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330 GTC Choke cable wire diameter

Discussion in 'Vintage (thru 365 GTC4)' started by fasthound, Aug 20, 2021.

  1. fasthound

    fasthound Formula Junior
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    Nov 23, 2003
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    While I know many don't owners don't use the choke at all, I am wondering if anyone knows the diameter of the wire connecting the chokes on the three carbs. Mine is so thin that it is effectively useless at closing the choke levers....it just bends. It looks to be about half the diameter of the wire shown in the 330 GTC As-Built Configuration manual.

    Could a 330 GTC owner please put a micrometer on their choke wire and let me know it's thickness? I'm guessing it's supposed to be stainless steel and approx 0.035" or 0.04" diameter? Or bigger?

    Or if anyone knows the actual specification, please let me know.

    Thanks,
    Kevin
     
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  3. Jumprun

    Jumprun Karting

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    Does your car have 40DFI or 40DCZ carbs? I don't know if it makes a difference though. Mine is not stainless. It has a little diamond shape loop on the end. Maybe just use whatever fits best in the lever hole and housing?
     
  4. fasthound

    fasthound Formula Junior
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    I believe it has the DFI, but no, I don’t think it matters. Yours sounds like it matches the As-Built configuration. And in that guide, the photo of the wire almost looks like it’s galvanized or something. Agree with your suggestion, but hoping I can get some guidance as to thickness before I go try a bunch of different size wires.
     
  5. Jumprun

    Jumprun Karting

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    I will measure mine in a couple of hours and let you know.
     
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  6. daytonaman

    daytonaman Formula Junior

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    1.5 mm
     
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  8. fasthound

    fasthound Formula Junior
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    Thank you!
     
  9. Oengus

    Oengus F1 Veteran
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    Confirmed 1.5mm
     
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  10. fasthound

    fasthound Formula Junior
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    thanks!
     
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  11. John Vardanian

    John Vardanian F1 Rookie

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    The No. 25 piano wire is 1.5mm in diameter. I have used it for heater controls.

    john
     
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  13. fasthound

    fasthound Formula Junior
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    I decided to go with #26 piano wire which is 0.063” vs #25 which is 0.059”. Several sites I saw referred to it as “choke cable”. I’m pretty sure it will fit just fine for both heater control valve and choke cable applications. Bought the 302 SS version. Will let you know if I have any problems with it.
     
  14. fasthound

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    I found the reason the choke cable was fouled up. The last mechanic, when reattaching the cross-engine breather hose, managed to shove it so far down onto the breather pipe in the valve cover that it was pushing down (significantly) on the choke cable. It had caused about a half inch bend downward in the cable and the cable rubbed on the bottom of the hose and was also fouled in the choke tie rods on two of the carbs. It took less than a minute to adjust that breather hose so that it will completely clear the path of the choke cable when I run the new wire.

    I didn’t stop to take a “before” photo of that hose because I was so angry at the stupidity and carelessness of how it was connected, I just grabbed a screwdriver and immediately fixed it, then thought to take photos.

    The carelessness of so many little things on this car is frustrating. All relatively easy to fix, but just shouldn’t have happened given what the prior owner spent on this car.

    Anyway, here is the choke wire as it sits right now. When the No. 26 wire shows up, this will be a simple fix. And the choke assemblies on the front two carbs could use a little squirt of WD40 and probably new spindle return springs as suggested by the rusty spring on the front carb and lazy closing of the choke throttle valves at the top of the carbs when the choke cable is pulled. Again, easy fixes but why wasn’t this sorted by the last mechanics when they replaced the top of the back carburetor? Oh well, it gives me something to do and I enjoy finding things that are easy to fix.

     

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  15. Edward 96GTS

    Edward 96GTS F1 Rookie
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    dont forget to make the neat little square at the end of the cable.
     
  16. fasthound

    fasthound Formula Junior
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    Yes, that’s my plan….per the 330 GTC As-Built Configuration guide. That is really a great resource.
     
  17. Jumprun

    Jumprun Karting

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  18. fasthound

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    Well, I can report that .0625” wire is too stiff for this application. I pulled out the old wire and it was only .035” which is too thin and flexible since one of the chokes was sticking causing the wire to just bend and flex vs moving the chokes. I used some carb cleaner and then WD40 on all the chokes just to make sure they were working more smoothly. I will definitely need some new spindle return springs. With some significant effort, threaded the .0625” wire through and it’s just too damn stiff. Not sure that .059” (1.5mm) isn’t going to be a bit stiff as well, but I know that’s what several of you have said is on your cars. Perhaps my choke cable is running in a very circuitous route? IDK. Anyway, I’m leaving them wired with the .0625” for now since I don’t need the chokes this time of year.

