This is where the Flugwerk 190 differs the most from the original, and where Frasca's Flugwerk 190 differs from the others. This aircraft is the only 190 powered by a Pratt and Whitney C-series R-2800. The C can be differentiated from the previous series by the split nose case. Early C-series applications were the F4U-4, P-47M/N and F8F. This engine is about 1 and 3/4 inches larger diameter the the original BMW 801D-2 and about 140 lbs heavier. The first cowl ring on the original was usually 6.5mm steel and held the oil cooler matrix which took pressurized air from inside the cowl (due to the 12 blade fan in the cowl intake turning about 3 times faster than the prop - in flight the fan wasn't so important) and drew it forward then exhausted it through a gap behind the ring. The next ring held the oil tank. The bulges on the sides of the cowl were to feed cool air to the carb intake diverting the air around the cylinders but they don't on this plane, the carb intake being on top of the cowl between the "machine guns". This engine needs oil cooling so Frasca's people came up with a series of small cores lining the inside of the cowl in front of the cylinders, similar to the original in a way. This cowl has no gap behind the first ring and, of course, no cooling fan. :D I can be obsessive at times ...