1. 5th avenue Rob

    5th avenue Rob Well-Known Member

    Messages:
    48
    Likes Received:
    23
    Joined:
    Jun 15, 2018
    Location:
    Arizona
    Removing the lean burn and adding a four barrel carb and HEI ignition. The junkyard intake is some kind of high rise unit not sure what it came off of. Date code looks like 77 has a big thermostat housing that required me to move my AC bracket to the right side two inches. Big pain in the neck. Intake ports are not as big as other intakes I have used almost same as my 2v heads. Is this a 318 4bbl intake?

    20180817_200444.jpg
     
  2. 5th avenue Rob

    5th avenue Rob Well-Known Member

    Messages:
    48
    Likes Received:
    23
    Joined:
    Jun 15, 2018
    Location:
    Arizona
    This is after intake installed.

    20180821_211954.jpg
     
  3. BudW

    BudW Moderator Staff Member

    Messages:
    3,161
    Likes Received:
    864
    Joined:
    Mar 4, 2012
    Location:
    Oklahoma City
    The intakes that use the Aluminum C-171 A/C compressor (started late ’78 to early ‘90’s) use the smaller off-center thermostat housing. Some (not all) ’78 intakes use this design – but most ‘78’s also used the cast iron RV2 style A/C compressor.

    The RV2 (cast iron) A/C compressor will work for both styles of intakes. The C-171 (aluminum) compressor will not (not without modification).
    Speaking of which – I would like to see what you did, exactly, to get your C-171 compressor brackets to fit (if possible).


    Intake ports: https://www.forfmjbodiesonly.com/classicmopar/threads/my-ebay-360.7680/#post-84569 drop down to post # 3 (if it is not directed there) for how I determine large vs. small port small block cylinder heads and intakes.

    I would guess (no hard numbers to go by) that 9 out every 10 small block 4-bbl intakes are the large port design (so, about 1 out of 10 are small port). If you already have a 318 (which you do), a small port intake would be your best choice.

    I do not have an extensive list of casting numbers on intakes, as I do other parts – but if you can get me the casting number off it, I should be able to tell you if it is a small or large port intake.
    There will be another number cast on the intake “18436572”, that many think is a part or casting number, but that is your engines firing order.

    Did you get a longer throttle cable?

    What are you going to use for kickdown linkage?
    BudW
     
    5th avenue Rob likes this.
  4. 5th avenue Rob

    5th avenue Rob Well-Known Member

    Messages:
    48
    Likes Received:
    23
    Joined:
    Jun 15, 2018
    Location:
    Arizona
    Well it is installed and running. It runs very strong for a 318 but as stated the kickdown rod is too short and my car shifts too soon. I will cut and weld the rod with some allthread so I can adjust it to the right lenth. I will take some picks of the ac btacket mods as soon as I can it was not too bad just drilled new holes and raised it two inches and to the right. Used same belts. Now I must mod my duel snorkel air cleaner. Wont clear ac. Cant win.
     
  5. BudW

    BudW Moderator Staff Member

    Messages:
    3,161
    Likes Received:
    864
    Joined:
    Mar 4, 2012
    Location:
    Oklahoma City
    I “think” some ’76 F-bodies came out with dual snorkel air cleaners, but not any with outside air (that I know of).
    FMJ bodies are just not made for dual snorkel cleaners – especially ones with A/C.

    An un-silenced air cleaner (or aftermarket version) will fit and is an option. If you plan on driving the car much on highways, the using the outside air will give a decent increase on fuel mileage. If most driving is city driving or occasional driving, the outside option will not matter much.
    68_383us_03.jpg
    In my case, I have a pair of damaged factory single snorkel air cleaners that I plan on using on my big block changeovers. I need to transfer the snorkel over for outside usage and some other minor repair work – but the trap doors still work. These came on ‘72 340’s and some 440 cars.
    AC 72_340_01.jpg
    AC 72_340_02.jpg
    The trap doors open when engine vacuum is low (ie: when engine is making power), then closed all other times. It does not give the same music as an unsilenced air cleaner does (at WOT (Wide Open Throttle)) but can still make some noise – if you are into that kind of thing.
    With the outside air hooked up, I can still get better fuel mileage – and have the airflow of a second snorkel, when needed (via the trap door).


    The top kickdown rod can be modified (welded on) to make fit. It is a bit longer (about an inch, if I recall correctly – but don’t quote me on that) and also wider – so you might need to make it go outwards a bit, as well.

    Thermoquad's are a good 1 inch wider – if not more. I think the AFB/AVS/Edelbrock is about ½” wider – if not more. So, if you need to make modifications – you might as well make it right in both directions.


