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yes guys, another 1920 question
https://slantsix.org/forum/viewtopic.php?t=18808		 Page 1 of 1
Author:  JDS [ Tue Jul 25, 2006 3:58 pm ]
Post subject:  yes guys, another 1920 question
okay so this is what i understand to be correct, the accelerator pump gives a shot of fuel to counter effect the lag between the idle circuit and main. it is controlled mechanically by external linkage...

now what the "economizer" does is where i get fuzzy.. how is this nasty little thing actuated, and what is it designed to do..
Author:  SlantSixDan [ Tue Jul 25, 2006 5:09 pm ]
Post subject: 
"Economizer" is just Holley's cutesy name for what everyone else calls the power valve and actuator.
Author:  DusterIdiot [ Tue Jul 25, 2006 5:21 pm ]
Post subject:  Sales Jargon...
Like Dan said it's a cutesy name for the power valve... the Holley reasoning behind the power valve on cars is so you can run a lean set of jets for cruise and have the valve come in during certain acceleration instances and provide the extra gas (i.e. "Rich" condition) needed.

-D.Idiot
Author:  JDS [ Tue Jul 25, 2006 7:20 pm ]
Post subject: 
okay so what acuates it? the lever inside the bowl on the bottom, or vacum from the top, everything appears to be fine , but i don't believe mine is functioning properly.
Author:  SlantSixDan [ Tue Jul 25, 2006 7:59 pm ]
Post subject: 
Quote:
okay so what acuates it? the lever inside the bowl on the bottom, or vacum from the top


There's a little potmetal cap atop the float bowl on the driver's side, held down by 3 screws. Under that cap is a rubber diaphragm and reinforcement plate, to which is attached a spring-loaded stem. The bottom of this stem has a metal "coin" on it. Directly below this "coin" is a nylon pivot arm hinged to the outboard end of the metering block. Its job is to translate the up-and-down motion of the "coin" 90°. At this arm's other end is a little spike. When the arm is pressed down by the coin, it rotates, causing the spike to press a bearing ball that is spring-loaded to the rear of a brass ring staked into the outboard end of the metering block. When that bearing ball is pressed off its brass-ring seat, fuel flows around the ball and into the metering block.

When manifold vacuum is high, it pulls the diaphragm upward against the stem's spring, the "coin" moves up, and the bearing ball's spring pushes the ball against its seat, which means the power valve is closed. When manifold vacuum drops, the stem spring pulls the stem down, the "coin" pushes the pivot arm, the pivot arm pushes the bearing ball off its seat, and the power valve is open.

(in 1962-1963 Holley 1920s, the "coin" acts directly on a metal-to-metal pin-and-taper valve protruding upward from an extension on the outboard end of the metering block, but the principle is the same.)
Quote:
i don't believe mine is functioning properly.
That'll be nothing but an unpleasant memory once you bolt on your new carburetor! :-D
Author:  JDS [ Wed Jul 26, 2006 1:12 am ]
Post subject: 
this is true!
but for now, the car mocks me at every stoplight.
hmm, i imagine that the actual movement of the diaphram under the potmetal is minimal,
thus the movement of the entire system is minimal,
translating to- very sensitive,
meaning a mass produced cheap rebuild kit being slightly out of spec enough to make the whole deal misbehave.

is there a way to adjust the powervalve at all? seems like maybe giving it a little more oomph here could be the ticket, it stumbles off idle but the initial second or two its fine then stumbles. i think the accel pump is fine, since the car gets it initial little of idle boost then falls on its face before catching its breath. i toyed with all 3 positions on accel pump with not much seat of the pants difference to me. once the economaster gets here i might just adjust this one with my hammer, that way it can never end up in some other poor fellows car and ruin his day too...
Author:  Eric W [ Wed Jul 26, 2006 2:24 am ]
Post subject: 
I don't think there is anyway to adjust the power valve, unless Dan or others know some tricks. What size is your jet? Some off idle hesitation and part throttle hesitation can be attributed to the size. My experience: First got the Satellite (car in my sig), bad bog off the line and on the freeway when climbing grades, no matter how much I played with the timing or carb adjustments (idle screw, float setting, accelorator pump rod). Looked in the carb (Holley 1920 like yours), and pulled the #55 jet out, installed a #62 I had laying around. All hesitation gone, gas milage dropped though. After playing around with different jet sizes, found a #58 workes best for my engine and driving style.
Author:  SlantSixDan [ Wed Jul 26, 2006 7:06 am ]
Post subject: 
Yeah, total active system movement is small, maybe 3/16". There's no adjustment, but it's worth noting that while the original stem springs were application-specific, most of the carb kits available today have a "one size fits all" stem spring that may or may not match well with your carb. Also be advised that after so many years and so many rebuilds, the metering block can just plain stop working, and then it's "end of the line", no fix possible. That may be what's going on for you right now.
Author:  JDS [ Wed Jul 26, 2006 10:16 am ]
Post subject: 
"end of the line" huh? its hammer time!
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