"Car performance and the choice of conversion equipment"

by Philip H. Smith. 147 pp. 8 1/2in. 5 1/4 in. (G. T. Foulis & Co. Ltd., 1-5, Portpool Lane, London, E.C.1. 25s.).

From the number of letters reaching this editorial office there is clearly a strong interest in improving the performance of saloon cars. Except in a few cases family models are designed with the economics of production in mind and the interests of the majority of owners, so the engine characteristics lean towards economy and flexibility rather than power and performance. There are many misguided ideas circulating about raising the compression ratio, fitting a second carburettor or a straight-through exhaust silencer, and it was timely to receive Philip Smith’s revised book which dismisses many amateur theories as bunkum.

The author, a journalist as well as an engineer, presents his advice in readable form and does not let the technical aspects become too weighty. He discusses how the performance may be improved and the difficulties involved, and although proprietary items are mentioned where appropriate it is explained how to get similar results if the right workshop facilities are available. The importance of having sound bearings is stressed along with the warning that engines are designed with a certain compression ratio in mind, which should not be increased without calculation and very moderate experimentation.

More accent on the cost of conversion, and the best returns for budgeted expenditure, would have been interesting, and we also query the validity of claims made for increased performance in the “facts and figures” section as these are made by conversion specialists without independent substantiation, and can be misleading. Even so, this is one of the best handbooks to help enthusiasts through their first stages of conversions. – M. L. C.