Two QJ's into one

[F250 Restorer]

I was running a 17059272 on a hp Ford 300.  I wanted the smaller primaries, and a richer idle circuit, so I switched the main body to that of a 17058504.  I used Cliff's inserts for smaller main air bleeds, and Cliff's idle tubes.  Since I used the air horn from the 272, I kept the main air bleeds there at the oem size.  No by pass air.  I set the APT to 2 1/2, but will do the tip in when I have more time.  I used 72 main jets and C's 44 m.rods. 

It fired right up.  I'm still surprised how smooth it idles.  I was a bit surprised to find the mix screws set at only 1/2 turn out.  No more hesitation, and better throttle response. 

Thanks for the help, Cliff.

[Cliff Ruggles]

Nice thing about those later carbs, the throttle bodies and airhorns will swap as long as both were the 4 MAB models.  The idle bleeds aren't the same between those units.  The smaller main bores will increase velocity of the incoming air, not a bad thing for a small CID engine.  The 300 in line 6 pulls pretty hard on the carb anyhow, and wouldn't need a large cfm carb right to start with, so no power would be lost going to the smaller casting.....Cliff

[F250 Restorer]

Cliff, I was wondering why once in a while, fully warm, after driving 20 minutes or so, it wants to run on.  I have the idle at 750 in park.  I haven't done the tip in yet. 

[Cliff Ruggles]

"Running on" is either idle speed too fast, or not enough timing at idle, or both.  Retarded initial timing puts the throttle plates open further, and makes it easier for the engine to want to "run on" after shut down.....Cliff

[F250 Restorer]

Rule of thumb as a kid was always 'advance it 'till it pings, then bump it back a tad.'  When I had my dizzy recurved, the tech said to set the initial at 16*.  I did, but the starter kicked a bit.  I will advance it slightly. 

I was thinking of bending the acc.pump arm slightly to lessen the squirt, while trying to improve mpg.  Outside setting was too little.  Any suggestions.

I want to change the cross-drilled s.nozzles.  Do I simply heat housing and pull?

Any experience using a Lokar cable for a kick-down?

Thank you. k

[Shark Racer]

FWIW, the only way to really set your advance curve is with some kind of performance metric. If it's pinging you've certainly gone too far, but you can go too far without pinging as well.

Bending the pump arm is one way to change shot, you could also move it to the outside setting and shorten the pump shaft I believe. Cliff knows the answer to that one and I believe you can find info on the forum via search (don't want to be that guy, I just know I've seen it on here before)

[Cliff Ruggles]

We have longer pumps, and also a .100 longer pump arm to reduce pump shot.  Either way accomplishes the same thing.

The easiest way to pull the nozzles is to insert a punch that just fits them, and apply outward pressure 360 degrees.  Do a couple of circles and they will fall right out........Cliff

[F250 Restorer]

It is rare a customer finds a business like Cliff's.  He has helped me by answering untold posts, always offering the best advise and guidance. 

By following his advice about v.advance being a major player in mpg, I solved another issue and increased my mpg. 

I have to admit that the QJ intimidated me when I first started working on it.  But now I've grown very found of it for performance and mpg. 

[Cliff Ruggles]

They do work flawlessly and as good as any fuel injection set-up, once you get them dialed in exactly for the application.  With the in line 6, it's not a common set-up, so may take longer to nail down the tune, but the end result will be a nice running engine, and great fuel economy.

I've been up in the mid-20 MPG range with several cars I've owned that were Q-jet equipped.  Nailed down 29mpgs on my 84 Impala, and 25mpgs on the 67 Impala SS that I used to own.  Not to mention dead solid reliability the entire time I owned them......Cliff

[F250 Restorer]

Cliff--

I was adjusting the point where the v.advance comes in, in an effort to add some more mpg.  I changed it from 900 rpm to about 1600 rpm.  Is that moving it in the correct direction? 

[Cliff Ruggles]

At light throttle openings and light engine load the vacuum advance will be fully applied, so it will be adding all the timing from the unit for best MPG's......Cliff

[F250 Restorer]

I was amazed by my results.  I've been monitoring my fuel consumption closely after doing Cliff's tip in method for the APT tuning.  It stayed the same for 4 tanks.  Then I thought I would richen up the mix and see if I got better power.  I turned the APT 180* counter clock wise, moving the m.rods up out of the jets slightly.  I was quite surprised to find that I drove 20 less miles on ten gallons of gas than before.  Ten miles less per 90*.  That is how sensitive the adjustment is!

[Cliff Ruggles]

Absolutely.  Those metering rods have a slight taper on the upper section, from .044" down to about .042", then quickly on down to the .026" tips.  You will find a point in the adjustment range where very small movements of the APT screw will have a MAJOR impact on fuel delivery......Cliff