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zdude1967

Removing the manifold need advice

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    I am putting on headers and will need to remove the exhaust and carburetor manifold for the new gasket. I want to make the process as simple and successful as possible and want to be able to just bolt the carb manifold back on, start the car and go. Is there any special process for handling the carb manifold, such as storing with the carbs facing upright or any other thing I should know to make carb and manifold removal and re-install successful. Will I need to re-adjust the carbs after the go back on?

    G

    Edited by zdude1967
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    Glenn,

    No, it's not that hard. In fact, I've done it twice in the last week. :).

    You'll need the following tools:

    1. Torque wrench - needs to go down to as low as 5 pounds (or 10)

    2. Rachet wrench plus long extension and short extensions 10mm, 12mm, 13mm, and 14mm sockets.

    3. Universal joint for rachet - not required but nice to have

    4. 10mm and 12mm closed/open ended wrench

    Start by removing the air cleaner and cover (bolts on outside are 13mm, studs that hold the outside cover to the aircleaner to the base are 14mm, (you could use an adjustable wrench for these, but if you want to torque them later you'll need the sockets) then the heat shield. Remove all the hoses, gas, power brakes, air cleaner to float bowls, etc. Undo the throttle linkage by removing the cotter pin.

    I think (I'm doing this from memory) there are 16 or 17 bolts/nuts you'll need to take out. My intake manifold at the top was held in by bolts and then by nuts/washers at the bottom where it is held on with the exhaust manifold too, but I've been told that they came with washers/nuts (don't know if that is correct). If you start at the bottom, it's a bit easier because then the top of the intake manifold is still being held on You can actually get to all of the exhaust manifold nuts by going under or through the carbs/linkage assembly (that's why you have the extensions!)These are 12mm. Leave the exhaust manifold hanging on the studs. It won't fall off.

    Loosen all the intake manifold bolts or nuts just to make sure you can get them out. Remove the two bolts in the front of the head that hold the fuel rail in place. Taking the fuel rail off will just make the job easier.

    Two of the bolts in the intake manifold were a little tricky to get out because they come so close to the manifold when fully backed out, you can't get the socket in between. You can either use the open end wrench for these or take out the other bolts you can get out easily and then loosen these two last, while supporting the manifold with a hand. As the intake/carbs pitch forward from the top (resting on studs on bottom) you will have room to loosen these two bolts.

    After that, it's all downhill. Intake manifold/carbs should lift right out (not heavy). I'd store them close to flat if possible. Just put something under the water tube that runs between them for support. I wouldn't recommend supporting them by the linkage. You can set them at 90 degrees on the intake manifold flanges, but make sure you are setting them on something that will not score or damage the flange. Setting them straight up like this will dump out the gas from the bowls and also probably spill your damper oil, so I wouldn't recommend it. I'd go with as close to flat as possible.

    Exhaust manifold - You can try to loosen the three bolts that hold the pipe to the manifold, but they'll probably snap off (still ok since you're not going to use it) or just cut the pipe and lift the manifold and pipe assembly out together.

    Tuning - after the first time I did this, the carbs were dead on. No balancing necessary. After the second, I had to make a very minor adjustment to the balance. If your mixture screws were set correctly before and you didn't hit them taking the carbs off of or set the carbs resting on them, then you should be ok.

    Hints - Make sure you use a header gasket, not an OEM type intake/manifold gasket. Make sure you get all the old gasket off the head and intake manifold. Ask the seller if they recommend using Copper Hi - Temp RTV on the exhaust flanges of the header. Just an extra measure off caution to make sure you don't get a leak. I had to take mine back off because I had a small exhaust leak. I had the exhaust manifold shaved and the shop recommended the RTV even though it was now perfectly smooth. I figured two times in a week was enough and a tube of RTV was cheap insurance!

    Assembly is pretty much the opposite of the take down. Bolt/Nuts are torqued between 8-11.6 pounds each. I torqued the bolts that hold the fuel rail to the front of the head to 5.5 pounds. Air cleaner assembly bolts to carbs at 5lbs.

