Hello Quick Fuel, Goodbye Holley

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Ironmike

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Well, my QF came today. Plan to bolt it on tomorrow.....have to cut down the vent tubes a bit to clear my low air cleaner, but other than that, gonna try it out of the box.

man, that HP 950 runs so damn good, but been instructed by my Jedi Master that it just aint quite enough. Leaving power on the table. Also the annular boosters are supposed to work way better than downlegs, with an intake like my Super Victor.

FYI, I'm running the Holley with 75 primary and secondary, with power valves front and rear. Hope the QF jetting is close.......

Holley HP 950 flows somewhere in the 780 CFM range. The QF, a true 950 CFM. So ive been told.

Let you guys know results!
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What do you mean by results,have you ever had the motor on the dyno or the car to the track to get a baseline? Are you planning on doing this? My motor on the dyno only used 630 cfm or air, so i have an AED 750 HOM which flows 830, more than enough carb for my application. My engine builder always said give the motor what it wants, not what you think it needs. Best quote ever.
 
Ironmike said:
Well, my QF came today. Plan to bolt it on tomorrow.....have to cut down the vent tubes a bit to clear my low air cleaner, but other than that, gonna try it out of the box.

man, that HP 950 runs so damn good, but been instructed by my Jedi Master that it just aint quite enough. Leaving power on the table. Also the annular boosters are supposed to work way better than downlegs, with an intake like my Super Victor.

FYI, I'm running the Holley with 75 primary and secondary, with power valves front and rear. Hope the QF jetting is close.......

Holley HP 950 flows somewhere in the 780 CFM range. The QF, a true 950 CFM. So ive been told.

Let you guys know results!View attachment 1714949368 View attachment 1714949369 View attachment 1714949370 View attachment 1714949371 View attachment 1714949372 View attachment 1714949374
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I hope you get the desired results you want, by the way it sure looks purdy:thumbsup:
 
414 ,11 to 1, cnc ported Indy/RHS. Flowed 292 at .600, if I remember. Lackluster exhaust ports, though. Intake vacuum on the dyno said she wants more. Or should I say, can handle more...Extensive dyno time. Believe me, my guy knows his crap after 40 years in the business and racing. He did not build the motor or design it, just the machine work and dyno. No reason to lead me astray. Nobody will ever build my motors but me again. Been there done that.

Haven't been to the track this year, yet. Won't happen til August. Like I said, it runs good. Real good. But no sense leaving easy power on the table.

Made a few bucks selling stuff here and Racingjunk.com, so I consider the carb a free upgrade. Ah...don't tell my wife, though.
 
I dumped my Holley years ago and bought the exact same carb. I have been very happy with it. You can buy a full set of air correction jets from summit if needed. Good luck! Andrew
 
Do you have any way to check the afr's? My experiences with qf carbs have found they are pig rich at cruise.
 
justinp61 said:
Do you have any way to check the afr's? My experiences with qf carbs have found they are pig rich at cruise.
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Just my plugs, brutha. Glad you mentioned this. Gonna have to look for this. Rich at cruise and good at WOT is a problem. Air bleeds?
 
See the quick fuel decal on the side of the carb...peek behind and see what it says.....I accidently removed it...and there is another name on my main body....
 
If it ain't broke DON'T FIX IT, IDIOT!

Put on the QF today and first problem is, the "throw" from idle to WOT must be a bit longer than my Holley, cause I had to really fart around to get my stock type cable to work. Still ain't quite right.

Second....just can't get rid of a slight hesitation off idle. Just like you get when maybe your squirter isn't big enough. Except that ain't it.
Basically it's piss poor throttle response for the first 25 percent of throttle. WOT seems ok.....
Noticed a small popping from tailpipes going downhill, no throttle.

I noticed my tried and true Holley has 2, 1/8 inch holes in the primary blades and 2 in the rear as supplied by an engine builder 6 years ago. Maybe I should drill the QF. Or maybe see if Summit will take back a carb that's had fuel in it.

I just couldn't leave well enough alone. Stupid...
 
