Vacuum sec. holley ?

[old blue 75]

With a Holley vac. sec. carb(750 3310)is there a way to make the secondaries
open faster than the fastest spring will allow?I have the fastest spring installed and
the engine will still not stumble. I would like to find out where the limit is.

Thanks old blue 75

[rookie]

I’m not sure what spring you’re using but just FYI.

Holley Book shows,
White is the lightest (I have never seen white or short yellow) they don’t give rpm for this one.

Yellow (short) lighter, is next starts to open at1620 rpm, full open at 5680.

Yellow (long) light, (this is the one I have used the most) starts to open at 1635 full at 5750.

This is for 350ci and about 200 rpm sooner for 400ci.

At your own risk!!, instert a small sheet metal screw in front of the link between the primary and secondary linkage bar, this bar is to shut the secondary, so if you put the screw in the slot in front of the bar on the drivers side of the carb and it will become a mech. secondary and open instantly.

[Lasse]

Originally Posted by old blue 75

With a Holley vac. sec. carb(750 3310)is there a way to make the secondaries
open faster than the fastest spring will allow?I have the fastest spring installed and
the engine will still not stumble. I would like to find out where the limit is.

Thanks old blue 75

Why not make your own spring? With accurate scale you can measure spring rates from old spring and new custom spring.

Lasse

[Cammer]

Locking the linkage will not give you a mechanical secondary carburetor! You will have a vacuum secondary carburetor with the primaries and secondaries locked in some degree of similar opening.

I wish I had a dollar for every one of these cobbled up carburetors I have had to straighten out!

[rookie]

mechanical - using (or as if using) mechanisms or tools or devices; "a mechanical process";

Dbl. pumper it’s not - mechanical it is.

Not all that different from a Holley 9776