    My Jag e-type choke wire is a smaller diameter but also has better clamping at each end, and it only operates the back carb with then a solid rod connecting the other carb choke mechanism…a better set up IMHO.

    As you can see from the photo, this is some thick wire. Lesson learned! Will report back once I’ve re-wired it with smaller diameter wire.

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  19. Edward 96GTS

    Edward 96GTS F1 Rookie
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    is the choke necessary?
     
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  20. TTR

    TTR F1 Rookie
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    Might be if the car is being driven year round in colder climate and especially if parked overnight outdoors or in non-heated structure, just like most carburetor era motor vehicles.
     
  21. fasthound

    fasthound Formula Junior
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    My view is very simple. If the system is on the car, I want it to work as designed, whether I use it or not. My view is that Ferrari, in the owners manual, says to start the car with the choke on. I have owned lots of cars with carbs and have always used the choke when starting and then slowly closing it as the engine warms up. If the choke wasn’t necessary, then Weber wouldn’t have designed it into the carbs and Ferrari wouldn’t have said to use it. To use it vs pumping the gas a few times…well, we can debate that forever. Let’s not, OK? Necessary? No, except probably in the conditions TTR stated above. Personally, I like to use the choke. I know the pros and cons. It’s just how I like to roll. Others see it differently. Viva la difference.
     
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  22. gcalex

    gcalex Formula Junior
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    While I would not default to using the choke (not a good thing if one forgets to open it), I agree with Kevin that if you want the car to be "as delivered" the chokes are desirable to have.

    The chokes are missing from my Daytona, and I am on a hunt for the parts to put them back; if anyone is interested in give-up these parts because they are "not necessary" (which admittedly, they are not critical to proper running of a car), I'd happily take them off their hands... :) (dead serious, so PM me if you have a set of Daytona chokes you'd be willing to part with)
     
  23. TTR

    TTR F1 Rookie
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    Good luck. It took me just 10+ years to find a 90+% complete set. Got couple of missing pieces from Mike P. and had to fabricate couple myself.
    Also, making them work appropriately can become a sizable project in itself, which may require re-configuration/-construction and/or modifications of some OEM control brackets/cables/mechanisms/etc.

    P.S. If I recall correctly, on most Daytonas I've worked on, choke control cable dia. has been 1.0 mm
     
  24. Jumprun

    Jumprun Karting

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    I believe that part of the reason many folks don’t recommend or use the chokes on these cars is the marginal design.
    Even when everything is dialed in, correct wire diameter, bowden tube, tension, etc, the chokes do not always fully re-open after repeated use, there is too much yield in even the correct size wire, it sometimes bows when pushed, and there is all sorts of slop in the levers, rod and connections that it make the reopening a bit unreliable, especially on the front carb, it ends up with all the accumulated slop in the system.
     
  25. Edward 96GTS

    Edward 96GTS F1 Rookie
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    i sourced a complete set for a daytona owner 5 yrs ago. not easy but doable.
     
  26. gcalex

    gcalex Formula Junior
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    Yes, my hope is that someone did some velocity-stack conversion, and has the parts in a box...

    Hope springs eternal.
     
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  27. paul33

    paul33 Rookie
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    Hello,
    I come on this thread since I want to settle back the choke on my 330GTC (early model). With the past owner, the wire has been cup 1cm after the nearest carb and there is no more cable (1,5mm),cable sheath nor any brackets on both sides to fix up the sheath.I identified the hole thru the firewall where this cable could pass (cf pic with blue wire), close by the speedometer cable.
    I attach pictures taken on both sides.
    Could anyone fwd pics of how it is fix up on dashboard side and on carb's side, this would be very helpful to get it "as built" even if I will probably not use the choke (see forum).
    From another hand I do not find any ref. on spares from usual spares suppliers regarding any fixing devices Image Unavailable, Please Login Image Unavailable, Please Login for the wire endings, nor sheath.
    Do you know where I could get it? For the wire itself, I understand that a simple piano wire 1,5mm will do. I suppose better in steel than in stainless for a better cable's stiffness, but let me know.
    Thanks in advance for your comments.
    best regards,
    Jean- Image Unavailable, Please Login
     
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  28. fasthound

    fasthound Formula Junior
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    The hole with the blue wire is the hole my choke cable goes through. I will shot a couple of photos of my under- dash layout as best I can.
     

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