Modelling-ABC by Wilfried Eck
Combustion engines with cylinders arranged to form a star. Some had more than one row.
In model kits cylinders lack detail. One has to live with it for it's simply impossible to reproduce the fine cooling ribs accurately. As most WW I rotary engines were of cylindrical shape a more convincing representation can be achieved by sanding the cooling ribs off and winding very fine copper wire around (secured with CA glue). Another point are electrical (ignition-) cords leading from the crankcase to the individual cylinders. Here also fine wire painted the actual colour (mostly black or red brown) gives better results.
Cylinders in shiny chrome silver may be appropriate for a Harley or Kawasaki motorbike, but not for WW II engines. Actually they were of a light middle gray colour (with a slight brown tint). WW I engines were of very dark colour, nearly black, but with shiny ribs. Crank cases (gear boxes) also appeared in variations of gray, only some pre WW II engines showing dull silver. So do not paint all engines alike.
Try to have a look at the real thing by consulting photos, see instalment "Motoren"
Resin parts are a welcome addition for many to
further detail the model. The market for them is now very large, so that hardly
any wishes remain open.
The disadvantage is that you can not glue resin parts with normal plastic glue, but need superglue (CA). The fact that small bubbles or holes can be seen as a result of the manufacturing process must be taken into account.
I myself only use it where I cannot make these parts myself. Because cheap they are not.