Edelbrock 1406 accelerator pump

[1973dust]

I freshened up my 600 yesterday and the pump plunger that came in the kit sticks down into the well farther at rest than the original. I went ahead and used the new one as it has a brass
stem and appears to be much better made than the original. However, after driving the car, I don't think it feels as good as with the original. I ending up moving to the linkage hole closest to the carb, which seemed to help but it still doesn't feel as good as what I started with. Has anyone else run into this? I'm tempted to just swap the new rubber seal to the old plunger, but as I said, the new one is brass and the old one has a plastic stem. Thanks.

 

[Brooks James]

I freshened up my 600 yesterday and the pump plunger that came in the kit sticks down into the well farther at rest than the original. I went ahead and used the new one as it has a brass
stem and appears to be much better made than the original. However, after driving the car, I don't think it feels as good as with the original. I ending up moving to the linkage hole closest to the carb, which seemed to help but it still doesn't feel as good as what I started with. Has anyone else run into this? I'm tempted to just swap the new rubber seal to the old plunger, but as I said, the new one is brass and the old one has a plastic stem. Thanks.

Did you research a leather cup plunger ??

 

[1973dust]

Did you research a leather cup plunger ??

No, didn't even think to do that. I don't know if the old Carter style interchange with an Edelbrock or not.

 

[pishta]

Carter old is leather carter/brock/weber is plastic and rubber. I dont think the 2 cups can interchange. Thats crazy the leather lasts in fuel.

 

[65TerrorCuda]

I think you can bend the linkage to the pump to adjust how far in the well the cup sits. It might be in the owners manual

 

[Brooks James]

No, didn't even think to do that. I don't know if the old Carter style interchange with an Edelbrock or not.

Ill bet it does fit

 

[Brooks James]

Carter old is leather carter/brock/weber is plastic and rubber. I dont think the 2 cups can interchange. Thats crazy the leather lasts in fuel.

Cup size Maybe. The new ones have a removable cup. Old , the leather can expand and contract more and is permanetly attached

 

[1973dust]

Carter old is leather carter/brock/weber is plastic and rubber. I dont think the 2 cups can interchange. Thats crazy the leather lasts in fuel.

I think you can bend the linkage to the pump to adjust how far in the well the cup sits. It might be in the owners manual

Just to make sure I'm not confusing everyone, I'm working on a Edelbrock/Weber 1406 600 cfm. Both the old and the new cups are rubber. The distance from the "flange" on the stem to the s-hook hole on both is the same but the length from the flange to the cup is at least a 1/4" more on the new plunger. The spring is also much heavier. I think it's more than can be compensated for with the linkage. It seems like the new one is wrong but maybe I'm misunderstanding how it operates.

 

[RustyRatRod]

Cup size Maybe. The new ones have a removable cup. Old , the leather can expand and contract more and is permanetly attached

I agree, I like the leather better, ultimately, but it has one bad shortcoming over the newer rubber. It's not ethanol friendly. Ethanol dries the leather out terribly. Non ethanol gas didn't do that. But let them sit dry for any length of time after being submerged in ethanol gas and the leather cups are done for.

 

[pishta]

the cup height determines the amount of shot into the carb, (the depth of the shot is the variable, the height I think is fixed to allow fuel slot to fill the pump cavity) the and this is determined by where you hook the linkage to on the arm. the 3 holes have 3 different pump volumes.

 

[1973dust]

the cup height determines the amount of shot into the carb, (the depth of the shot is the variable, the height I think is fixed to allow fuel slot to fill the pump cavity) the and this is determined by where you hook the linkage to on the arm. the 3 holes have 3 different pump volumes.

Your explanation is how I thought it should be. I'm starting out with the cup at a much lower height, therefore I'm getting less volume from a shot. I think I'll try putting the old plunger back in with the new cup and actually measure the length this time while I have it apart. I'd like to at least have an extra after seeing that the stem is plastic on the old one.