Does your quick fuel have a secondary opening screw? Thats the alternative to drilling the throttle blades on the secondary side. We sent a quick fuel carb back to local supplier here after it had fuel in it, no problems there.
 
Oh yeah, it's got a secondary adjustment. The carb is waaay off, man. Gonna mess with it today and see if I can get it close. I think before drilling the throttle blades I'll just send the friggin thing back.
Frustrating.
 
Well, spent the afternoon in sheer frustration.

Changed the idle air bleeds from 73 to the 78's that were in my Holley. Went from 33 squirters to 31.

Got it idling real nice, pulling 12 inches vacuum at 1200 RPM........just like always.

Off idle stumble better but still there and I just can't get rid of it. My last resort tomorrow is jetting. I think it's rich. Turns out I was running 74'S in my Holley, this has 78's.

Can rich mains cause an off idle stumble?
 
love em or hate em.holley is a tried and true carb.i personally like them.my 750 hp was real close right out of the box.send it back if your having that much trouble with it
 
Ironmike said:
Well, spent the afternoon in sheer frustration.

Changed the idle air bleeds from 73 to the 78's that were in my Holley. Went from 33 squirters to 31.

Got it idling real nice, pulling 12 inches vacuum at 1200 RPM........just like always.

Off idle stumble better but still there and I just can't get rid of it. My last resort tomorrow is jetting. I think it's rich. Turns out I was running 74'S in my Holley, this has 78's.

Can rich mains cause an off idle stumble?
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Off idle stumble it typically in the pump shot CCT. On the street i just increase squirter 2 sizes at a time go out and nail it till it blows black out the back then go back two sizes.
 
Try 50 CC accelerator pumps? haas worked in the past, all combo related. Have to keep trying **** till something works. At the track we would jet up till the mph fell off. then go back 2 sizes, increase squirter till you got best 60 foot.
 
Just out of curiosity, how much initial timing are you running? If you have a 35 nozzle you may want to try it on the primary side. How many turns are the idle mixture screws out?
 
jdsduster said:
love em or hate em.holley is a tried and true carb.i personally like them.my 750 hp was real close right out of the box.send it back if your having that much trouble with it
Click to expand...

Quick fuel carbs are essentially Holleys.
 
A Holley 950 flows 780? WTH? I thouoght the 750 4150's flowed 780, and the 850 had the larger 1.75 bores and then the 950 had....Man, thats just false advertising.....
 
850 flows more than the HP 950. Read it many places.....

Distrib locked out, my engine wants 30 degrees. I know it sounds low, but the dyno proved it. 110CL cam installed at 104 may have something to do with the 30 degree thing. Anyhow the bigger idle air bleeds got my mixture screws to 1 1/4 turns. Yesterday 3/4 turns and was way worse, stumble-wise.

Man, 35 squirter seems big. Ran 32 in my 950..

Man, this thing was spot on 3 days ago.....I fell pray to the QF thing. Leaving a few ponies on the table might not be so bad a thing when your combo is running balls out the way it is. Friggin thing made 562 and I got caught up trying to pinch a few more out.

Gonna play around with it tomorrow and if I can't get it ironed out back on goes my tried and true 950. Not worth the aggravation at this point. Summit will take the damn thing back if need be.
Oh, yeah. I think this carb HAS 50 cc pumps. If not, it wouldn't help anyhow. The stumble comes before the shot is over. Like I said, just off idle.
 
I gave up. Put the Holley back on today. Took a quick blast to remind myself how good it ran BEFORE I got the QF bug.

Far as the QF stumble, it's definitely AIR. It wants more air just off idle. I tried everything I could do and was unsuccessful. With the secondaries adjusted almost closed, it literally dies when ya blip the throttle. Open up secondaries as far as feasable and it stumbles. Pretty obvious it wants more air........I think.
My Holley came from factory with 4 holes in the butterflies. This gotta have something to do with it.

Trying to decide if this is all worth 8 or 900 bucks, and get a hold of Thumperdart, or just return the damn thing.
 
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