I am bashing up a 1/5 +/- semi-scale Curtiss F6C-4 and ordered a fiberglass ring cowl (Fiberglass Specialties). I've never attached a ring cowl before. This has no obvious attachment to the fuselage from the images I have, and I'm not familiar with how original ring cowls were attached. At this point I figure on adding four dummy pistons (the "real" plane had a 9-cylinder radial) with attachment points on the tips and bolt them into attachment blocks glassed into the cowl lining.

Anyone have tried and true or better ideas? I assume there was some kind of framework on the full scale to position the ring.

I would bend up a few brackets that could mount the inside of the cowl to the firewall

This is the way the real Jungmeister did it. I cannot document the ring at the fusealge, it may have been fastened to the engine, so that everything would vibrate together.

In my research into a Kinner engine, one of the technical drawings showed that a rocker arm cover bolt was a long stud or standoff, on a number of the cylinders; presumably to bolt the cowl to.

If this is going to be a internal combustion engine airplane, you would probably be better off with a system like MinFlyer suggested. The vibration will likely tear your dummy engine up.

Les