WTB Intermediate flange for AAV26

[Guest Two Roadmasters]

Anyone having the intermediate flange between intake manifold and carburetor for an AAV26. The one I have has a worn out shaft but the carb is OK. I will eventually change my Marvel on my -38 Roadmaster if I manage to get one. The pipe between manifold and choke house is also missing.

Any help is highly appreciated.

Mats Ahrin

Sweden

[carbking]

Mats - Stromberg made many DIFFERENT flange assemblies for the AAV-26 series carburetors. They are not interchangeable.

Try taking the throttle shaft to a local machine shop and have a replacement machined. This way your throttle body (with a new shaft) will match your carburetor.

Clearance of the throttle shaft to the throttle body was S.A.E. 0.004~0.006 inches. According to an online conversion calculator, in metric this would be 0.106~0.152 millimeters.

Jon.

[carbking]

Mats sent an email requesting more information on this issue, especially the interchange. As the answer may be of use to others, I am posting it here.

Mats questioned why a throttle body from one AAV-26 may not be the same as another.

The term "AAV-26" is "decoded" as follows"

A - series "A" carburetor

A - a second repetitive letter means a two-barrel

V - vacuum controlled power system

2 - S.A.E. size 2 flange

6 - hot air choke

We have 46 listings for AAV-26 carburetors.

The number that will specify the actual part number of the AAV-26 carburetor (and will aid, through the use of a Master Parts Book in interchangeability) is STAMPED (not raised) on the top cover (airhorn) of the carburetor. If one looks at the top of the top cover of the AAV-26, one will observe 4 screw holes along the front, and along the back. If one looks at the top along the sides one will observe the stamped number. The number will have a one, two, or three digit number followed by a dash followed by a one, two, or three digit number POSSIBLY followed by a letter.

These numbers are decoded as follows:

first set of numbers - manufacturer for which the carburetor was intended (Buick is 7)

second set of numbers - the sequential number (or tag number) for this unit and manufacturer

letter (optional) - if present, represents a major engineering change

This listing may prove useful:

http://www.thecarburetorshop.com/Kbuick2.htm

Note for 1940, Buick used 2 AAV-26 carburetors (7-33, and 7-34). Without looking at the blueprints, my guess is that one is for the standard air cleaner, the other for the heavy duty air cleaner. But the example is for the stamped number ie 7-33. If this carburetor had one major engineering change, the number would be 7-33A; a second major engineering change and the number would be 7-33B, and so on.

If one is trying to interchange parts, one would know for sure the parts would interchange IF the numbers on the airhorns match. Otherwise, one would need to consult a Master Parts Book and check the individual parts which are desired to interchange.

[Patrick W. Brooks]

Hello Carbking: Thanks for the very interesting posting about carbs and their coding. Have recently encountered the problem of identifing which AAV-26 goes on my 1940 Buick Century. Have several and are unsure. Could you help by identifing their various applications. They are as follows:

P 24599

P 234936

P 23913

24599 Can't read all the stamping.

Thanks for your efforts and time. You may contact me directly at Brooker50158@hotmail.com or on this thread. My phone number is 641-753-9134. Postings by professionals like yourself are very helpful and identify those who are competent to give us fine service. Thanks, Patrick W. Brooks