The Imp engine became an overhead-camshaft, all-alloy unit of 875cc, which had to be shoehorned at a 45º angle to fit into the pre-existing Imp body. The radiator was slotted beside the engine, at the rear of the car. Kuzmicki's Imp engine was beloved by speed tuners of cars and racing sidecars, as it was very well engineered and strong, and light at 170lbs including carbs, alternator, etc. It was considered the smoothest production four-cylinder engine of it's day and for many years after production ceased.
Below is a photo of the man himself beside the Imp unit: