Manual Choke to Edelbrock 4bl Carb?

Discussion in '40- & 55-Series Tech' started by ARC1, Aug 9, 2009.

  1. ARC1

    ARC1

    Messages:
    585
    Location:
    Orange County, CA
    This is probably a super-basic question only a newb would ask..

    Today, I removed my Edelbrock 4-barrel carb to clean and spray it out, as my 327 SBC is not running due to fuel issues. I'm also replacing some filters, and hopefully won't have to replace the fuel pump. While removing the carb, I noticed, that either this choke cable had sprung loose, or was never connected!?
    [​IMG]

    Now, I have no idea how it connects to the carb. Can someone point out exactly where and how I should be reconnecting this choke cable to the carb? For ID reference, the stampings on my Edelbrock carb are:
    1406 3115 (on front), on top back, there is "8867"
    [​IMG]
    - what is the black circular thing with the 2 wires? Hidden by the wires, there is a counter-clockwise arrow -> "LEAN" and the 2 wires are (+) and (-) obviously. Is this some kind of automatic choke?
    [​IMG]
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    Thank you!:beer::beer::beer:
  2. Mark W

    Mark W

    Messages:
    6,171
    Location:
    The Greatland
    It is not connected because that model Edelbrock has an electric choke. that is the black circular unit with the wires. the 1405 is the same carb w/manual choke. If you want manual, you can disconnect the rod from the electric choke at the tab on the side of the carb and connect your cable there. You will have to fab a bracket to hold the cable though. Edelbrock *might* sell you the bracket itself... maybe.


    Mark...
    Last edited: Aug 9, 2009
  3. inkpot

    inkpot SILVER Star

    Messages:
    8,473
    Location:
    Chandler, Az.
    Howdy! I have the same carb with the electric choke. Works fine. Use the manual choke cable as a hand throttle. John
  4. cmiller114

    cmiller114

    Messages:
    298
    Location:
    Enola, PA.
    2X.....a couple of observations. Throttle cable is too long/too bent, it's going to bind and stick. Fuel line laying on valve cover is not a good setup, too hot.
  5. ARC1

    ARC1

    Messages:
    585
    Location:
    Orange County, CA
    Thanks for the tips..
    My throttle does stick. I was going to shorten it a bit, and squirt some silicone lubricant down the line.

    I was thinking there might be some other choke. :whoops:
    I guess all that pushing & pulling the choke while trying to get my rig started wasn't helping much, huh? :lol:
    - what model Edelbrock carb is this? Performer? I can't find a google site to plug in the numbers. Just curious..
    - am I missing something obvious? or is it always such a PITA to scrape off this gasket? I'm using a straight razor and some carb cleaner to moisten.:bang:
    - any tips on adjusting the carb? (assuming I get it reinstalled, and she starts) I have some general steps, but looks like I need to get a handheld tach meter.

    Ok, as always.. thanks! :cheers:
  6. RMC73FJ40

    RMC73FJ40

    Messages:
    149
    Location:
    Lawrenceville, GA
  7. ken_79-fj40

    ken_79-fj40

    Messages:
    1,261
    Location:
    New Hampshire
    It also looks like that is actually your heater valve cable too. That's where mine comes out of the firewall, just had it off the other day.
  8. inkpot

    inkpot SILVER Star

    Messages:
    8,473
    Location:
    Chandler, Az.
    Yup, I think it is too, now that you mention it. Pull the fuel line off at the carb and see if it flows good into a coffee can when the starter is operated. If not, the it is probably blocked filter, bad pump, or blockage in the tank. It it flows good, then open the top of the carb and check/set the float properly. You can buy the Edelbrock book for about $20, and that will show you how to do it all. John
  9. There are manual choke conversion kits that include a plastic cap with a lever that replaces the black cap with the wires in your photos. The trick to these kits is to make sure the caps that included are of the same diameter as the cap they are replacing. Sometimes they are not, and the fit will be loose, causing the cap to eventually fall off. Be aware that there is a vacuum port on the electric choke models that must be plugged when converting to manual choke. (Going the other way, from manual choke to electric choke, Edelbrock says this is not possible because of the lack of the vacuum port on the manual choke models.) The proper way to seal up port openings that won't accept a nipple is to jam a small lead ball into them. This allows the ball to be removed with a drill bit and a screw. Epoxy is "forever".

