Stromberg OX-2 adjustments

[gundog99]

My 2249 Dodge Senior is fitted with a Stan Howe restored OX-2. The High Speed mixture adjustment is 2 1/2 full turns from stop, what I am not sure about is the Idle mixture adjustment: Stan Howe recommends 3/4 turn from stop but I have read that I should consider one or two full turns.  

[nearchoclatetown]

I know nothing about your carb, BUT apparently Stan Howe does. I would at least try his suggestion. PLUS, the new ethanol crap is said to need smaller jets, adj. etc. then REAL gas. Maybe that is his reasoning. I would at least put it on and drive it to see how it works. THEN decide to change it.

[carbking]

Stromberg made dozens of DIFFERENT type OX-2 carburetors.

 

Dodge never used a Stromberg OX-2 as original equipment.

 

Since Stan rebuilt the one in question, we can assume it is calibrated for the early 1928 Dodge Senior Six (Dodge used a TX-2, which is basically a zinc version of the OX-2). An OX-2, properly calibrated for an application would have a suggested initial setting of 2 1/2 turns on the high speed, and 3/4~1 turn on the idle.

 

If someone wrote they used 2 full turns on the idle, it might be a "band-aid" setting masking a very rich condition (leaking float valve, electric fuel pump, etc.). 2 turns out on a proper carb would be extremely lean! Some enthusiasts do not realize that most of the updraft (and many early downdraft) carburetors had an "inverse" idle circuit; that is, the control screw metered Air, NOT fuel. Thus the richest condition would be with the idle control screw turned all the way end. Rotating the screw out would introduce air into the idle circuit, leaning the idle mixture.

 

I would try Stan's suggested setting FIRST!

 

In the category of useless trivia; Dodge rapidly found that the size 2 carb (TX-2) was too small for the Senior Six, and replaced it in mid-1928 with a size 3 carb (UX-3). I might suggest that, while it might be expensive, the OP might look for the later intake manifold, and the larger carburetor. The UX-3, like the TX-2, was zinc, and good castings are about as rare as winning an argument with the IRS; but Stromberg made the OX series in a size 3 (the OX-3) in brass.

 

Oh, and the high speed adjustment is conventional; that is, in to lean, out to rich.

 

Jon

[gundog99]

Thank you for you helpful response; my Senior is an early RD model with the smaller intake Manifold. I have set the OX to Stan's recommended settings ,but the 3/4 to 1 gives me some more tuning  options.