>
     > 3) The VAM muffler *almost* fit.  The exhaust pipe hits  one of
    the mount
     >
     > tubes, preventing the exhaust manifold flange from seating
    against the
     >
     > engine correctly.  There seem to be 3 possible solutions:
     >
     >    A) Make an insert for the manifold flange which adds appx
    1/4".  Not
     >
     > convinced the bolts are long enough for this.
     >
     >    B) Cut the exhaust manifold pipes & lengthen them so  the  VAM
    moves
     >
     > 1/4" - 3/8" farther away.
     >
     >    C) Cut the VAM exhaust tube & increase the angle  toward   aft so it
     >
     > clears tube.
     >
     >
    Mark,   When I built the muffler, I did it with the engine    mount in
    place.  I had it off and on many times.  It had to be  angled   just so to
    slip it over the flange studs, but it did fit. I have no   ideal  why it
    would not fit now.  Of your proposed solutions, the last  one   would be
    easy to do. Cut through three sides of the exhaust so the   last  side can
    act as a hinge. (It can be cut on a band saw or with a   plasma)  Heat
    with a torch and pull it the position  you want.  I can   send    you some
    321 strips for the patch and also some 347 tig rod (required   to  weld
    321).   Or, you can patch it with 304, readily available    everywhere.  To
    weld 304 to 321, use 309 rod.

      I am very disappointed that you are having difficulties,

      Jerry


We were able to get the muffler over the studs no problem.  The    trouble
was getting it to fit completely against the engine - in this   case,  the
bottom could not touch because the exhaust pipe was contacting the
engine mount.  How thick is the gasket material which fits  between  the
engine & the muffler flange, Jerry?  We were doing a dry-fit, but it
didn't seem that close to fitting -- perhaps you had gasketing  in   there
& it was enough?

Agree that increasing the angle of the exhaust square-tube is the
easiest way to adjust it.  Do you suppose there is any reason to  make
this adjustment way up by the VAM, or could it be done a couple of
inches down (where it will be easier to do)?  The only difference is
that doing it a couple of inches down would put a 'bend' in the    pipe --
can't see that a bend would make any difference.

Mark & Mark

It was kind of loud on the dyno so a bend might help.
Also you might want to weld in a few of these while you are
at it. They are reputed to reduce the noise.

BTW Mark if you use the stock M2 cowl what are you going to
do with the cheeks?

Paul Lamar

Mark,  I agree that the bend will be of no consequence.  As far as
the "silencers" I would wait until  you run it and make a real sound
check.   It would also be possible to "drop in" turbulators   into
the exhaust pipe portion.  If it is too loud put in one or two and
then test.  Keep adding them  until you get the sound you want.  This
is exactly what I intend to do, once the system is bolted to my test
engine.  The turbulators would be made from pieces of SS angle.  You
can put them in a grid to disrupt the exhaust gas flow as is done in
the Spin Tech.     Jerry

Its pretty load Jerry as is. It does have a somewhat mellower  sound  however.

Paul Lamar

Mark,  this is an opportunity if you are willing to do the work.
Without changing anything, test the sound level of the engine.  Also,
check peak static rpm.  If it is too loud, you can add the louvers
and test both sound and performance again.  And so on.  We are so
starved for real data on the exhaust.  Everything we think is
speculation and quite possibly not worth a damn. If  you can,  get
measurements of the exhaust  temp at the flange, inside the muffler
and also air temps entering and exiting  the cool tube.   This data
would be a major contribution.   I think Bob White is planning to do
the same.    Jerry

Don't forget guys this is not your average puppy rotary engine.
It is a 250 HP P-port. I am the only one on here that has actully
heard it run :)

Paul Lamar

Very true and I do not doubt your opinion.  But we need to quantify
what we are talking about!!! I can't believe that I,  Jerry Hey, am
saying this to Paul Lamar. Maybe I popped into some sort of parallel
universe where everything is backward:)    Jerry


Funny Jerry but I don't want to have Mark take it off right away
after the first time he runs it. We have plenty of data on
aircraft muffler systems and they are all around 100 db or greater.
My guess on this one is 110 db. Not load but LOUD!!! :) Each 3 db doubles
the noise.

I think a smaller down pipe would help and make it easier to
get it in and out in the bargain.

Paul Lamar



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