    Aside from the idle screws, there are other mixture adjustments on the Edelbrock. On the right and left side of the air cleaner threaded rod, there are two little sheetmetal covers held on by screws. Under these are metering rods. These metering rods, and the jet they insert into, can be changed to alter the cruise mixture. You have to be very careful when changing rids not to allow a screw to fall into the intake manifold. But you don't have to take the carb apart to do minor mixture changes, unlike a Holley. Edelbrock sells kits with extra rods and jets for tuning.

    I asked the Edelbrock rep whether there were differences between the manual and electric choke versions of their carbs. He confirmed what I suspected. The manual choke carbs are set up for more power, while the electric choke models are set up for more fuel economy. (Their website now clearly lists the jet and rod size - it didn't at the time I inquired.) The difference is subtle, but the metering rod tables bear this out. What this means is if you are looking for economy, you're better off getting the electric choke model. Otherwise you'd have to get the rod and jet tuning kit for the manual choke model. If you have a "built" engine, the electric choke model may be on the lean side for a healthy cam, headers, etc. You might want to "fatten" up the mixture a bit by installing rods and jets for a bit more fuel.

    And note that, unlike a Holley, the rods and jets on the Edelbrock are more than just a simple flow orifice. Because the rods are tapered, they control fuel flow at various throttle positions, depending on how far off of their normal idle position they are lifted. At idle, the rods cut down on fuel flow because they are larger in diameter. As they lift, they taper, increasing the area for fuel to flow. There is a chart with the tuning kit that shows this. It is possible to have more than one combination of jets and rods that will flow a certain amount of fuel at WOT (Wide Open Throttle), allowing you to pick a set that will flow more or less at off idle and cruise. These carbs are much more tunable than a Holley, but they are much less understood than a Holley, and seem baffling to most people. They are often maligned for not being economical to run, but, the people maligning them overwhelmingly run them out of the box and never attempt to tune them by replacing the rods and jets.

    The other adjustment is the accelerator pump setting. That's the long curved lever on the driver's front side of the carb. There are three hole positions to chose from.

    The Thunderer version of this carb has an adjustable air door. The air door is the movable plate above the secondary butterflies. Your carb's air door is not adjustable, and this sometimes leads to criticism of "bogging" when the throttle gets suddenly opened all the way. The accelerator pump is quite a bit different than on a Holley, and is not as tunable as a Holley, so it is not possible to compensate for the air door opening by providing more accelerator pump fuel shot, other than within the parameters of the three holes on the pump arm, though three different squirters are made (but these aren't nearly as wide a range as the Holleys). It is possible to make the counterweights on the fuel door heavier by adding lead weight to them, but this is something best left to racers. If the problem is such that the weights must be altered, it's best to sell the carb and buy the Thunderer version.

    One other bit of advice on the Edelbrock - don't overestimate the size you need for your engine. A common myth is that the carb size is "forgiving" because of the secondary air door not allowing unneeded air flow. This is not quite true, and can lead to bogging. Even without the air door issue, too large a carb leads to less lower end response and driveability. Edelbrock has specific recommendations on their website for engine size and power for what carb CFM should be run, and their advice should be heeded without specific instructions from an engine builder.

    Edelbrock.com - Carburetors & Accessories - Calibration Kits

    I'm of the opinion that the Edelbrock carb is capable of delivering better power with better fuel economy than a Holley. The problem with Holley carbs is that they are gas pigs. And they run miserably when you try to lean them out. The Holley Truck Avenger is one of the worst carbs to try to run with economy in mind. While it is a great off road carb, able to take severe angles just as advertised, and it makes great power, it gets two to four mpg less than other carbs.

    I've dug out my old Edelbrock 750, and am going to put it on the 454 in my pickup in place of the Holley Truck Avenger. The Holley makes power, but 6 mpg is a bit hard on the wallet.
  10. inkpot

    inkpot SILVER Star

    Messages:
    8,473
    Location:
    Chandler, Az.
    Howdy! I am pretty happy with the way my 1405 Carter, which is the same as the Edelbrock. Once you get past the basic running/tuning issues, there is one very important mod you should do. These carbs tend to flood on the low side and starve on the high side when you get way off camber. Running on 4 cylinders is a PIA. The fix take 10-15 minutes, and it's pretty much free. Lift off the top plate and you will see that there are two floats and float chambers. There is also a open-topped passage between them running across the rear of the carb. Squeeze a piece of 5/16-3/8" fuel line flat and insert the end into that channel. Push it in as far as possible. Cut it off with a razor blade flush with the carb body. This will block 90%+ of the fuel that shloshes back and forth when you get way off lefty righty. It will not affect the normal driving. I tend to run thru boulders rather quickly, and this little mod keeps the right amount of fuel in each float chamber. No flood, no starve. I can't take credit for this cheap and easy fix, and I can't remember who I heard it from, but it is really good. John
  11. ARC1

    ARC1

    Messages:
    585
    Location:
    Orange County, CA
    wow.. lots of really smart people here.. I feel dumb.

