REFLECTOR: High Temps

[Ronnie Brown]

Welcome Aboard!!!

Have you checked your injectors?  You could have a plugged or defective
injector on number 4.

Ronnie Brown
Cornelius, NC


----- Original Message ----- 
From: "Gary Ciampa" <Gary.Ciampa at sas.com>
To: <reflector at tvbf.org>
Sent: Wednesday, January 12, 2005 10:29 AM
Subject: REFLECTOR: High Temps


> NOTE: First Time Post,Happy to be Here! <G>
>
> Jim,
>
> I'm flying a 173 FG, IO-360-C1D6 and have *recently* experienced the same
high temperatures as you observe on Number 4. Running above 75% power and/or
any attempt to lean, shoots the number 4 cylinder up to 450F pretty quickly.
A short bit of history, not to bore anyone but to provide a bit of context.
>
> I purchased the airplane in May of 2004 and had need to replace the
exhaust stack. The original configuration was updraft cooling, rear exit
exhaust, cylinder wraps around each cylinder head/barrel, fore and aft with
a reverse scoop in the top cowling above Number 4, I also have two VG's in
front of the NACA scoop on the right side only. In reviewing the logs and in
discussions with the former owner, cooling number 4 has always been watched
closely.
>
> In replacing the exhaust stack I made the decision to switch to the
forward facing exhaust (at this point, I'm not sure if this was the correct
decision, I'll know when the cowling work and temperature problems are
corrected). In any case, with the new exhaust in place the temps on Number 4
are high, once again.
>
> The changes to the cowling included cutting holes near the NACA scoops for
the forward exhaust exit, cutting out the fiberglass shrouds for rear exit
exhaust and six layers of BID layed in to cover the holes for the old
exhaust scheme. Also, fabricated a scoop in the cowling under the exhaust
for Number 1, as this bend in the exhaust pipe extends below the cowling
about three-fourths of an inch.
>
> Our current *theory* on how to correct the temperatures on number 4
include:
>
> 1. Remove the inner cylinder baffles that wrap between Number 2 and Number
4, with a stock Lycoming Intercylinder Baffle. This will allow more air to
flow up through the cylinder heads (I will note that other posts seem to
indicate no problems with having these baffles between number 2/4.)
>
> 2. Experiment with deflectors along the inside bottom of the lower
cowling, perpendicular to the longitudinal axis, in the vicinity of Number
2. The theory being that we can buffer the cooling air in front of Number 2,
creating additional pressure so that air will be forced through Number 4.
>
> NOTE: Number 1 and 2 are running cold. Number 3 is within limits(I suspect
that fact that Number 3 temperatures are acceptable may be a result of the
scoop under Number 1 forcing more air up through Number 3)
>
> 3. Finally: replace updraft with downdraft cooling (least attractive
alternative, but recommended by our friends at Velocity).
>
> Of course, the information above is subject to the vagaries of the author
and may not be reliable, time will tell.
>
> Warm regards,
>
> Gary
>
> ----- Original Message -----
> From: "Jim & Sharon Beck" <jsbeck at charter.net>
> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
> Sent: Tuesday, January 11, 2005 10:28 PM
> Subject: REFLECTOR: High temps
>
>
>
>    I have a 173 RG that was completed in 2001 and then not flown until
recently and since I did not build it my questions may seem simple to you
more experienced builders & pilots. It has a newly rebuild IO 360 A1B6 that
now has about 10 hours on it. The 2 front cylinders are running about 425 to
450 and the oil tem is running about 225 at cruise.  Should I be considering
a second oil cooler or might these temps come down as it breaks in. These a
winter time temperatures so it seems when summer comes I'll be over redline.
Anyone help on this or thoughts would be appreciated.
>   Jim
>
> _______________________________________________
> To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html