850 Edelbrock setup

Discussion in 'The Venerable Q-Jet' started by sailbrd, Mar 11, 2005.

  1. sailbrd

    sailbrd Well-Known Member

    Anyone have experience setting the Edelbrock 1910 850's up? I have a 10:1 motor with a TA 413 and a nice set of heads. I got a real nice 850 with the tuning kit from a member here. Looking forward to a total rebuild of the fuel system this year (new motor would suck the old carb dry as I hit 5500 rpm.)
     
  2. BUICK528

    BUICK528 Big Red

    I have the same carb, same cam and Stage 2 heads..

    Jim
     
  3. 70gsrick

    70gsrick 1 of 66

    I have the same carb....No problem with starving but it has a nasty bog going into the secondaries..I guess it's opening too fast.
     
  4. RAbarrett

    RAbarrett Well-Known Member

    The starvation issues will require some investigation. I need to know whether the bowl is emptying out, or whether the metering is the issue. With respect to the bogging, there are several things that can cause that. To begin with, the Qjet is metered for the use of the hot air air cleaner. If the air cleaner does not provide hot air,but rather the cold air used for maximum power, the metering will require changing for the cold air density. It will require additional fuel for the additional air density. There are issues with the secondary air valves that can cause a bog as well. To begin with, it is possible that the secondaries are opening too early, or too quickly. Check two things; the first being the front choke pull off, which is vacuum controlled. If this pull-off is defective, there will be little control of the air valves, causing an opening and slamming shut. The valves need to open progressively, meaning slowly. Their opening rate is tunable, using the screw on the passenger side of the rear of the carb. Let me know if this requires some clarification. Another system is the secondary accelerator pump, which everyone thinks is a Holley exclusive. The double pumper system is actually better executed on the Qjet. This system is not operated by a diaphragm, but rather by air movement. This system is based on the venturi concept. Looking at the secondary barrels, on both sides, there are small holes either above or below the secondary air valves front most surfaces. The very high performance Qjets have these holes below the air valves, making them slightly more sensitive to air flow, but the concept is the same with both systems. The idea is that, as the air valves open, there is a very intense air flow at their leading edges, which, if the tubes are open, will pull extra fuel from the bow. As they open further, the venturi effect is lessened, and the tubes stop feeding. If these tubes are blocked even slightly, the resulting loss of fuel flow can cause a bog exactly like the hesitation caused by a defective accelerator pump on the primary side. Let me know... Ray
     
  5. 70 gsconvt

    70 gsconvt Silver Level contributor

    I recently got one of these carbs for my car. I'll probably be switching to a Gessler-prepped Performer intake and 1910 carb. Hopefully I won't lose any performance in the quarter mile.

    My Desktop Dyno says I'll actually be almost one tenth quicker because of more torque at lower rpm's.
     
  6. sailbrd

    sailbrd Well-Known Member

    Thanks for the comments. Just to clarify I have not used this (the 850) carb yet. My old 800 q-jet was running outing of fuel.

    Plans for the new fuel system.
    Stage 1: Sump the tank, run new 1/2 inch to the mechanical fuel pump. Run -8 AN to the carb.

    Stage 2: Off the second line from the sump go 1/2 inch to a Holly Blue pump. From the electric go -8 AN to a "t" with the -8 line from the mechanical pump (line from mechanical has a check vavle.) -8 AN to pressure regulator, -8 AN to carb. This will leave another line off the regulator for future NOS system.

    Since I have the big tuning kit I should be able to dial the carb in. I do remember that JW said he ran one of the 850's stock and came real close to a 950 HP.

    Let me know what you think.
     

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