Need a box shaped nosebowl

On Feb 4, 12:30*pm, DonMorrisey wrote:

Howdy,
Where would I find these "blister fairings"??...

You make them, using any of a wide variety of tools, materials, and
methods. My favorite method for small blisters is to constrain a nylon
or Visqueen membrane using double-sided tape and whatever else is
handy, inflate it with a few PSI of air, and lay up a few plies of
fiberglass over the resulting bulge. Fill to shape, file to fit, sand
smooth, and paint to hide.

...Although I have a feeling the interference is too significant to cure
with those. *Just giving it the eyeball test both lower left and right
sides would have to be cut from the nosebowl and somehow a boxier
shape created...

Are we just talking about just the fiberglass MC-3 nosebowl here, or
are we talking about the nosebowl and lower cowl? I am hard-pressed to
see how any exhaust on an O-235 would get very far outside the
envelope of just the MC-3 bowl.

I suspect that what you might mean is that the exhaust system gets
outside the envelope of a lower cowl that would be formed by a ruled
surface extended between the lower half of the MC-3 nosebowl and the
firewall. Is that it, or am I off-base on that guess?

Looking at this picture of your engine, I can see that the PowerFlow
system is indeed a pretty tall exhaust system:

http://www.donsbushcaddy.com/sitebui...ingO235L2C.jpg

That's one of the reasons I was never a particular fan of the
PowerFlow. Their installations seems sort of clunky, and they have
that huge muffler hanging way out in the breeze. I'm far more partial
to the Vetterman systems common on the RV-series airplanes:

http://vettermanexhaust.com/

Thanks, Bob K.

I suspect that what you might mean is that the exhaust system gets
outside the envelope of a lower cowl that would be formed by a ruled
surface extended between the lower half of the MC-3 nosebowl and the
firewall. Is that it, or am I off-base on that guess?

Bob,

The quote above is exactly the problem, hence the need for a more
rectangular nosebowl. So what I'm really after is direction on where
I may find a nosebowl that isn't crescent shaped on the bottom???

Thanks. Don...

On Feb 4, 5:02*pm, DonMorrisey wrote:
So what I'm really after is direction on where
I may find a nosebowl that isn't crescent shaped on the bottom???

Ah, right. I'd start by looking at other airplanes that use that
particular model of exhaust system, and see what they use for a
cowling. It might be that the nose bowl of a PA-28 would fit, I seem
to recall it as pretty tall. If something like that doesn't work, you
will probably end up making an entire cowling, including nosebowl,
from scratch or nearly so.

Well, that's not actually what I'd do. I'd probably flog that exhaust
system on eBay and go with a different system that fits into a tighter
cowl. I just don't see the point in adding so extra frontal area and
volume to the cowling for an exhaust system with little if any benefit
over other systems available for experimental airplanes. But that's
just me.

Thanks again, Bob K.