Can you inhibit the secondaries on a Qjet?

[OldCarPilot]

I want to keep the secondaries from opening on my Qjet. This has become a car that I am driving more of a distance than I used to, so I'd like to save some gas if I can. Car isn't fast enough for me to worry about haveing the secondaries open anyway.
I know... I know... "Get a 2bbl". I just don't want to spend the money right now and on this car.

[AHotRod]

YES...just remove the rod that connects from the primary throttle arm to the secoundary arm, and bingo, you know have the economy of the primary side only. No other changes are required.
Glenn

[DrJ]

You'd be better off leaving it as designed and just put stronger return springs on it so you'r lead foot doesn't get into your pocket so easily.
The Q-jet has tiny primaries and huge secondaries but they are designed to only open on demand. So uit demanding.
If you cut them out, some day you just may need that burst of power to get out of someone's way and regrt not having it.
For instance, I was making a left turn from LaCienega onto Wilshire Blvd one time in my 40 GMC and the light had already turned yellow but I was waiting for the oncomming traffic to show some sign of stopping, well, you know how you can see the front of a car drop when they apply the brakes? They did that, and the light turned red and I went and just then the asshole in the oncoming #1 lane decided to run the red and he punched it. It looked like about a 69 or 70 GTO so he had the umph to come on strong and headed straight at my cab so I was glad I had those huge secondaries to open up and light up the tires and get the hell out of the way in time to not get hit. (400" SBC didn't hurt either)
They put one of them robot red light runner catching cameras on that intersection since then I think.
But some times you'll wish you had the power.
What are you running?
How's it set up, timing etc?

[OldCarPilot]

This is just my daily. Its a 73 Chev Belair 350 with a TH350. Both have 186k miles on them. And even with the secondaries its SLOW! With me in it the car weighs 4650lbs. (and I'm only 155lbs of that) I want to take the secondaries out and drive it a bit to see how it feels. If I feel like it a big difference from a stop I'll probably just deal with the gas bills.

[Deyomatic]

There are two pieces of info he is leaving out.

First, OldCarPilot's definition of "slow" is anything that can't at least turn a mid 13 in the 1/4 mile. This guy is picky! http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

Second, the car REEEEEEEKS of gas just standing next to it, smells like a good gas leak from the carb area. Someone mentioned that the floats on a Q-Jet absorb gas when they get old- making the floats avoid floating and dumping more fuel into the carb. When he took it off the shelf from sitting for about a year, there was no gas smell- at first. After a few days the gas smell came back. I've been trying to convince him to swap out the floats with new ones, but he won't listen to me!

(Sorry, Mike, it's payback for your "right tool for the job" remark!)

[Fat Hack]

Damn, the secondaries on a Q-jet are BIG, for sure...but you can't fit FURNITURE in 'em!

oh wait...you said "inhibit"...not "inhabit".

Nevermind! http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[OldCarPilot]

It doesn't smell of gas as bad as it did. And no... its slow. 17.7 in the 1/4 mile is slow.
Long story short I'm not trying to win any races with the thing, just trying to pick up some mpg. I won't blame the gas smell on the mpg because that holley didn't give me any better milage.

AHotRod,
The arm you are talking about is on the side that the throttle linkage is? Its the arm that goes from that linkage to what is obviously the secondaries? (held on with a spring cotterpin thing)

[Deyomatic]

And that was a Holley 750! Heavy floats are probably going to make it run rich!
Besides, Holleys aren't typically known for their gas mileage.

[OldCarPilot]

Did you get much more than 11mpg with the 2bbl? I never did. All the way to AZ it was 11mpg. At best.

[DrJ]

Take the carb apart and epoxy the leaking pressed-in plugs in the bottom of the float bowl area, below the secondary rods.
make sure the power valve works smooth and lifts the primary rods as it should.
If the primary rods are stuck in the up/power position your mileage will suck.
Put a new float in it.
Dont test it, just replace it.
I prefer brass floats because I can shake them and know if they are leakingbecause they have gas in them if they leaked, the plastic ones just secretly get heavy and sink.
Make sure the dashpot, (That vacuum thingy on the passenger side down in front and below where the fuel pipe goes on) that slows down the opening of the secondary air doors is working.
Pull the hose off and push the rod in and stick your finger over the orifice to see if it holds vacuum.

If you don't have a vacuum advance distributor on it put one on it.
You want the mechanical advance to advance about 24-25º by the time you get to the RPM you usually cruise at.
You want the Vacuum advance to advance about 12º (the newer smog units advance 25º which is too much unless you run the initial advance at 0º.)
Disconnect the vacuum advance and set your timing to a 38º timing mark you made on the dampener at your "all-in" RPM.
That will probably give you around 12-14º initial timing.
Then hook your vacuum advance back up to a Manifold Vaccuum source. SO you will be cruising with 50º advance, great for economy, when you pull a hill or punch it the vaccuum falls off the timing goes back to 38º or less so it doesn't ping on ya.
I get around 20mpg with a Q-jet in my 3000 lb truck.