New carb in my future

[rgtrough]

Hey guys, I am not liking the performance of my old Holley 4110 700 cfm dual inlet carb. It does not seem as if the secondaries are opening. They are vaccum.I am considering a new carb and am curious about mechanical secondaries. Any good? I will post my mods below. Also I have the comp cams 280h in her with 1.6 roller rockers. Thanks for being here for guys like me. peace Bud

 

[JohnZ]

Why spend the money for a new carb? Just check it and find out why the secondaries aren't opening. Put a dab of grease on the carb base where the secondary shaft stop bottoms out at WOT, go out on the road and romp on it, and if you see grease on the secondary shaft lever, you know it's opening all the way. If it isn't, try a lighter spring (get the Holley quick-change spring kit with the new cover so you don't have to take the secondary diaphragm housing off the main body to change the spring - it comes with seven springs).

Most "secondaries don't open" are because someone didn't replace the tiny cork gasket between the housing and the main body when they rebuilt it or removed the housing - that's the internal venturi vacuum passage that operates the secondary diaphragm. Vacuum secondaries are the best setup for a normal street-driven car.