    Did you get a 4-bbl throttle cable?
    The 2-bbl throttle cable sometimes will barely fit but is just not long enough. The first time you hit the gas, the engine will tilt to passenger side of engine compartment, pulling on the throttle cable at same time (which is already at bare min distance as is. What happens is engine movement will pull the throttle cable back in its holder – which in turns will leave your throttle stuck in an open position. That is not a good thing and can lead to “bad things” very quickly.

    It is not worth the damage to car or to you with using the “too short” 2-bbl throttle cable – if though it just barely fits. After throttle cable is adjusted, there should be a fingers width from cable to anything else – to allow for engine movement.
    BudW
     
    5th avenue Rob likes this.
  6. Oldiron440

    Oldiron440 Well-Known Member

    Messages:
    958
    Likes Received:
    187
    Joined:
    Apr 25, 2017
    Location:
    Iowa
    If need be a /6 cable works well for a 4 barrel or a big block swap.
     
  7. 5th avenue Rob

    5th avenue Rob Well-Known Member

    Messages:
    48
    Likes Received:
    23
    Joined:
    Jun 15, 2018
    Location:
    Arizona
    Cable is fine I moved the cable hold down to the carb pad. I am using an edelbrock 600cfm and an adapter that I port matched to the intake. The air cleaner is off of an early 90s b250 van with a 5.2 magnum. The early magnums used duel snorkel air cleaners with standard 4v carb opening. I will move the openings farther apart so I can get cold air from the right side too.
     
  8. BudW

    BudW Moderator Staff Member

    Messages:
    3,161
    Likes Received:
    864
    Joined:
    Mar 4, 2012
    Location:
    Oklahoma City
    I am only mentioning the 2 bbl vs. 4 bbl throttle cable because it has been a problem with several of my friends (and myself), before. Having a throttle cable be pulled back from engine movement (under power) can be a dangerous thing – especially if you are in an area with a lot of traffic or pedestrians close by at the time.
    I have run into a fence in a beat-up pickup, after a 4-bbl changeover. The cost to fix the fence cost more than damage to the pickup.

    I’ll take your word you are fine – but please make sure the throttle cable has plenty of room in two areas:
    - The cable attachment/adjustment area. The clamp should be on the cable metal end about mid-way (depending on adjustment needs). If the cable clamp is close to either end – it causes problems.
    - Also, make sure the cable (black part) has wiggle room after adjustment. If the cable is taunt (between the clamp and firewall) when at rest, then when the engine tilts under acceleration (or power stall), the cable will pull itself rearwards in the clamp (which will hold the throttle open).

    This picture is from a forum member here who installed a 4-bbl.
    IMG_20161201_175454mA.jpg
    Two things that I see in this picture: One is the cable adjustment clamp (yellow arrow) is holding the black cable down – and not at the metal end (red circle). You can also see the metal part of cable, is not touched at all (orange line).
    Second item is the cable has 0 (zero) wiggle room (pink line) between engine and firewall. In this case, when engine tilts to passenger side of engine compartment (under acceleration or power stall), the cable WILL pull on the cable clamp, pulling the cable rearwards (in other words, in a throttle held open position).
    Another issue was a lack of kickdown linkage.

    This member needs a longer cable (which I think he fixed).

    Lastly, the cable in clamp should be parallel with valve cover – and not in an angle. The same thing for kickdown linkage. The Thermoquad engine throttle cable and kickdown linkage is, for the most part, on top of the valve cover (which I know Thermoquad is a bit wider than the AFB/AVS/Edelbrock carburetor design is.

    Here is a picture I took from my '77 2-bbl:
    20180908_101932r.jpg
    You can't see it, but the throttle cable (between engine and firewall, can be moved about 1½" either way - so it has plenty of movement area.
    20180908_101932mB.jpg
    Red lines are the metal cable adjustment area. Pink lines are the clamp width. Clamping the cable on the black plastic area is a very bad idea. Also, clamp is designed to hold not damage the metal end - but a person (or engine) can and will be able to pull the cable right out of adjustment - if a person tried.
    Having cruise control makes pictures of this, a bit more difficult.


    All I want is for you and others to be safe, out there. If everything is good, then great. I have worked on enough of these cars to see un-safe problems out there – and I just don’t want you to become another statistic.
    BudW
     
    5th avenue Rob likes this.
  9. 5th avenue Rob

    5th avenue Rob Well-Known Member

    Messages:
    48
    Likes Received:
    23
    Joined:
    Jun 15, 2018
    Location:
    Arizona
    You make a good point. I will look at again I cant aford any misshaps. Had my throttle stuck on my 69 Polara when I was 18 the four wheel drums would not hold the 383 so I popped it neutral I can still remember that sound. Wide open for 30 seconds before I fumbled the key off
    And then Pow! Lucky it was only a blown out muffler.