From the MEWS archive, this purposeful looking C.I. engine was exhibited at a Bristol exhibition. It was designed and built for use in radio controlled model aircraft. It is a four stroke of 6.5cc.

the compression ratio is variable from 7:1 to 25:1 by pivoting the cylinder and head assembly around the camshaft. It is capable of 7500 rpm with a 12 x 6 prop and 5400 rpm on a 14 x 6.