    What happens if the pos(+) line to the electric choke is interrupted? While removing my carb, I followed these lines. Black to ground, and red pos to a bad crimp splice. The copper wire was already mostly pulled out! Fix that.. new inline fuel filters.. dumped 2 cans of Berryman carb cleaner into my carb.. will crank the starter and try to flush out my fuel pump some, and then reconnect everything tomorrow. Wish me luck!?

    i'm not overly optimistic.. seeing all that fine rust dust come out of my fuel pump. Eventho the carb looks clean to me, I bet some of that rust dust is clogging the jets and innards.. probably going to need to take it to a shop for clean/rebuild (about $175). We'll see...

  12. Mark W

    Mark W

    Messages:
    6,171
    Location:
    The Greatland
    You can buy a new 1405 for $200.


    And dollars to donuts, even if powdered rust has gotten through the filters
    it will flush tight through the carb.


    Mark
  13. If the choke wire is interrupted (open) the bimetal element will cool down, reapplying the choke, causing the carb to run rich or even stumble as you try to drive.

    This is why some carbs have a port on the choke that connects to a tube going into the exhaust manifold. The exhaust also heats the bimetal element, keeping it from reapplying while the engine is running, even if the alternator fails and the battery gets low.
  14. And... if the carb doesn't already have them....

    Part number 1465 - Off road needles and seats. Between $13 and $19.

    [​IMG]
  15. cmiller114

    cmiller114

    Messages:
    298
    Location:
    Enola, PA.
    DO NOT pay $175 to clean out an edelbrock carb. Get an air compressor or a can of air and DIY. It's a very simple design and easy to disassemble. Check Edelbrock website under #1406....you can download the manual and some videos there. Check/clean the needle valves and blow out the small passageways including the idle circuits (under the thumscrews) and you're good to go.
    Be sure the hot lead from the choke is to switched power on the ignition circuit, not the battery. The choke was staying closed, that's the cause of the poor running/idle you were talking about.
  16. RMC73FJ40

    RMC73FJ40

    Messages:
    149
    Location:
    Lawrenceville, GA
  17. ARC1

    ARC1

    Messages:
    585
    Location:
    Orange County, CA
    hmm.. I saw an Edelbrock blow-up diagram that scared the c#@p out of me (looks like 200 very tiny parts) .. but if they are only about $200 to replace, maybe I'll do that, and then get the $35 rebuild kit and tinker with this "old" one. Could be educational.. and fun?

    Thanks for all the info and links!
  18. inkpot

    inkpot SILVER Star

    Messages:
    8,473
    Location:
    Chandler, Az.
    Howdy! It may look a bit scary if you haven't been in a carb before, but it is about the easiest and simplest to work on, compared to Holly or Rochester. I think a can of carb cleaner may be your best friend. John
  19. Slapped the Edelbrock 1407 (750 cfm) on my 71 Chev 454 pickup. Fired right up. Did a minor idle adjustment and went for a test drive. The Edelbrock ar-fuel meter shows it's running fat (air/fuel is 1:11). Will get the chart out and select a set of rods or jets or both to lean out the cruise. But the low end response is incredible. Just touch the gas pedal and the truck leaps to life. Stomp it and it lights up the tires quite well. No bog. No sudden pin-you-back-in-the-seat acceleration (unless it downshifts). Acceleration is just smooth, sudden and fast. It's not easy to road test around here, because you're breaking the speed limit very quickly. Much more drivable than the Holley Truck Avenger. We'll see what happens when I try to lean out the cruise. The Holley ran into a brick wall where it was impossible to lean it without backfiring through the carb.

    [​IMG]
  20. middlecalf

    middlecalf

    Messages:
    366
    Location:
    Sweet, Idaho
    I have this on my Edlebrock carb but there is no hose connection and it's not obvious where it should connect into the exhaust manifold. Do you have any info on how to do this? Thanks.

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