Author Topic: Accelerator Pump Specs  (Read 2671 times)

Offline cch80124

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Accelerator Pump Specs
« on: July 23, 2013, 08:11:34 AM »
I have about 8 QuadraJet carbs, two of which are bushed, and alternatively used on the same SBChev, when its alternate is off for minor cleaning.  Thus neither is disassembled at the same time.  The carburetors are 7040502 (old service replacement, Calif spec) and 7042902 (Calif spec).  Both are Chevrolet pattern.

I know there are a couple of different pump cups and many lengths of plungers.  Upon last purchasing a pump cup, the issue arose that the thickness of the listed cup (NAPA) where it attaches to the plunger was very different from the plunger.  So I opened the installed carb to discover its different plunger length and the fact that the cup for the other carb fit the installed carb.

A lot of perhaps excessive information to address the question as to accelerator pump specs.  Is there a list of part numbers, plunger lengths, spring lengths, plunger to cup dimensions, et al to carburetor numbers?

TIA

Offline Ethan1

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Re: Accelerator Pump Specs
« Reply #1 on: July 26, 2013, 11:34:06 AM »
I have about 8 QuadraJet carbs, two of which are bushed, and alternatively used on the same SBChev, when its alternate is off for minor cleaning.  Thus neither is disassembled at the same time.  The carburetors are 7040502 (old service replacement, Calif spec) and 7042902 (Calif spec).  Both are Chevrolet pattern.

I know there are a couple of different pump cups and many lengths of plungers.  Upon last purchasing a pump cup, the issue arose that the thickness of the listed cup (NAPA) where it attaches to the plunger was very different from the plunger.  So I opened the installed carb to discover its different plunger length and the fact that the cup for the other carb fit the installed carb.

A lot of perhaps excessive information to address the question as to accelerator pump specs.  Is there a list of part numbers, plunger lengths, spring lengths, plunger to cup dimensions, et al to carburetor numbers?

TIA

 I would call Cliff's shop. He will know which cup you need. And from what I have been told, is accelerator cups are the BEST on the market.
Ethan

1972 Chevelle

(oo______oo)

Offline Cliff Ruggles

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Re: Accelerator Pump Specs
« Reply #2 on: July 30, 2013, 04:31:41 AM »
The best move is to upgrade to the later pump design, and throw all those old pumps in the trash.  They currently do NOT make a good seal for them.  Even the blue "Viton" seal is soft and swells up and sticks in the pump bore or comes off the pump and gets wound up on the spring.

We sell a much better pump with custom wound springs, and a Viton seal that will not fail in this new fuel.....Cliff