Jim,
I welded Rich Henning’s exhaust tips on. They work
great!
From Rich Henning’s webpage http://www.lancairlegacy.com/RHGroup.html
“Exhaust tips $99.00
The exhaust tips are mandatory if you purchase the
standard exhaust system from Lancair. On my first flight the exhaust gasses
burned my paint. I made a trip to Bend, Oregon for some
other repairs and went over to the place that actually made the Legacy exhaust
system and told them of the problem. They told me that they were basically
unable to fix the exhaust. My reply was being the 5th plane of over 200 kits
sold, now would be the time to fix the problem. I was on my own. I came up with
a easy fix and the perform flawlessly. These tips are simply welded onto the
exhaust. If you have any other question please e-mail at rhgroup@earthlink.net or call
1-949-278-7482”
Jim Vosters
Legacy # 186 - N357V
-----Original Message-----
From: Lancair Mailing List
[mailto:lml@lancaironline.net] On Behalf Of Jim
Cameron
Sent: Friday, May 28,
2004 1:57 PM
To: Lancair Mailing List
Subject: [LML] Legacy exhaust
After about 4 hrs on N121J, it's
clear that it needs exhaust modifications. The straight exhaust tubes
supplied by Lancair come out too close to the skin. The exhaust gas
stream appears to be flowing along the skin for about 3 or 4 feet before mixing
with enough of the airstream to cool it. If I keep flying with it as is,
the paint will start to blister and I'm afraid I might even see delamination.
The factory suggested simply
opening up the rear of the cowl exhaust tunnels and deflecting the exhaust
pipes downward. Bad idea, since the ball joints won't accommodate that
much bend without leaking. For some reason, the ball joints were pointed
straight back, more or less level, instead of angling downward toward the
exhaust tunnels.
The short exhaust tube sections
can't be bent -- they don't fit into the usual benders for auto exhaust
pipes, and in any case, the thin-walled stainless they're made of would
collapse unless a mandrel bender is used. One solution would be to have
an aircraft exhaust company make new ones, which would undoubtedly take quite a
while and be expensive. What I've done instead is to order a U-bend piece
from Borla (www.borla.com) that
consists of a 6-inch radius, 180-degree section, with 8" legs, all in
2-1/2" diameter T-304 stainless (Borla part number 19250). I'll
bevel the ends of the legs, then cut so that I have a 20-degree curve section
on the other end. I've cut the exhaust pipes off 10" from their
ends, and found a gent locally who can weld the thin-wall stainless.
This ought to bring the open ends
of the exhaust pipes several inches lower and farther from the skin.
Perhaps newer exhausts supplied by Lancair are different, but if yours are like
mine, think about getting the exit ends well away from the belly of the airplane.
With any luck, the noise level inside might even be reduced a little.