Quadrajet vs Edelbrock?

Discussion in 'Engine Topic' started by smallblockchev, Jan 23, 2016.

  1. shad_van

    shad_van Veteran Member

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    Jun 15, 2012
    las vegas, NV
    I have ran all 3. I think it depends on your application. no one carb is going to be perfect for every application.

    for ease of tuning I like the Edelbrock Performer/Carter AFB. its very easy to adjust without having to take the whole carb apart by just changing the metering rods. the key to performance with them is adjusting the secondary opening rate. they are pretty good from the factory, but it may not open fast enough for some applications. in which case it is very hard to tune as you have to grind some weight off the secondary air flaps. there is no method to it, just trial and error and if you go to far you can end up with a car that bogs. they also don't like off angles or washboard roads if you are in to 4 wheeling.

    I love the Qjet. it's most difficult to tune compaired a Holley or Edelbrock. But I find it holds a tune better than a Holley. the secondary's are easier to adjust than a Eddy. Plus the small primaries provided excellent throttle response and better mileage compared to a Holley or Eddy if you keep your foot out of the secondarys. if you can find one, Edelborck made some Performer RPM Q-jets that are just plain awesome. I believe the part number was 1910. they are rated at 850 CFM and kick ass when mounted on big block compared to the factory Q-jet. Edelbrock quit making them about 10 years ago. but rebuild kits and tuning kits are still available, if you can find one. I like the edelbrock Q-jet better than factory Q-jets. they don't have the porosity problems that the early Q-jets have. they are made of better materials, and don't warp as bad over time. the standard edelbrock 1901 was for divorced choke and works on 66-73 cars. the 1902 is for 74-78 cars with divorced choke, but is basically the same as the 1901. #1903 is for 75-85 cars with the hot air choke. #1904 is 80-89 cars with electric choke and 1906 is for big block trucks and has triple venturi for better fuel milage on a big block. 1901/1902 are rated at 750 CFM and the 1903/1904/1905 are rated at 795 CFM. and the 1910 is rated at 850. if you decide to go with a Quadrajet, defiantly get the book from Cliff Ruggles. he also sells pars and rebuild kits. his stuff is top notch and not the crap that seems to be at all the auto parts stores.

    I am not a huge Holley fan. you have to take the carb apart to tune them. and they always leak. I have never seen a Holley that has more than a 1000 miles on it that is not leaking around the float bowls or metering blocks. the power valves blow out all the time and they always seem to need a tune up. I ran a pair of 750 double pumpers on tunnel rammed L88 I stuffed in to a Hondo Flat Bottom Drag Boat. That thing wars terrifyingly fast and very loud. it was 105db at idle and deafening full throttle. I got kick off a few lakes because it was to loud. I ended up selling the motor to back to the guy back to the guy who was restoring the corvette it came out of. long story short those double pumpers were the only thing I could find that would not bog out on that boat, but they leaked constantly and always seemed to need a tune up and a new power valves. I just got used to carrying extra power valves and tune up kits any time I took it out.
    Last edited: Jan 24, 2016
  2. 351maverick

    351maverick full time Ebay seller/hustler/car killer

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    Aug 11, 2010
    erie, PA
    ONE good backfire & bye bye Holley power valve

    and they leak

    no thanks

    Edelbrock = no power valve & no gaskets below fuel level = no leaks

    quadrajunk, aka quadrabogs are made of 2000 parts...I took one apart once & 30 springs/clips/balls came flying out like missles
  3. 73 Z

    73 Z Veteran Member Gold Member

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    Jun 9, 2007
    Los Angeles, Ca
    Quadrajet vs Edelbrock?

    I'll use the eddy, more user friendly.
  4. DirtyRob06

    DirtyRob06 Member

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    Jun 15, 2015
    I run a custom built qjet on my car and I love it. Two smaller ports for cruzing around with decent fuel mileage but if you wana put your foot in it. It's got two huge ports on the back so in my opinion best of both worlds as long as it's tuned and jetted correctly. If it was good enough for corvettes back in the day why not lol
  5. marx3

    marx3 Veteran Member

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    Jul 11, 2008
    Denmark, Europe.
    Lots of people are running 10's with a Qjet.
    A Qjet will support 6-700 hp easily.
    Just like any other well tuned carb.
    I prefer Qjet. Edelbrock and Holley are not easier to tune, in my opinion.
    It is a myth that a Qjet is junk and hard to tune.
    If you can take the top off an Edelbrock to change jets/rods, you can do it on a Qjet too.
    Qjets don't have gaskets below the fuel level either.

