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I've decided to run an 850 cfm Quick Fuel Carburetor on my 496 build.
Holley Tech Services recommended their Quick Fuel Street SQ-850, which has cast aluminum fuel blocks and a cast aluminum base plate, for $548.95.
They also offer the Quick Fuel Q-850, which has billet aluminum fuel blocks and a billet aluminum base plate for $772.00.
Both carburetors have no choke, mechanical secondaries, vacuum ports and the same internals.
Holley Tech Services said the billet carburetor is better quality, but doesn't offer any performance gains and said that the Quick Fuel Street SQ-850 is still better quality than their Holley HP series carburetors.
For those who run the Quick Fuel carburetors, is it worth spending the additional cost for the billet fuel blocks and base plates?
Why?
Thanks, Greg
Last edited by OldCarBum; Mar 22, 2018 at 11:16 AM.
without going into the long story. Lots of cast carb venturi bodies are not 100% equal in dimensions. Some of them are so poor in even positioning the boosters that you can see that they are off whack compared to the center of the bore
so you end up having to spend hundreds of dollars in machine work to correct all the poor workmanship. So all these after market companies make sure that it is right out of the box. Bigger bowls with sight glasses, better floats, quality large diameter needle and seats, correct diameter idle circuits, drilled throttle blades
the list goes on of everything you have to fix on on Holley and the crap model year Demon carbs .
I have one cheap bastard friend that went with me in my RV. I prior to the trip bought all nice steaks. ...... when he saw the grocery shopping bill "He tells me that I spent to much on the steaks etc! " He tells me that the $4.99 round steaks from walmart are just as good, but he is a bottom feeder and doesn't go with me any more.
Quickfuel makes excellent Carbs.. I ve had their 750 DP for 9 years now.. zero issues .. does not need constant adjusting . turn the key and go .. what are you putting it on ?
Quickfuel makes excellent Carbs.. I ve had their 750 DP for 9 years now.. zero issues .. does not need constant adjusting . turn the key and go .. what are you putting it on ?
It's going on my 496 build.
Do you have the cast or billet blocks and base plate?
Last edited by OldCarBum; Mar 22, 2018 at 02:06 PM.
They are both excellent products. You can not go wrong with either.
They both have the exact same calibration, so it really comes down to if you want to spend the extra $200 for the billet metering blocks and base plate.
Will
They are both excellent products. You can not go wrong with either.
They both have the exact same calibration, so it really comes down to if you want to spend the extra $200 for the billet metering blocks and base plate.
Will
I've run Holley carbs for decades.
Q-jets and Rochester are all cast components as well.
I was hoping someone would step up and say the billet is better and this is why so I could determine if the additional cost is justified.
GKULL is correct and I believe in what he says, that's why I'm going with Quick Fuel in the first place.
It's kind of like the question of, " Do I need a forged crank or will a cast crank support my build"?
Even though I really didn't need it I went forged crank.
I'll wait and see regarding billet or cast.
Thanks.
Last edited by OldCarBum; Mar 22, 2018 at 02:12 PM.
The billet blocks are probably more adjustable. The website says they offer changeable idle feed and power valve channel restrictions. That would offer more tuneability of the carb. The cast block would just have sized holes drilled in them and offer no tuneablity.
Let me also add the billet baseplate does not have the notches for a factory style throttle cable bracket.
Last edited by Sigforty; Mar 22, 2018 at 02:25 PM.
I was having a hell of a time getting enough air for a good idle because I had to open the primary's too far. Made for a crappy off idle drive. I reset the slot to spec and used the rear opening to get the idle I wanted. Now it comes off idle easy.
The billet blocks are probably more adjustable. The website says they offer changeable idle feed and power valve channel restrictions. That would offer more tuneability of the carb. The cast block would just have sized holes drilled in them and offer no tuneablity.
Let me also add the billet baseplate does not have the notches for a factory style throttle cable bracket.
Thanks, I was not planning to run the stock throttle cable bracket.
I was having a hell of a time getting enough air for a good idle because I had to open the primary's too far. Made for a crappy off idle drive. I reset the slot to spec and used the rear opening to get the idle I wanted. Now it comes off idle easy.
Thanks for the article.
I've been around billet and cast parts for a long time.
I always prefer billet but on something like a base plate or fuel block I am wondering if the parts are the same and only the material is different or if there is a specific difference in the parts themselves as you mention in your later post.
Thanks again.
Everyone is helping me to spend more and more money.
My vote is for the billet build Q 850 . I have been running mine on my little 355 cu in for the last two years now . Will not say it runs better than my old Holley but is nicer to fine tune . Also has the secondary adjustment on all ready no need to buy .
My vote is for the billet build Q 850 . I have been running mine on my little 355 cu in for the last two years now . Will not say it runs better than my old Holley but is nicer to fine tune . Also has the secondary adjustment on all ready no need to buy .
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Billet or cast?