    Good luck. Any questions, write back or PM me.

    Bob

    Edited by bobc

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    One minor step that Bob left out: use plenty of penetrating oil like PB plaster or Kroil on the nuts. Your careful planning regarding properly handling the carbs to ensure a quick and easy swap might go out the window with the frustration of rounded nuts or broken studs. The next thing you'll know you'll be tossing the carbs aside and going at it with a sledgehammer.

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    Thanks for the information. I am installing 3 into 2 headers with a 2.5 inch pipe and flowmaster muffler. I have the headers already but am open on the muffler. Any suggestions???

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    Glenn,

    Good advice from Mike. I used Kroil (bought it online) on several bolts, but they were beyond hope. Soak em overnight or longer, and go slow with the wrench. Snapping a stud is absolutely no fun. If you do, STOP! My advice is let a pro handle it if possible. You can try an easy out, but be careful not to snap it off in the stud. Then, you're in a world of hurt. I know, I've been there!

    Bob

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    3 into 2 is the way to go and I think Flowmaster is as good as any. On my car, I actually have a short glass pack in the straight part of the pipe and then a Flwmaster on the end. I also run 2.5 inch pipe and those who notice say it sounds very good. From inside I like it pretty well, but would like a little more of the glass pack sound. I did have two glass packs but it was too loud. I replaced one with the Flowmaster. Reduced the noise level, but introduced a little "flowmaster" sound that I really don't prefer.

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    Quick follow up question. I planned on storing the carbs in basically the same position as they are in when installed. Bob is this the position you are suggesting? Also I have a bad history with ez outs if I break one anybody have a suggestion where it should go in phoenix for professional removal

    zdude1967

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    Glenn, yes. Keep them as horizontal as possible (like they are mounted on the car). Don't worry if you tilt them some, you'll be fine.

    I stored mine in a vertical position the first time I took them off, but as noted, the fuel and oil will leak out. No big deal, but it's better to keep them horizontal.

    Bob

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    On the carbs as was stated, the only thing that will happen if you tip the carbs is the oil and a little gas will spill. I have three suggestions .

    First take a file and pass it over the header flanges . Pass it so more than one flange is contacted at the same time. This will true the header.

    Second thing I recommend the use of the gasket sold by Motorsport for there headers. It is a heavy duty gasket . I know personally that it is a good part , plus I have friends that race Z s and they recommended it to me. Even removing the headers later you will likely still have a good gasket.

    Third Have a look at Dynomax turbo mufflers . I have the same set up as yours and I have had several people comment on the sound of my Z. Especially when my Z was on the dyno at my Club's Car Show. I cannot remember which part # it is , but the entrance is in the center and the exit is on one end of the oval shaped muffler. This will allow you to tuck it up in the fender well so it is hidden and the tip is centered in the slot provided . I bought mine from Summit and they shipped it for free and I received it in two days. This is not a quiet exhaust and if it is too laud , use a thrush glass pack. They have a perforated inside section , rather than a louvered section that closes off some of the flow of exhaust. My 2cts Gary

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    Quick follow up question. I planned on storing the carbs in basically the same position as they are in when installed. Bob is this the position you are suggesting? Also I have a bad history with ez outs if I break one anybody have a suggestion where it should go in phoenix for professional removal

    zdude1967

    I would suggest not using an EZ out. If the stud didn't come out of the head along with the rusted nut and instead broke, then it is usually too stuck to come out with an EZ out. Penetrating oil (as already suggested), tapping on the nut with a punch and hammer to help loosen (the vibration cause by repeated tapping helps the oil penetrate and break up rust) , and heating the nut. If you break a stud flush with the head bite the bullet and drill it out and put in a thread insert. It sounds like you already know what happens when the EZ out breaks. If the stud breaks above flush (enough to grab with vice grips)more oil, tapping (lots) and FLAT jawed vice grips. One more thing.....PATIENCE, and lots of it.

    Steve

    Edited by doradox
    clarification

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