Ok Guys here goes, With all this exhaust talk nobody has
mentioned
titainium.
Before everyone goes loopy on me, let me mention that I have an
all
Ti
exhaust on my gsxr Suzuki. While this exhaust was far from
cheap,
(retail 1500 bucks,) there are some real advantages. First; Ti
doesn't
corrode. It is similar to 300 series stainless in that reguard.
Second;
Ti has high temperature resistance, it's actually stronger at
temp.
Lastly;
it is so light IT IS AMAZING. My entire 4 into 1 exhaust system
including
the muffler weighs 7 pounds. Welds similar to stainless. The
exhaust
on
my bike is at least as complex as the Racing Beat turbo one if
not
more
so. seems like we could make a good tangential or VAM out of it
for
less than the inconel systems. Tubing is available. What do you
guys
think? Bill Jepson
Bill,
So what would be the cost and weight of a Vam muffler in Titanium as
compared to the Stainless Steel or Inconel (i.e. a rough cost
benefit
analysis).
A question on the Ti - if it gets stronger with heat does it act
like
6064
Al whereby the Al gets harder as it is artificially ages with heat,
or
is it
a cyclic thing and if cyclic (ie hard then soft), would that induce
cracking
at welds etc.
George (down under)
Paul
Dean wrote:
IIRC, there was very extensive use of titanium in the aft fuselage of
the
McD F-4 aircraft. The "shingles", for lack of the proper term, and
even
the aft part of the keel were all Ti.
Dean
Paul Carey wrote:
Paul
Exhaust material comments:
Turbine combustion chambers are different to piston/rotary engine exhausts,
and often have a layer of air between the flame front and the liner (some
liners are only .020" thick). The most severely punished in my 20 years as
an aircraft engineer are turbocharged twins - Chieftains, Cessna 400 series
etc. The exhausts glow orange in normal cruise. The exhaust material is
inconel I think, and with quality design and manufacture (certified TIG
welding) and regular 50 hour inspections, there are no real problems. On
inspection, I usually look for the molecular change (goes magnetic) and for
blistering/cracking. Standard practices apply to assembly and hardware of
course. I guess for you guys, it is the design that would be critical -
ensuring bend angles/thickness and expansion allowance are right. I have
seen some pretty ordinary designs and manufacture in the home built field
here in Australia.
Best link for materials and material information including exotic off the
shelf items http://www.burnsstainless.com/index.htm
Regards
PC
Paul Carey LAME, MC
Aero Management - aviation consultants.
www.aeromanagement.com.au
(08) 9371 5205 0418 959 892
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