Just found my long lost copy of Kevin Cameron's book Top Dead Centre. This is a collection of 'the best of Kevin Cameron articles from Cycle World covering interviews with top-notch racers, profiles of builders and engineers, analyses of riding techniques etc. Wonderful read, even if I did not understand the text at times which most Bantam racers, no doubt, will already know!
P 48 has the following piece which gives an idea of his writing style. Here he comments on the introduction of a 'restrictor rule' for the 1978 Daytona races which necessitated a 'washer' be fitted into the inlet in an effort to reduce top speed. This caused endless problems in fine tuning engines especially for the privateer:
'Here is what I think. Since some setups needed big sets while others tolerated small ones, couldn't this indicate that two states of flow were possible in the inlet system? One flow would transmit a strong metering signal to the carburettors, while the other attenuated that signal, requiring big jets. Could not a given intake system produce both types of flow, but at different engine speeds? If the strong-signal type of flow persisted well up into the rev range, then abruptly switched to the weak signal, carburetion would lean out and seizure could result.'
And on p 196:
'Usually, the reason for using a particular carburettors is not because it flows more air in (that's what bigger carburettors are for) but because it delivers a mixture curve suitable for the application.'
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Sat Sep 30, 2017 8:51 am
