. The Strombergs would not have been bad carburetors without the Delco choke.
Type CD 10-1796 – 40 series standard air cleaner
Type CD 10-1797 – 40 series heavy duty air cleaner
Type CD 10-1798 – 60 series standard air cleaner
Type CD 10-1799 – 60 series heavy duty air cleaner
In 1938 Marvel continued the CD series on both the 40 and 60 series Buicks that was introduced on the 40 series in 1937.
Type AAV-1 7-17 – 40 series standard air cleaner
Type AAV-1 7-19 – 40 series heavy duty air cleaner
Type AAV-2 7-18 – 60 series standard air cleaner
Type AAV-2 7-20 – 60 series heavy duty air cleaner
In 1938, both series of Buick engines got the new AAV versions of the AA series Stromberg carburetors. Major engineering changes occurred from 1937 to 1938. The idle circuit and main metering circuits were completely reworked, as well at implementing a vacuum (hence the V in the type) economizer system. These basically were 1939 Strombergs, but still with the Delco choke which continued to give major drivability issues. Buick was the only company to use the AAV-1, but White used the AAV-2, and Stromberg also sold the AAV-2 to Bugatti. The AAV-2 was continued to be used on many models from many companies post 1938. In 1939, the Delco choke was finally scrapped, and the number 6 denoting hot air choke was added to each of the models. Thus the AAV-1 with hot air choke became the AAV-16, and the AAV-2 with hot air choke became the AAV-26. AAV-16’s were used primarily by Buick, but the AAV-26 was used by many different companies and models including Rolls Royce up through about 1950.