Hey Paul and All,
I don't know if anyone has ever taken a renesis exhaust manifold apart
before but here are some pics of mine. I have a tractor aircraft and
naturally the stock exhaust is pointed the wrong way. I split the welded
seam with a abrasive cut off wheel along the weld. I was very surprised
to see an interior slip-jointed manifold made out of what I believe to
be Inconel.

It was reletively soft and thin, I'm no metalurgist but it
was very interesting. I believe I will turn the thing around and weld it
backwards, naturally the holes line up perfectly. The way that Mazda had
them welded is easy to reproduce.

If you look close at the mounting
flange there is to half circles of what appears to be 321ss spacers that
the Inconel was welded to the flange. Then the outer 321 ss heat sheld
(for lack of a better term) was welded back together over that. I've
taken a porta-band saw and cut all of the bends off at the straight
angles and will start to fab them back together with the help of an
aircraft exhaust welder I know.

it's and experement but well see how it
works. I was very surprised to see just hou thin that inner slip joint
material was. If you try this get extra cutoff wheels it took about an
hour of steady work to get them cut apart. I'll send some picks when i'm
through. I'm just bored and thought it might be an interesting
experement.

Rick in Alaska

PS it sure looked like it was burning clean...

Hi Rick

Nice work cutting the ren manifold up. I contemplated reversing
 the beast as you are doing.

Dad and I used the original in our Glasair SII RG,
there was enough room to do a ~150deg bend and then put
a resonator underneath before heading out through the cowl
 exit. Down side was the reversing the gas flow through a
tight bend, upside was having room for a resonator (not sure
 how much attenuation it will provide) and we figured that
 the back pressure must still be way lower than the original
 in the car. The other down side of our system is weight.
We cut the original manifold off at just down stream of an
expansion joint in the inner sleeve (inconel?) then rewelded
the original flange back on keeping an expansion joint in there.
The rest of the system is stainless.

Steve Izett
Perth Western Australia