The cowl is the same width as the fuselage, a little more than 5" wide.

The photo shows a DA-50 with Pitts muffler installed and there's a hole cut in the cowl for the muffler's chamber .

Thats how narrow the cowl is.

The DA50 may weigh 8 to 10 ounces less that your Brillelli engine.

My Evolution 45GX2 weighs about 60 ounces with muffler, ignition, spark plug, standoffs and prop attachment hardware.

With a 22-8 APC, my digital fish scale registers almost 26 pounds of pull.

Did you know that some engine sellers list the weight of their engines without a spark plug or a prop nut?

It all has to fly and it all adds to the overall weight of the engine .