Paul Knapp assembled castings for his model Pratt & Whitney R-985 Wasp Jr. engine (also on display), and then cut them in half as a visual aid. The model is built as a cutaway so you can see some of the craftsmanship that goes into the design of an engine like this. Much of the fine machine work of the basic engine casting is covered up once the nine cylinders and other parts are bolted on. This assembly represents many hours of work in pattern making, casting and finished machining.
Mr. Knapp believes that true-to-scale engineering should be recognized as a copy of the full-size counterpart. However, many full-size engines cannot be scaled exactly because of physical limitations. For example, a carburetor can be scaled down, but the air and gas molecules passing through it cannot.
Mr. Knapp concentrates on outside features to ensure that appearance is as close to the real engine as possible. Then, if necessary, he modifies internal components to make the engine work when finished.