I’ve been fascinated by these old relics ever since I took my first one apart in in my Dad’s back yard 1961. Been flogging them, off and on, ever since and still build each one like it was for myself, be it for someone’s restoration project or a 6×2 hotrod application. Or anything in between!
I start by disassembling and checking everything, including leak testing the floats.
Emulsion tubes, idle jets are removed & replaced with fresh acid etched parts. All main jets, powervalves, accelerator pump, fuel inlet, gaskets checkvalves etc. are new.
Bases are stripped and glass beaded, surfaced on both sides, all threads chased, new SS bushings (parallel reamed to .278″) and standard .275″ diameter throttleshafts. Epoxy gloss black fuel-proof paint and my own Fatfinger extended knurled mixture screws…
Airhorns are brought back to flat and lightly surfaced. All carbs are fitted with chokeplates. Contrary to the old thinking of removing the chokes for “more flow”, the plates are necessary to provide a smooth airstream over the open ends of the discharge jets for proper venturi signal and atomization of fuel. They just run better… I use an aircraft in/lb torque screwdriver on all top screws.
On a 2×2 rig, I use a clever stainless choke lock-pin that goes in place of the bullet detent on one carb to prevent the plates from flapping in the breeze; it allows the chokeplate to be secure in the upright position. (You only need one functioning choke, even in the coldest climate).Center-Sections have all jet-well and fuel inlet surfaces spotfaced. I promise no leaks, unless you want them for authenticity!
Bodies & airhorns are ultrasonic cleaned and acid treated. The chromatic acid leaves a grey/green/pewter colored barrier coating, which is impervious to fuel & mineral deposits and should last another 70 years.
All linkage, including chokekicker, fulcrum, pump rod, throttleplates & choke plate are newly plated.
All external springs are heat treated 302 stainless, including the slightly heavier duty accelerator fulcrum spring which makes for quick throttle response.
A lot of guys don’t realize that in a properly functioning Stromberg – with new parts – that the powervalve starts to come to the party the moment you stab the gas, due to the hydraulic action of the accelerator pump, and becomes fully open at the bottom of the stroke. If you step on the gas less violently, the built in bypass valve in the pump takes over, for a smooth transition. Simple, but effective… That’s why it’s important to marry the jets and pv’s for correct A/F ratio for different applications.
All carbs are flow checked…
Carbs are built to order, usually 6 to 10 days.