REFLECTOR: Exhaust Questions Need durability and HP

[Sid Knox]

Several years ago I had a pipe break clean off.... only the safety wire kept 
it from going thru the prop.  It made a lot of noise banging against the 
cowling but I had only about 10 minutes flight to get back home so it could 
have been worse (the wire would have broken after a while).  Actually, the 
scary part was when the exhaust flame inside the cowling melted  the aileron 
control cable and essentially froze-up aileron movement.  Luckily, I had a 
straight-in, no wind so the plane was conrtrollable with rudders. Until I 
landed and looked, I had no idea what was going-on... just that I wanted it 
to never happen again.  It was a crappy design that had that "U" hanging out 
there with no support.  It thought it was a tuning-fork and was only a 
matter of time before it broke at the weld.  I modded both pipes as shown 
and added a second safety cable held to the pipe with a SS hose-clamp. 
Several hundred hours later and no more pipe breakage.

Not exactly what you were asking about but somewhat on-topic.

Sid Knox
Oklahoma

Velocity  173 RG  N199RS
Starduster  N666SK
KR2         N24TC
W7QJQ

----- Original Message ----- 
From: "brent bourgeois" <bjb3013 at yahoo.com>
To: <reflector at tvbf.org>
Sent: Wednesday, November 29, 2006 6:24 PM
Subject: REFLECTOR: Exhaust Questions Need durability and HP


>I have a few questions about the exhaust on my Lyc
> IO360 powered Std RG. I have the rear pointing
> stainless pipes from Velocity. The co pilot side (the
> long side) gets cracks every 60 to 100 hours right
> behind the #2 junction. No welds have cracked, always
> the pipe wall. This pipe has been trimmed as short as
> possible and still get past the fairing.I always have
> at least 2 pieces of thick safety wire on both sides
> to hold everything in in the event of total breakage.
> Is this normal?
>
> Why do the new pipes face forward? Why do I want all
> of this heat in the cowling. Do they have a long side
> and crack like the rear pointing pipes. Do they have
> slip joints? Why not weld up a set that drops straight
> down ?  Four pipes could be used or a 2 into 1
> pointing down. If the pipes point outward slightly
> they would not be over 12 inches long, possibly much
> shorter.
>
> I was told at the symposium that the standard Velocity
> pipes cost 2-6 horse power on a dyno. What size is
> optimum for the drop pipe and the tail pipe?
> Are any drawings available with dimensions to build
> your own. What type of stainless are the factory pipes
> and what thickness are they (would thicker help)
> Should I use 304 or 321 stainless.
>
> Thanks ahead of time for help with my project
> Brent
> 985-785-8299
>
>
>
>
>
>
> ____________________________________________________________________________________
> Do you Yahoo!?
> Everyone is raving about the all-new Yahoo! Mail beta.
> http://new.mail.yahoo.com
> _______________________________________________
> To change your email address, visit 
> http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw > Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
> 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.tvbf.org/mailman/private/reflector/attachments/20061129/eed33696/attachment.htm 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: exhaust pipe  composite_c50.jpg
Type: image/jpeg
Size: 129451 bytes
Desc: not available
Url : http://www.tvbf.org/mailman/private/reflector/attachments/20061129/eed33696/attachment-0001.jpg