QFT-1050 help

[prairiehotrodder]

I'm helping my friend with his 423 SBC and i have carb apart. Its a Q-1050 gas carb and its always been very rich. The factory jets are 86/93 with a 4.5 PV and a 28 HSAB.

I just took it apart to look at the emulsion jets. Seems weird to me but from the top down there are no jet, no jet, jet, no jet.

IMG_1057.JPG

same on front and back but with PV plug in the back.

[PRH]

Actually, I think you’ll find it’s the other way around.

It’s: open/open/plugged/open

If that’s a downleg booster version, I ran one on a hot street 572” BBM.
We ran 85/91 jets in it, and the A/F ratio was in the mid-low 13’s.

I’d just do the easiest thing first...... take some jet out.

[steve cowan]

I did some mods on a 1350 a while back and it had from memory
Blocked
28
Blocked
28
28
I also moved IFR to lower position and fitted transfer slot jet to main body
Went to power valve front and rear 10.5 on both plus fitted PVRC in rear block.
632 BBC makes around 850hp pump gas streeter.

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[PRH]

It might be a good idea to make sure there are actually emulsion holes at the “bottom” of the threaded holes.

[prairiehotrodder]

thanks guys. I think i might be becoming overly worried about this carb when its not likely a problem. after looking closer i see PRH was correct on the emulsion setup. We had the main jets at 84/91 which really isn't far off the factory calibration. I moved it to 82/91 and we'll see what happens with the new 5.14 gears. I have a new 850 i'll try on the car if the 1050 seems to be a problem. I just can't get past the thought that this car seems like its missing 100 hp.

[BradH]

It might be a good idea to make sure there are actually emulsion holes at the “bottom” of the threaded holes.

The 4-emulsion QFT/Proform "race" metering blocks are supposed to have pre-drilled .028" emulsion bleeds in all 4, and from the factory they only plug #3. I've had two sets of these blocks to check out, and one was "right" while the other wasn't drilled consistently at all. The "wrong" set I ended up drilling out the pre-drilled holes to approx..050" and using 6-32 set screws drilled to .028" on #1 & #3, and blocking #2 & #4. Nothing fancy, just functional.

[1980RS]

The 2 quick fuel carbs I acquired over the year sit on the shelf. Way to much work for something the should be a lot closer calibrated out of the box. I had a QF 750 Slayer carb and out of the bot it was super pig rich and you could not adjust it to save your life. I called QF and asked about this, his reply< "lean is mean so we run them richer" that told me the tech guy was an idiot. I swap carbs all the time with people buy when they offer a QF up to trad I just pass on them.

[1972ho]

Any of you guys with the problem QF carburetor on the shelf just pitch them my way, lets deal.

[1972ho]

Pratiehotrodder if those emulation that are open to the well don’t have a blank in them you putting an awful lot of fuel to it and almost no emulation air so it should be rich

[BradH]

Pratiehotrodder if those emulation that are open to the well don’t have a blank in them you putting an awful lot of fuel to it and almost no emulation air so it should be rich

That style of metering block isn't drilled the diameter of the e-bleed all the way through; it's only a little farther than where it's threaded. The end of the hole is still closed, other than where the standard-size bleed hole is drilled.

Also, your response sounds inverted to me, in that if all those holes were drilled 6-32 into the main well, there would an overabundance of air, not fuel, and it would go seriously lean.

[stealth]

Where is it rich?

Idle
Cruise
Wide open

[prairiehotrodder]

Holley finally got back to me and told me what emulsion jets i'm supposed to have from top to bottom : 28 blank 28 28.
As you can see from the picture i had empty empty blank empty.

Hopefully once i get the emulsion jets put back then i should be able to go back to the factory jetting and start tuning over again.

Brian

[PRH]

I believe the empty holes are “supposed to” have a .028” hole at the base.

You should pin them and see what they are........ and/or drill them out bigger and install the brass restrictors in the sizes you prefer(as Brad said he did on a set of those blocks).

If they are in fact .028, all you’d have to do is move the plug up a hole to end up with Holleys recommendation.