30-04-2020, 03:31 PM
I have come to understand that the Mk III as raced by Lotus had a real, 8-port block with round inlet ports, and that Clive Chapman still has the block, which was planned to figure in the Mk V.
However, the Mk III as sold at the end of the 1951 season had indeed a couple of tongues projecting into enlarged inlet ports, as described above. That Australian Derek Jolly also de-siamesed a block seems beyond question, and that block made its way to Hornsey. Now, whether Chapman or Jolly did it first is debatable, we may never know.
There were several de-siamesed cars built after the 750mc relaxed the ban. My father owned one of them for a while, Complexity, whose engine lay almost on its side and had the manifold face of the block machined at an angle, removing metal from the lower edge so as to provide straighter inlet and exhaust ports.
However, the Mk III as sold at the end of the 1951 season had indeed a couple of tongues projecting into enlarged inlet ports, as described above. That Australian Derek Jolly also de-siamesed a block seems beyond question, and that block made its way to Hornsey. Now, whether Chapman or Jolly did it first is debatable, we may never know.
There were several de-siamesed cars built after the 750mc relaxed the ban. My father owned one of them for a while, Complexity, whose engine lay almost on its side and had the manifold face of the block machined at an angle, removing metal from the lower edge so as to provide straighter inlet and exhaust ports.