    If you want to go to work on a carb, to get it tuned for your application, then I strongly suggest going with a Qjet.
    Small primaries : response and mileage like a 500 cfm Holley and the huge secondaries to support 650 hp, if you want it to.
    Easy choice:)
    Call Cliff Ruggles (740) 397-2921
    He will suggest the right jet/rod combo for your carb and engine. With one of his superior kits and possibly his book ( 24.95 ) you have all the parts you need, excluding the carb itself, for 60-70$.
    I am not picking on Holley and Edelbrock. When properly tuned, they are great carbs too.
    Last edited: Jan 24, 2016
  6. 77 cruiser

    77 cruiser Veteran Member

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    Nov 17, 2006
    Frostbite Falls MN
    AFB = A@s

  7. iraqivet

    iraqivet Veteran Member Lifetime Gold Member

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    Nov 7, 2012
    Hobart, Indiana

    Guess I'm selling the Holly's sitting around here!
  8. Marv D

    Marv D Veteran Member Lifetime Gold Member

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    May 12, 1999
    Devils own training ground,,, aka Arizona
    Holley powervalve blowout is most often a owner that doesn't know WTF there talking about (not directing that at anyone here by any means)
    Holleys have had backfire protection for the powervalve since 1992. Yes there are still some 30 and 40 year old carbs out there that don't don't have the checkball, but even in those powervalve takes a HECK of a backfire to rupture. It happens, not saying it didn't with th eancient carbs. But more so this is a internet spread ill of the Holley haters than fact.

    From a HotRod article from 2000 I believe

    The latest advancement in carburetor power valve technology came nearly a decade ago when Holley added power valve blowout protection to its carburetors. This power valve blowout protection system protects the power valve from lean engine backfires that can result from a vacuum leak, old or fouled spark plugs, clogged fuel lines or filters, clogged air cleaner, or ignition problems such as bad plug wires, incorrect timing, or a malfunctioning distributor.

    Even though it is very rare for an engine backfire to rupture a power valve diaphragm, beware. A ruptured power valve diaphragm will cause the power valve to remain open. The likely result will be a rich condition at idle.

    The way Holley decided to protect the power valve from a blowout was to add a check valve system into the throttle body. This check valve is designed with a manifold reference hole and a check ball that will seal the power valve quickly should a backfire occur. Once closed, the check valve system interrupts the pressure wave generated by the backfire, thus protecting the power valve diaphragm.

    The easiest way to tell if your carburetor is equipped with power valve protection is to use a penlight and look through the small hole in the throttle plate. If your carburetor is equipped with power valve protection, you will see a small check ball inside this hole. To help you install power valve protection on an older Holley carb, Holley has introduced a Power Valve Check Ball Kit, PN 125-500.

    It's a $12 kit most places and I'll bet 99% of these old dinosaur carbs that didn't come with the blowout check ball,, have had it added.

    All that said,,, I've ran and raced (or tried to) all 3 carbs. The old Carter AFB was a darn well built unit,, I can not say the same for the Weber version sold as the Edelbroke Performer. I fought 3 of them and their fuel pressure limitation for almost 5 years (before dumping them for something reliable and consistent) It's funny I never had issues with float level / fuel pressure overfilling, and acceleratio pump issues with the Carter AFB,, but ALWAYS fought the Edelbroke,

    The Holleys are a dominant factor on the race track. Go look at ANY serious gas race car and you find EFI or a Holley,, or even Holley EFI. Delivering a consistent 12.8 a/f from launch RPM through the ozone of the RPM scale can only be done with a carb built for it... the Holley 4150 / 4500

    Vacuum secondary carbs like the 3310 are a great compromise between street manors and performance. BUT it is again going to be a serious PITA to set the secondary opening and fuel curve to deliver a precise consistent 12.8 for max power. 'CLOSE' is good enough for street,, but in competition where anything slower than a 0.00x R/T + a loss and run your dial within .01 or .02 or,,, 'close' is only going to put you on th etrailer in the early rounds.

    I've had a lot of GM cars over the years with factory installed Q-jets,, and they always ran and delivered expected economy and performance. I was a Q-jet hater as a carb for a HotRod,, because I obviously had NO IDEA how to properly set them up and make them work on a hot-street application. But then we sent a Carb for my son's 383 El Camino to Sir Damon. (yes our own DAMON) . That is the most responsive, efficient carburator I have EVER had the pleasure of. He gets 18-20MPG on the freeway, and stick your foot in it and it pulls like a MO-fo to 600+ and WAY faster than he needs to be taking a 1967 chassis. (he told me about running with some infinity @ 140+ between Phx and Tuc,, stupid kid!!! I would never do that!!! < grins>)

    Anyways,, rambeling aside. my 2ยข.

    Edelbroke:,, you couldn't GIVE me another one.

    Holley: Made for racing,, the vacuum secondary versions are decent for street.

    Q-jet: MADE FOR THE STREET,, and if set up right,, they deliver decent performance.
    Last edited: Jan 24, 2016
  9. smallblockchev

    smallblockchev Veteran Member

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    Dec 23, 2011
    st michael, mn
    Thanks guys, think i'll be rebuilding the quadrajet.
  10. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    Feb 26, 2004
    Bloomington, MN
    Carburetor Shop in White Bear Lake, IIRC.
    If it needs throttle shaft bushings... They are one of very few places around here which will do it.

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