Scout 800 232 carb vacuum head banging

Discussion in 'General IH Tech' started by 70scout800b, Oct 20, 2009.

  1. 70scout800b

    70scout800b Farmall Cub

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    Hello everyone, I have searched the entire Internet for some answers . Maybe y'all can help. I just bought a 70 scout 800 b w amg 232 I6. Man trans, and a unique holley one bbl 1920 carb R4542 3509. The carb has two small vac ports I have no idea what the correct connections are. 1 large port below and angled, for the pcv I guess. Plus I don't know where the daspot vacuum comes from. The dist advance is unconnected, but don't know what to connect where. Pretty much I need a walk through on all vacumm line connections. Plus there is an unknown vacuum part located on drivers side firewall behind the engine int/exhaust manifolds. it it round and flat one line proceeding downward, two ports off the side and a threaded center neck on top. It says Holley on it's top face. What is it? Please help if y'all can. The carb has man choke btw .Thank you.
     
  2. blybrook

    blybrook Farmall Cub

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    I'll take some pictures of my '69 800 that has a 232. That should help you a little. I don't know if I have the holley carb or not, but I think it should get you in the ball park.

    The Holley 1920 is a common carb for these engines, you may also find Motorcraft or Carter models. Rebuild kits for all can be found at your local Napa if you can get them to utilize the books instead of the computer.

    I'll post pictures up tomorrow of how my lines are run. As for the firewall connection, I'm not sure what it is, and I have it on both my '69 & '74 with the I6; and both are disconnected. No problems what so ever running it that way.
     
  3. Eric VanBuren

    Eric VanBuren Lives in an IH Dealership

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    Most of the dash pots on IH early vehicles are purely mechanical no vacuum connection.

    The thing on the firewall is part of the road speed spark advance system. It blocks off the vacuum source and bleeds what ever vacuum that was present in the line between it and the advance can when road speeds are above a certain speed as indicated by the "spinner". The spinner is in the speedo cable and it makes or breaks a ground for the solenoid.

    Sorry I can't help you with the rest of the vacuum other than originally the vacuum advance went to the firewall mounted solenoid. For optimum performance and fuel economy you want it to go to a port on the carb that only has vacuum when the throttle is opened, not at idle.
     
  4. 70scout800b

    70scout800b Farmall Cub

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    Thank you guys so much. I'll look for that pic asap. Does anyone know where the two small vacuum ports ( yes 2) that come off the holley 1920 lower body go to? They are both in the same place just one barely above the other. I figure one is the the vac advance, no idea about the other ( the top one) connects to. It has a small amnt of vac at idle, that increases with throttle. The lower one was connected directly to intake manifold vacuum but who who knows if that connection was " southern engineered" . Can't find any info online or from holley about this weird version of the holley 1920. Or the correct connections for these two vacuum ports.
     
  5. blybrook

    blybrook Farmall Cub

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    OK,

    My '69 does have the Holley carb on it, with only one vacuum line connected. The bottom line on the back of the carb is blocked off with a bolt, the top is connected to the vac advance on the distributor. The only other vac line that I can locate is the one coming from the fuel pump to the intake.

    I have before pictures with no coloring, then edited pictures *in next post* with the lines marked, red is for the distributor (rubber to hard line to rubber); blue is for the hard line coming off the fuel pump.

    No vac lines ran to the firewall and since both rigs don't have a working speedo, I'm not worried about hooking that contraption up.

    I also checked my manual (Chilton's) for the 800 *I have yet to order the one from binder books for this rig*, and it does not have a vac diagram in it. The one for my SII does IIRC.

    HTH

    Bill
     

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  6. blybrook

    blybrook Farmall Cub

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    Here are the photos with the lines marked. See above post for color meaning.

    Sorry bout the quality, was marking it up in MSPaint with a laptop touch pad...

    Bill
     

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  7. 70scout800b

    70scout800b Farmall Cub

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    Thank you so very much. I will be posting pics this weekend for further "grasshopper" help! Got a few more questions for you pros:
    1. What is the carb rebuild kit for my holley 1920 list 4542, and where can I get it this weekend?

    2. What are the vacuum specs for the engine, carb, vac advance, etc?

    3. What is the correct fuel flow pressure to the carb, I got a aftrmrkt regulator?

    4. What is that open metal port/ nipple on the top of the center of the exhaust manifold, where did it connect?

    5. How many turns out should the correct ballpark idle mix screw be?

    Thank you again for your fast responses, God Bless
     
  8. blybrook

    blybrook Farmall Cub

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    1. Go to NAPA with those numbers and have them look it up. They can get you the parts.

    2. This is a 3 page section of my chilton book (normal is 17-22" Hg). I'd recommend getting the binderbooks repair manual for the exact numbers.

    3. approx 4 psi. 3-5 psi is ideal, but most information I've read has it at 4.

    4. I believe it was left there after molding the manifold. I've never seen one connected (someone else may chime in and correct this statement)

    5. That depends on the carb and the tuning of the engine. Get a holley carb rebuild book from NAPA and it will have the initial dial in numbers for you. I don't have my book handy to look it up.

    HTH

    Bill
     

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