11-08-2021, 08:50 PM
Mike, if you recall a couple of years ago I did an analysis of the variations between a collection of Low Compression heads dating from 1923, there is quite a difference in the combustion chamber area as well as the cross section of the transfer port depending on what year and casting type. Obviously Austin were messing with things over the years, quite why seems strange because some versions would theoretically perform better than others, even if only subtle variations. I think the quoted outputs are likely simply a marketing tool but it would be interesting if one could be bothered to carry out dyno tests on otherwise identical engines today. Probably all somewhat academic and of little real time use to most seven owners today but still something one or two of us may find interesting.
Black Art Enthusiast