Stromberg OT-3 Carburetor Application

[PartsAncient]

I have an OT-3 Stromberg Carburetor.  This Carburetor is in really excellent condition. 

 

The throat bore is 1 5/8"

The mounting flange has two 3/8" NC threaded holes, 3" OC

 

I used to own a 1923 Stutz four cylinder, detachable head, Speedway roadster.  As I recall a similar if not exactly the same carburetor was used on that car. 

 

I would appreciate any application information on this carburetor.

Thanks,

Glenn

 

 

 

 

[Mark Gregush]

From" RADCO CARBURETOR AND MOTOR TUNE-UP MANUAL, 1925 TO 1930": Under Stromberg O and T; "The model OT is similar to the OE but cast in brass with special heavy construction to render it suitable for truck and motorbus service. It carries a special heavy duty float mechanism. This model is made in 1-1/4, 1-1/2 and 1-3/4 sizes. The 1-1/2 being unusaual in that the throttle shaft is parallel with the center line of the flange holes which flange holes are in line with the air entrance of float chamber in all the OT models."

Sorry can't be any more help. All my books are car information, no trucks or motorbus. 

Edited May 5, 2022 by Mark Gregush (see edit history)

[carbking]

I show 47 different applications in my database.

 

Jon.

[edinmass]

1 hour ago, carbking said:

I show 47 different applications in my database.

 

Jon.

 

Yet they are all the same, I am positive, because I read it on the internet. 🤡

[carbking]

21 hours ago, Mark Gregush said:

From" RADCO CARBURETOR AND MOTOR TUNE-UP MANUAL, 1925 TO 1930": Under Stromberg O and T; "The model OT is similar to the OE but cast in brass with special heavy construction to render it suitable for truck and motorbus service. It carries a special heavy duty float mechanism. This model is made in 1-1/4, 1-1/2 and 1-3/4 sizes. The 1-1/2 being unusaual in that the throttle shaft is parallel with the center line of the flange holes which flange holes are in line with the air entrance of float chamber in all the OT models."

Sorry can't be any more help. All my books are car information, no trucks or motorbus. 

The Radco information is somewhat accurate, but not entirely.

 

Most of the model OT units more closely resemble the model O than the model OE.

 

The model OT was made in 4 different flange sizes (S.A.E. sizes 2 through 5), a 2 inch size in addition to those listed by Radco. As with virtually all Stromberg carburetors, the number following the letters in the model represent the S.A.E. flange size. The OT-3 is an S.A.E. size 3 (nominal 1 1/2 inch).

 

The heavy truck and motorbus application is correct, with one of the model OT-2 also being used on a tractor.

 

And every time I machine a new fuel valve for a rebuilding kit I am reminded of the "special heavy duty float mechanism". Generally, a few words are spoken!

 

Jon

[edinmass]

Driving around on your carburetor kit right now. 

[edinmass]

Runs great. Typical hundred point car that had never been sorted. Twenty problems of poor workmanship, now all fixed. 

[Peter R.]

On 5/5/2022 at 9:50 PM, PartsAncient said:

I would appreciate any application information on this carburetor.

Thanks,

Glenn

According to the body number on the flange, your OT-3 came off of a 1929 Mack Model BG or BL Truck.

[PartsAncient]

Thank you, for your assistance!