secondaries won't open on holley 3310
I have a holley 3310 750 on a mopar 380 horse crate motor.
Ok. That's should work fine. What revision 3310 - ?
With the carb installed I have used the paper clip on the diaphragm rod trick to check the secondaries.
Is it all the way against the housing?
The secondaries will probably not open fully but only to the amount needed based on the velocity through the primary side. So even at 6000 rpm, depending on gearing (load), volumetric efficiency, etc. doubt the 340 will open the 3310 fully.
I have run the car full throttle through all the gears and also just left it in drive and gradually accelerated to full throttle but the secondaries never open.
H'm.
Where did you test this? I can tell you that at WOT from approximately 3000 rpm up there is a measurable difference in acceleration, power, and ET when the secondaries are disconnected.
Could it be the carb is too big for the application? 67 barracuda with auto, 10 inch converter, dougs headers. 3:55 rear.
Not too big. I ran a 3310-3 on my 67 notch with 340 comp-280 cam, manifolds, and 3.23 gearing. about 3000 stall
I did tweak it a little for better idle and off-idle but not so much that it would have radically changed the acceleration performance.
Does anyone have any ideas on why the secondaries won't open?
Its possible something is holding the velocity back. If its not pulling hard enough on the primaries, it won't open the secondaries. For example primary jetting too rich or timing curve way off.
When you've eliminated the possible mechanical issues, we can come back to the possibilites of timing and jetting.