In December’s issue Mark Hughes talks about the engine used by Nelson Piquet in qualifying and, as it turned out, the race at the 1980 Canadian Grand Prix. Over the years I have read speculation about this engine and am writing to clarify the issue.
In 1980 I was an engine builder with a first-rate company specialising in rebuilding DFVs, and was entrusted with building this particular engine. The engine was DFV 318 and was standard in every way apart from the pistons. Usually we used Cosworth pistons but on this occasion we fitted semi-slip ones made by another manufacturer, which improved the performance on the dyno by around 5bhp. However, as the article correctly states, they were known to be fragile and incapable of lasting a race distance but as it was a qualifying engine they were not required to.
The engine did not have a higher compression ratio as has been speculated. I built the engine to the specification laid down by my supervisor so all credit must go to him or whoever advised him for using different pistons, as they did indeed improve performance which, in turn, helped Nelson Piquet secure pole position for the race.