It weighs more than separate, unmuffled stacks.
It routes unnecessary heat back against the firewall which makes the
cockpit hotter in summer than necessary.
It has two seams which often do not seal properly over time. If the
Ercoupe cockpit were sealed better from outside air infiltration there
would likely have been elevated deaths from carbon monoxide poisioning.
The muffler, or expansion chamber, requires expensive maintenance over
time.
That's about all I can immediately think of.
The original (65 hp prewar) Ercoupe had unmuffled, separate stacks. So
do Aeroncas, Taylorcrafts and Luscombes.
The Ercoupe muffler was fitted in an attempt to reduce cockpit noise.
It has made, at best, questionable contribution towards that goal.
For you, Hartmut, the European noise standards preclude serious
consideration of unmuffled stacks; but such is not the case here in
America.
At any fly-in I highly doubt anyone would say that the bark of an
unmuffled Alon exhaust system is sufficiently noticeable to be
objectionable to those on the ground, and Alons tend to be quieter in
the cockpit than Ercoupes because of their additional upholstery and
insulation.
Regards,
WRB
--
On Nov 4, 2009, at 03:14, Hartmut Beil wrote:
What's wrong with the original style exhaust system?
Hartmut
