Posted Monday, October 29, 2012 @ 11:48 PM
The mufflers are the most "experimental" item on this rebuild and they've been going through some changes as the engine has been running and testing. The original muffler had a 12" long canister, and although it was quiet, It was really long and needed a support that would dampen vibration and mount onto the fuselage. I never really figured out a mount system, and I didn't really want to drill big holes in the fuselage. So, I'm trying a new design that is shorter and lighter, and doesn't need a mount.
The new design uses a 4.5" carbonfiber canister and an end cap called a SuperTrapp (used in high-performance motorcycle mufflers) with disks that send the exhaust out radially. They weigh about half what the others did (a pound each), and are almost as quiet. Definitely a different look for a Fournier. We'll see how they work when flight testing starts in the Spring. The adventure continues...
[Edit by dannparks on Tuesday, October 30, 2012 @ 01:45 AM]
[Edit by dannparks on Tuesday, October 30, 2012 @ 01:46 AM]
Dann Parks • RF4D #4051 N2188 • now flying!
Pictures at: https://picasaweb.google.com/111628310900713778468/RF4D_N2188?noredirect=1