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Carburettor repairs / overhaul
SU, Solex, Weber, Dellorto, Pierberg, Nikki, Autolite... etc etc etc.....
Modern fuels - There is very little doubt that modern fuels can be quite aggressive towards many of the materials used on classic cars. I'm not about to write a book on the topic, but let's just say it is already fairly well known and documented.
In addition to material compatibility, there are then difference in regards to both 'octane' and 'calorific' values when comparing traditional and modern fuels also. Octane and Calories are two different properties of the fuel, hence don't confuse the two.
Thorough and correct overhaul (As per the below)
Below is a Weber DCOE 40 which has been stripped, cleaned using multiple methods and stages, inspected, checked and is now ready for a full overhaul and rebuild. The sad part about this case is that it is one of the many sent to us which had supposedly been recently done by others. However, as ever we found 'beads' present internally, bearings which were filthy, sloppy and had clearly not been touched in years and many other factors which simply aren't good enough.
Hopefully you'll have your carbs overhauled by AG Classic Car Tuning, however even if you don't......then please ask 'whoever' for pictures of your carbs in a fully stripped down stage as per the below. Superficially cleaned on the outside simply isn't good enough......however it is exactly what a lot of other companies seem to be doing!! Take note.....it is becoming increasingly common.
The above twin HD8 SU carbs were taken from a Healey 3000..... During a tuning session it revealed that the jets were worn, the idle air bypasses had no 'cause or effect' on idle speed and other issues. On strip down for overhaul, it became clear that these carbs had been overhauled before, during which they'd got somethings right and some things very wrong. But ultimately the reason for the idle air bypass screws having no effect...became very clear! All resolved now, refitted an re-tuned for the owner to enjoy once again.
When carburettors are blocked or need repairing?
The carburettors used on most classic cars consist of float bowls / reservoirs, jets, needles, emulsion tubes and various fine capillaries. It is incredibly easy for these to become blocked, and result in a carburettor/s which will not function correctly.
Sometimes they can be given a simple clean, however more often than not they can require a full overhaul and either a service kit fitted, or a more complete repair/overhaul kit fitted.
On the below pic, the green slime is what existed inside the float bowl of one carb from a set of twins........not difficult to see why only one carb was functioning!!!
Below are a 2 sets of Triple Zenith 40 TIN down draught carburettors.
- Fully overhauled
- Deep cleaned
- Pressure tested to observe maximum needle valve capability
- Float height set physically and via external sight measure
- Engineer blue'd on all gasket surfaces
- Prepped to Porsche's exact specification.
Mechanical Damage to Carburettors
Most carburettors have 'wear and tear' maintenance items which allow them to function.....shafts, bearings, needles, jets, floats, valves. In the worst case scenario, the result is petrol leakage and the risk of fire.
Of lesser severity is when the vacuum created by the engine can draw air in via a leaking spindle bush, diaphragm, seal or gasketed seem. Instead of pulling in a fuel and air mix as per the carburettors design, its far easier for the engine to pull in air instead.
Carburettor Repairs and Overhaul
On a 'case by case' basis, we are often able to carry out repairs and overhaul to almost all carburettor makes and models. As a general rule, we do this as an extension of our tuning work, to then be installed / setup & tuned by AG Classic Car Tuning.
Ofcourse....subject to the relevant overhaul kits being available!!
Above....MK1 Ford Mustang 289Ci....Ford Autolite 4100 carb removed, overhauled, refit and tuned by AG Classic Car Tuning.