REFLECTOR: Exhaust systems

Jim Agnew reflector@tvbf.org
Thu, 10 Jul 2003 05:27:17 -0700 (PDT)


Acording to the standard rule for EGT probes the
temperature drops about 100 degrees per inch away from the
valve so to get a "1400 degree blast" your prop would have
to be inside the exhaust pipe about an inch from the valve.


Anyone got an IR heat detector that can read the end of the
pipe temperature?

Jim
--- Ronnie Brown <romott@adelphia.net> wrote:
> Not only true with the M/T but also any three bladed
> prop.  No way to clock
> it such that it misses the exhaust, even for 4 cylinder
> IO 360's.  No
> pictures but I saw with my two beady little eyes a
> Velocity and a Cozy, both
> with 360's, both with Performance props, both had charred
> spots on one blade
> of the prop, looked like a wooden match that had burned,
> then extinguished.
> Not pretty.  The Velocity prop was returned to Clark, he
> pronounced it dead
> and unusable.  A two blade can be turned such that it
> misses, but as someone
> mentioned, there are only two positions that a three
> blade can be installed,
> both incur the wrath of the 1400 degree exhaust.
> 
> I have a three blade Catto and forward exit exhausts.  No
> soot on the prop
> but some on the cowl.
> 
> Ronnie Brown
> 173 Elite RG 55 hours
> 
> 
> ----- Original Message -----
> From: "Tom Martino" <tmartino@troubleshooter.com>
> To: <reflector@tvbf.org>
> Sent: Wednesday, July 09, 2003 4:01 PM
> Subject: RE: REFLECTOR: Exhaust systems
> 
> 
> | So is the conclusion truly that we cannot have a dual
> rear exiting exhaust
> system with an MT prop because it will damage the blades?
>  That is a major
> disappointment.
> |
> | -----Original Message-----
> | From: Pat Shea [mailto:xl340hp@yahoo.com]
> | Sent: Wed 7/9/2003 1:45 PM
> | To: reflector@tvbf.org
> | Cc:
> | Subject: Re: REFLECTOR: Exhaust systems
> |
> |
> |
> | --- Jim Agnew <jim_agnew_2@yahoo.com> wrote:
> | > All of this talk about cooking props yet I have not
> | > seen any pictures of a charred or burning prop.
> | This
> | > sounds a lot like an urban legend.  Does anyone have
> | > some pictures?
> | >
> | > Jim
> |
> | No pics but...
> |
> | Rodney Brim and the late Steve Drybread made a
> | serious attempt at a rear exiting exhaust for Rodney's
> | XL (IO-540 w/ 3 blade MT and I think one EI). They
> | tried many different configurations (pipes exiting out
> | the existing cowl openings, pipes exiting back thru
> | lower & outboard openings, pipe tips turned out...)
> | but were unable to prevent the exhaust from damaging
> | the blades. Steve did have success getting a similar
> | engine/exhaust combination to work on the Berkut, but
> | since they run a 2 blade fixed pitch prop there are
> | multiple clocking positions. There are only two
> | positions for clocking the MT on this motor.
> | Also, Scott Swing briefly tried a Berkut style rear
> | exiting exhaust on the XL prototype (IO-540 w/ 3 blade
> | MT) and blistered the prop.
> |
> | Pat
> |
> |
> |
> |
> |
> |
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> 
> 
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=====
James F. Agnew
Jim_Agnew_2@Yahoo.Com
Tampa, FL
Velocity 173 Elite Aircraft Completed