A classic engine lives or dies by its carburation. Get it right and the car starts on the button, idles evenly, pulls cleanly from low revs and returns honest fuel economy. Get it wrong — as so many classics are — and you have flat spots, hard starting, fouled plugs and a car that never quite feels well. Carburettors are misunderstood far more often than they are faulty, and setting them up properly is one of the most satisfying jobs in the workshop.
We work on the carburettors these cars actually wear: SU and Stromberg on the British cars, Weber, Solex and Zenith on the Europeans. Each has its own character and its own correct method of setting up, and we have the tools, the jets and the experience to do it by the book — and then to fine-tune by ear and by gauge until the engine is at its best.
Rebuilt before tuned
No amount of tuning will fix a worn carburettor. Throttle spindles wear oval and let in air; jets and needles wear and richen the mixture; diaphragms perish and floats leak. We strip each carburettor, assess wear, renew spindles and bushes where needed, fit correct jets, needles and gaskets, and set float levels precisely. Only once the carburettor is mechanically right do we begin to tune it.
What we undertake
- Carburettor rebuilds — SU, Stromberg, Weber, Solex and Zenith
- Throttle spindle and bush renewal to cure air leaks and poor idle
- Correct jetting and needle selection for the engine specification
- Balancing of multiple carburettors for even running
- Fuel system service — pumps, lines, filters and tank cleaning
- Ignition timing and setup, because fuelling and spark work together
Fuelling and ignition together
Carburation can only be set correctly against a healthy ignition system, because the two are inseparable. We check and set the ignition — points or electronic, timing and advance — as part of any fuelling work, so that the mixture is being judged against a proper spark. A great many "carburettor problems" turn out to live in the distributor, and sorting both together is the only way to a genuinely sweet-running engine.
Living with modern fuel
Today's ethanol-blended fuels are unkind to classic fuel systems, attacking old rubber, corroding certain alloys and evaporating readily to cause hot-starting trouble. Where an owner wishes, we fit modern-fuel-tolerant materials and make sympathetic adjustments to keep a car happy on what comes out of the pump today — all reversible, and all in the service of a car you can simply get in and drive.