General Category > Quadrajet Carb Talk and Tips

Sec Hanger Height

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von:
  I read in another place that the specific hanger letter doesn't matter as longer as the hanger height is 41/64" from the top of the airhorn to the metering rod holes in the hanger (doesn't say whether top of hole or center), when the air flap is open and hanger is raised. Can anyone confirm or dispel that?

omaha:
I do not agree with that at all. Its a tuning tool that can have an effect on power. Everything else is the same except the hanger and the metering rod. the jet diameter is the same in all q-jets and it is non-removable. Yeah you can mess with the poe and the sec. well feed hole but that is just for the transition stage from prim. to sec. Different hangers will locate the TAPERED (imporant) metering rod at different heights in the jet hole. This has the same function as changing jet size. The cam that lifts the rods are the same also.  edelbrock sells different hangers. 4 or 5 I think.

von:
I understand what you're saying and agree in general. I have a list of different hangers and their specs. But it seems there should be a starting point for height of the rod holes, at least certain heights for certain rods (long, med, or short at least). There could be variances due to cam wear, hangers being bent, etc. I've heard an NHRA racer (Michael Beachy) makes a hanger bending tool for sale. I'm thinking, why have an assortment of hangers when they can be adjusted (bent) so easily. Maybe a range of hole heights from richer to leaner? Or 3 ranges for long, med, short rods?

omaha:
I guess if it were me I would start with one of Cliff's recipe's that would match up with the engine combination being used. Then, if changes were thought to be needed, they could be done either on the car and/or without removing the top from the carb. ( one of the few easy things to do on a Q-jet). The secondary rods and hanger are acessible from the outside of the carb. So then, hangers, rods and opening rate. Those are the BIG three elements used to tune the secondaries. The next part is the drag strip. Have fun!!

von:
  One of the reasons for asking is that when I first installed my old "F" hanger (which agrees with Cliff's second recipe), it was bent so far off that one of the the metering rods was coming up so high it was hanging up on the oriface in the main body. I first bent the hanger to conform to the 41/64" installed dimension but in measuring the hanger itself it was even lower than a "V" rod spec. So I bent it back to it's original "F" spec of .540  from the centerline of the hole to the underside of the hanger mounting surface. The spec is in an old version of the Doug Roe book I have. I believe the "F" rod agrees with the second recipe which calls for "G" or higher. I'd still like to hear Cliff's take on this.

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