Jeff Spitzer wrote:

Tracy Crook wrote:

This is neat stuff Paul, I had no idea the P47 was plumbed that way.  This
is the approach I plan to take with the turbo charged 13B powered RV-8 I am
planning.  (I've decided against the 20B)   The distance will be
considerably less than on the P47 but still far enough away for the flames
to die down before the turbo.   The EGT is my only reservation concerning
turbo operation of the rotary.

Yes, I have heard the stories about the exhaust being hotter the further

out

you go on a rotary but I think these are racing stories with engines

running

very rich mixtures.   I haven't proven it yet with instrumentation but the
header pipes on my RV-4 show evidence that  the exhaust cools off after
about 18 inches at the lean mixtures I typically run at.

The issue is not so much mixture but flame quenching in the corners, edges,
etc.  I'm sure you know this and a very lean mixture will only improve it
slightly because basically you are burning the "mixture" that was
previously quenched by the walls.  I would say that the exhaust temp does
go up in the first foot or so and then begins to drop pretty rapidly if not
insulated.

 BTW,  my 321 stainless exhaust system (all .035 wall tubing) is still
working after 800+ hours.

HOORAY!!!!!  I have quietly sat back while Paul preached inconel.  I think
inconel is a good idea but I also think that a properly done stainless
system will be satisfactory.  .035...WOW!

Jeff Spitzer

Don't get your hopes up too high that stainless is going to work
with a turbo charger. Maybe if the turbo charger is in the aft
fuselage. Tracy's may still be working but they are corroded real bad
and ugly last time I looked at them :-) I think that corrosion is 
what is holding them together :-)

Paul Lamar
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org