Push hard and live
Join Date: Apr 2007
Location: Carson City, NV
I’m working from memory here, as I just discovered all of my old Weber manuals were stored in the leaky section of the hangar. Dang.
My recollection is that the float level was specified differently for different cars. I believe there to be four primary variables:
The vacuum level created by the engine. This can be significantly varied by cam profile, overlap, cc, etc.
Aux Venturi size, and
Primary Venturi size
Emulsion tube used
Thus, if you’ve hotted up your engine from stock, the stock float level may not work.
The float level primarily determines at what RPM the main circuit tips in, acting in harmony with the E-tube.
My recommendation is to experiment first with float level changes before messing with E-tubes.
You can determine the idle circuit upper RPM limit by removing all four E-tubes, and going for a slow drive on just the idle circuit. Slowly accelerate until you sense the power has peaked. That’s where your idle circuit has rolled off.
Start with whatever E-Tube you think is right, and the float at 28 mm below flat surface around E-tube wells. Accelerate smoothly. If you get a steady increase in torque, you’re probably good. If you feel a slight slump around the RPM limit for your idle circuit, raise the float level one or two mm and try again. It should feel good with the float level somewhere between 24 - 29 mm, or you’ve got other jetting problems. Your mains and airs ought to be close to what the various charts recommend. The E-tubes are the mystery. Generally, F16 will work, but give you a rich transition.
You might get connected to Keith Franck at “sidedraftcentral.com.”
Carson City, NV
59 102 Touring (first Alfa $500 running)
65 Sprint GT (2nd Alfa, $500 daily driver)
102 Sprint (never did anything with it, but wish I had)
74 Berlina (first new car - now certainly rusted into oblivion)
61 Giulietta Spider G-Prod Race Car (where is it now?)
84 Spider Veloce (rarely drove it, so sold it)
86 Quadrifoglio (Dull car - no more 115s for me)
1971 Montreal "The Full Monty". Fair winds and following seas
59 102 Touring Roadster - restoration complete, enough Alfa for any rational man. Or irrational, for that matter
Oops. Add to the "present" list, 10204 01488, 2000 Touring Roadster project
Two 1946 Stampe SV4C (c/n 294 "Rocinante" - wife's favorite airplane. RIP), and c/n 235 "La Bon Temps Femme" (gone to a new home, but never forgotten)
Zlin 50LA (+9 -6 gees, titanium spar, 1200 lbs, 260HP rumored to now be in Brazil)
1946 Luscombe 8A
Starduster Too (recently spotted at the Nevada City, CA airport - over 20 years and an entire continent separating it from our stewardship in Binghamton, NY)
1955 Cessna 170B (wife taught me to fly tailwheel in this)
64 Mooney M20E ("Rambo". My faithful steed for over 40 years) Over 55 years old, and just returned from a trip to Argentina in him
Newest in the fleet
1967 Piper Super Cub on Wipline amphibious floats (a true "all terrain vehicle")
2010 Triumph Thunderbird
You can snap roll an Alfa only one time...