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Secondary Throttles on Stromberg Federal TCSs.
Bryan Boyle:
Question:
Loose and block off the shaft openings (removing the levers and bits from the carbs to actuate)?
or
Keep?
(as an aside, before removing the carb stack this afternoon, measured the clearance from the adapter plate to the secondary body...there was NO gap; the thackery washers were torqued down tight. O-rings in the secondary body were hard as a rock (the front carb had orange RTV around the ring...uh, no. Not proper. Replace the damn o-ring, don't goop up with RTV. Damn DPOs.)
Kendo:
Mine had the secondary shafts and butterflies removed. It reduces impediments to airflow, and the shaft holes are probably easier to seal than the shafts.
Just my two cents. It's also been suggested to flip over the secondary manifold to produce a sort of Euro-style high balance tube manifold. But I haven't really evaluated that.
Grumblebuns:
I suppose you could try to remove just the butterflies themselves if that is possible and keep the shaft in place but then the shaft holes could be source of air leakage past the shaft. It might be simpler to totally remove the entire secondary butterfly assembly.
Ken, thinking about your idea to flip over the inlet manifold to create a balance tube effect. I believe with the stock setup in place, and the butterflies closed, the air/fuel charge enters the bottom passage in front of the butterfly, and exits the inlet manifold into one of the crossover tubes over to the exhaust manifold back to the other crossover tube and back into the inlet manifold and exits behind the closed butterfly. Most owners just block off the crossover tube passages on the inlet manifold. Can somebody explain how a balance effect is created with the crossover pipes blocked off? I should probably look up the system in the manual.
Thinking it over, it appears that both passages connect internally maintaining the balance.
Kendo:
I still meant to remove the butterflies and shafts, and close off the crossover tube opening. With all of that done, I think the two carb throats are connected by a balance tube that runs along the bottom of the casting. So, rotating it 180 degrees would put the balance tube on the top. I haven't done this. I just read about it (probably here) and thought it would be worth looking into the next time I have the carbs off.
Bryan Boyle:
--- Quote from: Kendo on Monday,March 07, 2022, 01:13:43 PM ---Mine had the secondary shafts and butterflies removed. It reduces impediments to airflow, and the shaft holes are probably easier to seal than the shafts.
Just my two cents. It's also been suggested to flip over the secondary manifold to produce a sort of Euro-style high balance tube manifold. But I haven't really evaluated that.
--- End quote ---
so what would be the advantage to that (besides eliminating perhaps a locus for the fuel to puddle (fwiw, the cross over tubes were deleted and the mounting flanges blocked off at some point in the hairy past on this car...).
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