real life testing a 3310-1 holley vs. 4779 750 dp

Discussion in 'High Performance Modifications' started by 450bench, Aug 15, 2013.

  1. 450bench

    450bench Veteran Member

    2,886
    3
    Feb 25, 2002
    memphis, tn-shelby
    Wanted to test the differences between a good running old Holley 780 vac. sec. and a nice 2 corner Holley 750 dp 4779 that I built...Called a cop buddy with a low 12 second 2007 z06 vette and set up a test race on a local deserted road that we frequent to test stuff...It's a quarter mile so it works well...My set up is a stock body 73 RSLT with a T56 6 speed and a 3.42 gear...The motor is a 9.7 to 1 454 with a custom ground xe274 on a 108 with massively ported and polished 781 heads and a weiand stealth...Jegs headers with flowmasters...Skip White HEI with timing locked at 38...His car, by the way, ran a 12 flat last time out at 115

    With the 3310-1, shifting at 5500, I got him by about a half a car but was pulling him pretty hard...With the 4779, power was way up seat of the pants wise and I got him by an easy car and a half while shifting at the same 5500 to be consistent...We were both shocked that I beat him in the first place but the 454 makes some power and I know the torque was way up with the double pumper as I had serious traction issue in the first 2 gears...One important thing to note too is that all these runs were from a 25 MPH punch.

    We ran several times with each carb, all with similar results...Bottom line is, with a decent set up and combo on a street driven 454 the double pumper is the way to go...Drivability is about the same and idle quality is a bit more consistent with the dp...I never like to over-carb my stuff and it may make more power with an 850 but the throttle response I have is really good and I like that...I can't wait to get it to the track because I think 11.70s or so may be a good number, which is shocking to me with this mild set up and a relatively heavy car

    Just thought I'd pass this along since there are so many vac. sec vs. dp questions on the board

    Carb settings: 3310-1 with milled choke tower, 74s in front 84s in rear...6.5 power valve in front with rear blocked...4779 with choke tower and no choke, 72 in front 81 in rear, 6.5 power valve in front with rear blocked...Vacuum is around 8 inches at 750 rpm
     
    Last edited: Aug 15, 2013
  2. middleagecrisis

    middleagecrisis Veteran Member

    967
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    Oct 22, 2007
    SA, TX
    I've had plenty of Holley VSs and DPs over the years and always felt like I had crisper performance with the double pumpers. Only one of my many carbuerated cars was a manual trans, so I don't buy into the DP for manual trans cars and VS for the automatic equipped cars.
     
  3. 450bench

    450bench Veteran Member

    2,886
    3
    Feb 25, 2002
    memphis, tn-shelby
    Agreed...It's really a total combo thing, I think
     
  4. hhott71

    hhott71 Veteran Member Lifetime Gold Member

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    Mar 30, 2001
    Joplin Mo. 64801
    The 3310, 4779 and 4780 (800 dp) have the same primaries.
    The 3310 has the same size secondaries as the 4780 800 dp.
    The 3310 used to be called a 780, now it's called a 750.

    The 3310, is it tuned to the max as far as accelerator pump shot and diaphragm spring?
    I prefer a DP over a VS even on a stock engine. A 4776 vs an 1850, the DP is the big winner and both use the same size pri and sec bores.
     
  5. 450bench

    450bench Veteran Member

    2,886
    3
    Feb 25, 2002
    memphis, tn-shelby
    Yep, the 3310-1 is a 780 with downlg boosters and is tuned nicely, by me...Bought it new years ago...It runs best on this engine with a 32 squirter and a stock secondary spring with the checkball removed...The 4779-2 likes a 31 and 35 squirter with 2 jet sizes bigger on the front, which are 72s since it came with 70s and 81s in the rear...Gonna open the rear blades a bit to help with mixture screws
     
  6. Bumpad_Z28

    Bumpad_Z28 Veteran Member

    500
    2
    Apr 9, 2004
    Logan, UT
    I have and had planned on using my carb shop modified 3310 on my '78, BUT have been on the lookout for a good 4779 core for awhile ! This thread makes my looking more serious, interesting results ;)

    ~DaVe
     
    Last edited: Aug 15, 2013
  7. hhott71

    hhott71 Veteran Member Lifetime Gold Member

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    Mar 30, 2001
    Joplin Mo. 64801
    ebay and craigslist or our local dragstrip forum, it's a great swapmeet site.
     
  8. newschool72

    newschool72 Veteran Member

    1,177
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    Feb 25, 2011
    forsyth,ga
    Ive never understood why anyone would use a vac sec carb on anything but a stock driver. To be honest, I would have thought there would be more difference than you saw. It sure feels like two different worlds to compare the two. Nice test by the way. Racing a cop on a deserted back road sound like the makings for a new car movie, LOL.
     
  9. bige

    bige Veteran Member

    167
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    Oct 21, 2010
    Cincinnati, Ohio
    When my 383 was being dyno'ed the builder tryed several different carbs including vac. and mech. secondaries and the Holley Model 4150 HP Carburetors 0-80529-1 with vacuum secondaries made the most powr (497) and had the smoothest power curve. Am I missing something?
     
  10. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

    8,699
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    Sep 20, 2004
    Southern Maryland
    No one will ever agree on "the best" carb because there really isn't one. They are just all different.
     

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