View Full Version : Carburetor choice, QF or Holley
slpro1207
11-11-2017, 03:25 PM
I am curious as to the difference and preferences of the Holley 750 double pump versus a comparable Quick Fuel. From what I can tell there is little to no price difference. What is everyone running on their carbureted roadsters.
GoDadGo
11-11-2017, 03:38 PM
I suspect that the Quick Fuel Carburetors will win big in head to head popularity so it will be interesting to see the results of your poll.
Also, I was having some very good luck with the Edelbrock AVS 800 prior to my engine block debacle.
Go Karting With Wife Had Good Drivability:
https://youtu.be/yL4UmpII9ek
Little 1st Gear Roll On Gave Great Acceleration:
https://youtu.be/PCngiKoopkA
edwardb
11-11-2017, 03:59 PM
I've been very happy with the two Q-F double pumpers I've used. They were vastly superior to the single Holley I've had. But to be fair, that was an entry level vacuum secondary carb that I never could get to set up and run well. Q-F's are a very similar design as Holley, in fact some parts are interchangeable. But they were sold as upgrades to the Holley style product. Including such features as built-in sight glasses, machined aluminum parts vs. castings, interchangeable jets, bleeds, etc. in places were it was necessary to drill to adjust a Holley. There are now premium Holley's that are probably on par with the Q-F's. Plus the situation is a little more muddled I guess since Q-F is now part of the Holley Corporation. But I would still highly recommend Q-F. I specifically used the SS-650 and SS-750-AN which has the annular boosters.
Can't go wrong with either. The QF has more adjustability with screw in vs. drill to size on some of the circuits but I suspect most back yard mechanics won't even know how to use this feature. I use a Holley but it is outfitted with QF metering blocks with all the screw in features that make tuning easier. The 4150 style QF is a clone of the Holley Double Pumper so gaskets, jets, and other items are interchangeable. Unless you know how to really tune a carb you probably should make the selection between the two based on price.
Jsf74
11-12-2017, 07:18 AM
Well holley owns qf now so they are now one in the same. Roll the dice.
Jim1855
11-12-2017, 08:30 AM
As JSF74 mentions Holley owns both but the Holley line-up includes many more varieties from a simple street versions to the HP series. Adjustments and options range from none to everything. I have not worked with the QuickFuel products.
I'm currently running a fully adjustable Holley HP based carb tuned by ProSystems and have been quite pleased. But then I may switch to a latest Holley, either the 750 or 850 Ultra HP series. I've heard good things about these.
https://www.holley.com/products/fuel_systems/carburetors/ultra_xp/
slpro1207, it seems that you've selected the size (750). Just in case, there are many good sizing tools on-line. Are you planning a choke, then manual or electric? Do you need all of the adjustment? Often improper mods or tuning detract from drivability or overall power.
Jim
CraigS
11-13-2017, 06:39 AM
4- yrs ago when I bought my QF, I picked it because it had a lot more replaceable jets than most. Especially carbs w/ a choke. Some Holleys had them but they were race versions w/o chokes. I have found that we spend a LOT more time driving on the idle circuit than I ever realized so having both idle feed and idle air bleeds replaceable can make a big difference.
first time builder
11-13-2017, 09:01 AM
From the experence of using a "worked" Holley to a QF with only a Power valve change the QF out performed the Holley. Most tuners will replace Holley power valves with QF.
Kenny
Frank Messina
11-15-2017, 04:17 PM
I'm running a Holley HP 750 and very happy with the performance. I did change idle air bleeds as well as the main air bleeds and jetting to dial it in but the engine responded with every change. Drivability and throttle response is outstanding. IMHO the adjustability afforded in a Holley HP carb is all one needs in 98% of the cases. If one starts tinkering with other circuits you're not educated in you stand a good chance of "losing the rabbit" and introducing new problems. This is just my personal opinion on the subject but being able to adjust every circuit is simply not for everyone and not required for street driven vehicles.
wallace18
11-15-2017, 04:42 PM
QF all the way!
Avalanche325
11-16-2017, 12:25 PM
I am also a QF fan. I was so disappointed when Holley bought them. Holley made a good product, but since they were pretty much the only mainstream carb guys they sat on their rumps, stopped development, and sold the same old stuff. QF took the carbs to the next level. That also woke Holley up, as they had to compete. I hope the lack of competition doesn't make them complacent again.
GFX2043mtu
11-16-2017, 10:33 PM
Quick fuel all the way. It’s a better more tunable carb with several of the Holley carb issues taken care of out of the box. The only reason I would use a Holley carb is if I had one sitting around and the only cost was upgrading it with some of the QF parts. For a performance carb Quick Fuel is hard to beat. If you want a super simple street carb that any one can tune to run well on a modest engine and don’t plan on squeezing every ounce of performance from the engine a Edelbrok is a good choice too.
Mesa Mike
11-17-2017, 02:49 PM
I'm a Holly guy. Trust them. Use them.