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Lamborghini Countach gearbox, Weber carbs rebuild


What to figure out for the 1985 Countach LP500S Downdraft

  • This Countach came to us due to the previous shop that work on the car saying the poor running condition, back firing
    was due to the heads needed a rebuilt, this after recent engine our major service
  • Testing the weber cab balance with airflow meter confirmed imbalance in carbs. No two carb barrels had the same reading
    with 7.8hg to 1.2hg being the range across all 12 barrels...  while mixtures screw settings were also completed messed up to go with the airflow
  • Rebuild and setup 6 weber DCNF carburetors, air flow balance them, refined mixture screw settings
  • Client drove their Countach car felt as if it had 30 per cent more power than before with a smoothness not experienced before
  • This lead to request to get the A/C working, sort out all the electrical items not working, rebuild gearbox due to bearing noise and difficult getting into 4th and 5th gear, update ignition system, while getting the tach working


 

Rebuild Countach 5 speed gearbox
  • The gearbox was making usually bearing noises at idle and when driving
  • Shifting between fourth and fifth gear was difficult, inconsistent in its smoothness 
  • The clutch release bearing was making a noise, clutch felt vague 
  • Upon disassembly we discovered the fifth had been installed backwards
  • Doing this causes the gears to bind when the upper input shaft is correctly torqued 
    the shop that rebuild the gearbox got around this by tonguing the locking nut at the end of the shaft
    just to the point were the gearshifts were about to lock up 
  • They added shims between the rear shaft bearing and the fifth gear in and attempt to reduce the amount the top input gear shaft move reward toward the casing when tonguing the locking nut. 
  • This resulted in the upper input shaft being able move back and forth, causing the gear fork for 4th and 5th to wear enough to causing the binding when shifting between fourth and fifth gears, this also wore out the spigot bearing in the crank for the input shaft, along with unusual wear in the clutch disc. 

 


Design build LED lights for interior, install MSD ignition, check valve clearances, weber carb rebuild and setup, get A/C working, replace fuel level sender, replace fuel pumps
  • S2 Squared here in Edmonton design and 3D printing the LED light units to create the LED lights to fit into the console light fitting for the centre switch and ventilation panel. As built the factory light fittings had no bulbs in them.
  • We installed a MSD 7AL ignition unit setup for a V12 engine
  • Removed A/C lines that were leaking, replaced with new lines built from local hydraulic and A/C line specialist
  • Removed right hand fuel tank to replace fuel level sender unit and clean tank internal surfaces
  • Remove fuel pumps from left hand tank, clean out decades of crusty material, install new pumps
  • Meanwhile... as the engine was out and carbs off for a rebuild we measure valve shim clearances, replacing shims were needed
  • We rebuild the carbs, reset their float levels and mixture screws
  • Once carbs reinstalled, we air flow balanced the two barrels in each carb, then airflow balanced all the carb to airflow level for the correct idle
    the offered up throttle linkage to then tighten down each carb to the linkage while maintaining proper airflow balance
  • Fine tuned mixture screws for correct running