If the fiberglass packing in the SuperTrapp mufflers starts to melt or disintegrate, it can clog the plates, causing significant loss of engine power and increases in engine temperature. EXHAUST SYSTEM INSTALLATION
PREPARING/MAINTAINING THE MUFFLERS:
If the fiberglass packing in the SuperTrapp mufflers starts to melt or disintegrate, it can clog the plates, causing significant loss of engine power and increases in engine temperature.
To help prevent this problem, it is recommended that builders replace the fiberglass packing with stainless steel wire mesh packing. It is available from McMaster-Carr (www.mcmaster.com) as #7364T46 for $66.93 per five lb reel plus shipping. This has been purchased in group buys through the Eggenfellner mail list. Check with the Eggenfellner list to determine current sources of this material. You may wish to pre-empt the possibility of problems related to deterioration of fiberglass packing by replacing the fiberglass packing with stainless steel packing before you install the mufflers. It will take about 11 ounces of coarse SS wool to repack each muffler.
CLICK HERE FOR DETAILED MUFFLER REPACKING INSTRUCTIONS
INSTALLING THE MUFFLERS:
The mufflers come with this set of instructions. The hole shown can be anywhere, but probably most convenient for drilling the header pipes if it's on the BOTTOM. The muffler seam needs to go facing DOWN, so heat and noise are not directed at the bottom skin.
Here is a drawing from tech support at SuperTrapp, showing the proper orientation of the disks and end cap. The plates concave side goes aft and the cap concave side goes fwd. Or, to put it another, simpler way, the cap, and each plate inside, all are installed so that you can read the words, stamped in each piece, from the rear.
The muffler bracket may or may not fit between the top of the mufflers and the fuselage skin, as shown on the muffler instruction sheet. If it does not fit, the headers can be cut and rewelded to provide more clearance, or the bracket can be positioned on the SIDE of the muffler, as shown below.
Here's how Jake DeHaan did it on his RV9A with a used 4 cyl Eggenfellner Subaru.
Here's how Larry Simpson did it for his H6-powered 7A.
This is how Larry did his Lord mount ABOVE the skin surface, rather than drill a big hole in the bottom skin for the rubber.
Here's how Tom Moore did it. People, especially those with the widely separated headers, are trying to mount them so the Lord Mounts are in the center area, not further out in the area where pilot & passenger feet will go. You can see how Tom accomplished that here. See Tom's H6 installation website for more Eggenfellner H6 engine installation details. Tom has also produced a DVD on details of installing an Eggenfellner H6.
Here's a front view of John Moody's RV-8 muffler installation, from the front.
This is John Moody's RV-8 muffler installation, from the side. Lots of ways to skin this cat.
It's a real good idea to safety the muffler cap fasteners.
NOTE - The Lord mounts are primarily for vibration control not for carrying weight, although they should be good for about 45 lbs. When installing your mounts, make sure you do not use the mounts to pull the muffler upwards. Use spacers or tweak your brackets so that there is no weight on the mounts. The headers are fairly rigid and will support the weight of the muffler/s. The mounts should not alter the position of the muffler when they are attached, there there should be no weight or tension on the mounts. The mounts are there to absorb vibration and they will pick up some amount of load due to deflection caused by g-forces. If you use these devices to pull the muffler upwards, you'll end up transmitting excessive noise and vibration into your floor panel and eventually you'll tear the mount apart.
NOTE - Be sure to use the extra large washer supplied with the Lord mounts. Install it on the top of the Lord mount. This will act as a mechanical catch in case the steel center sleeve should separate from the rubber donut.
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