Re: Bigugly..what\'s up w/ the Edelbrock
Yes, blocking the rear passage at the back on an AFB helps with sidehills. Helps keep the upside bowl from draining into the lower one. But it could cause uneven fuel distribution on hard acceleration uphill or even on flats. Notice the fuel inlet feeds one side, then it depends on the crossover passages to fill the other side. So during a hard load the opposite side may experience a lack of fuel, so every other cylinder in the firing order will go lean.
You won't feel it as a missfire, just not get as much power as you should.
An intake maniflod with a common plenum chamber (or milled out between the chambers) helps that problem significantly, but that also makes for a rougher idle and possible "tip in" stumbe. It's not a cure, it still goes lean, but the lean cylinders get a little more fuel, and the normal ones get leaner. So bigger jets help.
The AFB's floats are end pivoted, so uphill, or hard acceleration the fuel sloshes to the rear, dropping the float and bringing in more fuel. Not a problem as long as it's not too much - keep the float about 3/16" lower than the specs call out.
With the rear passage blocked off, the front passage is too high to transfer much fuel to the opposite side.
Going downhill fuel sloshes forward, shutting down fuel flow because of the float pivoted on the end. Sometimes going down a sandy hill you need power to straighten it out, ooops, engine's dead. Can get scarey when you get sideways bad.
The Q-Jet's floats are pivited more centrally, so hills are less troublesome -- but they still experience the same problems, just takes more angle to get in trouble.
Holleys are fine on sidehills IF they are the center-feds. But up and down hills they suck. Use jet extensions to get the jets to suck from the center of the bowl. And, use the vent extension (white whistle) inside as well as the external vent extensions.
Somewhere a long time ago I saw an article on using an aircraft stunt carburetor -- all positions - neat. Unfortunately I haven't seen anything about it since. Anybody know?