REFLECTOR:Baffling, CHT, EGT, Ehxaust Wrap ...

Brian Michalk reflector@tvbf.org
Mon, 10 Nov 2003 10:07:09 -0600


> -----Original Message-----
> From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
> Behalf Of Scott
> Sent: Monday, November 10, 2003 8:22 AM
> To: reflector@tvbf.org
> Subject: Re: REFLECTOR:Baffling, CHT, EGT, Ehxaust Wrap ...
>
>
> Jim,
>
> Have you read "The Pelican's Perch" articles about LOP operations? If not

I love that guy.

> IO360 with stock injectors and two mags, I couldn't lean to 50 LOP, after
> installing the light speed I can now lean to 100 LOP if all my plugs are
> pretty clean.  You might have to get Gamijectors to run LOP.

Assuming they are clean to begin with, how clean do they run?  I'd imagine
that they have that nice creamy brown color.  Is this what you are seeing?
Are you running aviation plugs, or auto plugs?  What reach (heat)?

> 50 LOP when you see the temps rise?  When experimenting and
> learning about
> LOP be sure to do it at 8000 ft or above so you don't have to worry
> about  detonation problems.

Just to clarify here:
What he means is: 1) make sure you have fairly low manifold pressure.  Get
up to altitude where the air pressure is low, and the air temps are cool to
prevent detonation.
2) Don't lean under high power operations.
3) Don't linger in the peak EGT region.  Lean up to peak, note where that
is, then lean right past it.  I would keep going till the engine stumbles,
and see how all of your cylinder EGT's match up.  You want them to peak
together so that when you do run lean, you know that none of them are
running at peak.

> As far as the exhaust wraps, I tried em and they didn't help at all.  If
> your pipes are made of "really good" stainless, they probably won't hurt,
> if not they will corrode  very fast from the heat and moisture
> cycle. Tight
> baffling is the key as you are finding out.

This is my major concern.  I've welded my own exhaust manifold for the
turbo, tried to keep as little force on the manifold as possible to prevent
cracking, but it's my first time doing something like this.  I wonder if
ceramic coating inside and out would prevent corrosion?  But then one
wouldn't need to wrap, would he?
I made the manifold out of 321 .035 stainless.  If it weren't for the
weight, I'd make it out of .065.  I'm so much better at TIG now than when I
first started.  I think my first project after I get flying is to make
another exhaust manifold for when my current one cracks.

Of course, if I could afford or machine (or find a source) inconel...