Anyone know how I can tell which metering needles I presently have in my Stromberg 175 CD-2 carburetors? I have removed all emissions equipment and that may require a needle change?

 

Bill,
When you say all, did you remove and plug the " temperature compensator" on the side of the carburetors? This will let more air in to lean mixture when engine is fully warm.

https://mossmotors.com/jxj-7983-stromberg-carburetor See # 37 and # 23

You probably have the original needle P/N. The later P/Ns were to tighten down emissions and would be worse than you original P/N needle for performance.

Two options: convert to adjustable needle (same profile) or convert to adjustable jet. Ask Joe for his advice. I sent him 3 Zenith Stromberg 175 CD-2 carburetors, and he converted them to adjustable needle. He has parts for both and you can do the work yourself. CALL TO ORDER PARTS 718-762-7878 JoeCurto@Aol.com
Rgds
David

 

My preferred approach is to get a wideband O2 sensor and and exhaust clamp and see if the car is rich or lean and try tuning it. You may just need an adjustment, or nothing at all, the gauge will tell you where you are.

 

The problem is they (Stromberg 175 CD-2 carburetors) were smog carbs with no mixture adjustment, i.e. no tuning. They came new with lead seal and all you could do is install seal kit at your dealer, who could put a new lead seal on. If you had a worn needle and replaced it, you would go even leaner. By removing the emissions secondary throttles and Cross Over tube to exhaust and back for idle mixture heating, you had less anatomization of the fuel and a poor idle. The fix is to richen the idle mixture, which is option not provided for on a smog carb. The same carb was available in UK with the adjustable needle, so parts eventually made it to the US, as most states stopped monitoring the older cars.
The fixed needles ridge were to be installed flush with the bottom of the piston, but you could grind the tip of the needle off, and push needle into the piston 3/32" from flush. Then secure needle with set screw. I know this from experience.

 

Mine is actually the adjustable metering needle. And yes, I still have the temperature compensator. Car actually runs very good. I just figured that with all that I removed, it might call for a needle that was pre-emission controlled systems. Might even have it run better?

 

"Mine is actually the adjustable metering needle.... and Car actually runs very good."

Bill, I think you have it all?
Maybe another hand wax this weekend!!!!
Rgds
David

 

[QUOTE=David84XJ6;2667148]"Mine is actually the adjustable metering needle.... and Car actually runs very good."

Bill, I think you have it all?
Maybe another hand wax this weekend!!!!
Rgds
David[/QUOTE

Good point. And... my ignition switch just failed!!! So now I have that project!!!