hey everyone,

I currently have a 350 w/ stock centerbolt heads, edelbrock performer rpm intake, holley 4160 600 cfm carb, edelbrock shorty headers. I can't seem to get my secondaries to cooperate with me. I have the holley secondaries quick change kit and currently have the heaviest spring in there, but it seems as if they are still opening really early. The car bogs pretty bad when I get on it and I feel the secondaries open.

What advantages (if any) would I have with a double pumper? could I adjust how the secondaries act more with a double pumper than I can with a regular setup? If I were to go w/ a DP, what size would you recommend?

also could this bogging be b/c of jets that are too big? any help is appreciated so I can get this thing running as well as it can

 

We're a little short on information here, such as: what cam, what exhaust (after the headers), what drivetrain, what distributor, etc.

The distributor is an important one. You don't by any chance have a factory distributor in there still, do you? If so, big problem. The ignition absolutely has to be up to snuff before you start working on carb problems.

By any chance, has the secondary check ball been removed? That can happen accidently, or someone thinks it shouldn't be there (or doesn't know it should be). If missing, big bog.

Too rich isn't likely. Should actually help.

Double pumper typically makes bogging problems really bad on an automatic car, if the carb is otherwise properly sized. That's why vacuum secondary carbs exist.

 

ok sorry about that missing info

I have a custom y-pipe going to a hollow car and then the stock 2 1/2" intermediate pipe, and a flowmaster 80 series muffler. The cam is stock for this motor (bought it complete w/ 30k miles on it) and I don't know the specs on it, sorry. I have stock 308 singletrack gears and a 700-r4 trannie.

I have an MSD super HEI ignition module, hypertech supercoil, cap, and rotor, in a brand new HEI distributor (not sure what brand), w/ MSD superconductor 8.5mm wires

I bought the carb brand new and didn't take out the check ball.

let me know if you need anything else

 

With a double pump carb, the secondaries will just flop all the way open. How is the float level in the front and rear bowls? If changing the spring to the stiffest didn't help, I would say that isn't the problem. Is the fuel pump keeping up with the demand?

 

Did the carb come with the quick change spring kit, or did you install it? Even though you didn't take the check ball out, are you sure it is there?

The 4160 has a secondary metering plate, not jets. A 600 on an otherwise healthy 350 may actually be lean.

Absolutely check the float levels. Along with ignition, that is something that has to be right before any tuning is begun. A weak fuel pump should be exposed as power is building, not as soon as the secondaries open, but it is possible you don't have enough fuel in the secondary bowl.