Are these gaps in my baffles normal?

[peter]

We have about a 50 deg temperature difference between hottest and coolest cylinders in our 82 231, and I'm trying to figure out if this is "normal" for the notoriously hot running TSIO36-LB engine in this model of Mooney. 

Last time I had the top cowl off I snapped some photos of some gaps where the aft metal baffling goes around the engine case. 

The first picture is the aft left side of the engine behine the oil filler neck. The second picture shows the baffling around the case behind the right rear cylinder. 

Are the gaps in these pictures "normal" or should these have been filled with the same RTV I see elsewhere in the pics?

Many thanks,

Peter

[Jeff_S]

i can't speak for the baffling, but I know at least in a NA engine the degree spread of CHTs can be that much as long as your upper temps aren't getting into the dangerous zone. It's been mentioned before in these pages, but for a great examination of EGT/CHT readings and how to interpret them, go to Savvy Aviator webinar series. Here's the direct link:

http://www.savvymx.com/index.php/all-about-egtcht

[Geoff]

Peter,

I will look at my baffles today and let you know.  I am also running an '82 231 with a merlyn and intercooler.  The engine was originally a TSIO360-EB converted to an LB (don't ask). 

I too have a large temp spread between hottest and coolest cylinders.  The hottest cylinders tend to be #5 and #6, the coolest are #1 and #2.  In cruise (2500/28 in, cowl flaps closed, 11.7 gph, stock injectors) temp spreads can be 50 deg different.  I have a Insight engine monitor so everything is in 25 degree increments, so precision about temps is hard. What engine monitor are you running? Which cylinders are you seeing the biggest differences? 

I also have a "gami" spread of 1.3 gal and choose to run 100 deg ROP (and no I'm not baiting you into a discussion of ROP/LOP) Just though it would give you a sense of the fuel system setup.  At my last annual (last month) when they had the fuel injectors out to clean them I had them switch the injectors on 1-6 and 2-5 to try and get more fuel to the hot cylinders.  We'll see if this improves the situation any. 

[scottfromiowa]

Geoff.  You need a new Insight G3.  Plug and play for under 2 AMU's.  Check it out.  Appears to be the best leaning instrument out there...as well as proving detailed (color bars and temps).  You can use your same probes and it fits the same hole in panel.  I am there when they come out after 1/1/11.  Per Insight rep comes with ALL probes so you can have non-primary indications of fuel flow, tach, MP, outside temp, Oil temp etc....

[flight2000]

Scott,

Where are you finding the GEM G3 for under 2 amu's?  Everywhere I've looked, the price was closer to 2.5 amu.  I'd love to go color over the UBG-16, but price is important right now. As you know...

Thanks,

Brian

[peter]

Quote: Geoff

I too have a large temp spread between hottest and coolest cylinders.  The hottest cylinders tend to be #5 and #6, the coolest are #1 and #2.  In cruise (2500/28 in, cowl flaps closed, 11.7 gph, stock injectors) temp spreads can be 50 deg different.  I have a Insight engine monitor so everything is in 25 degree increments, so precision about temps is hard. What engine monitor are you running? Which cylinders are you seeing the biggest differences? 

[Geoff]

I have the same gaps in my baffles as you do.  I don't know if this is "normal" or not.  I find it interesting that your middle cylinders are the hot pair.

[jlunseth]

50 dF is not abnormal in the 231.  I am a little puzzled by the posts talking about 1 and 2 being the coolest running cylinders.  In the Continental TSIO-360 #'s 1 & 2 are the rearmost cylinders, not the front cylinders.  They are the front cylinders in a Lyc. I believe.  So 1 & 2 tend to run hottest because less air reaches them.

[richardheitzman]

from those pics the baffles are fine.