The cylinders, instead of being bolted to the crankcase, as was normal practice, were held in position by two circular hoops of alloy steel passing over the cylinder flanges.
"The First Airplane Diesel Engine: Packard Model DR-980 of 1928"
Robert B. Meyer
This type of fastening actually strengthened the crankcase in contrast to the usual method.
"The First Airplane Diesel Engine: Packard Model DR-980 of 1928"
Robert B. Meyer
Cylinder Fastening: Early models had their cylinders strapped and bolted to the crankcase.
"The First Airplane Diesel Engine: Packard Model DR-980 of 1928"
Robert B. Meyer