SWTA vs normal cowl cylinder baffling?

[garytex]

First off let me say that I think you have a wonderful forum here.  Second, I am thrilled to now finaly have a Mooney. It only took 20 years and two other airplanes.

My question.  My SWTA cowl seems shy in the provision of baffles to wrap the bottom of the cylinders, particularly the front half of the front cylinders.  I called Rus, and no, thats all they certified it with.  I was wondering what experience others might have had with that or the MAC cowl cylinder baffling.

 

Thanks, Gary 

[Ron McBride]

Gary

I created a picture for you, that is typical for my 69F. I am not an artist. Please see the Photo galleries, or my picture gallery.  N9154V

Hope this helps.  

Ron

[garytex]

Ron

Thanks for the picture.  What you show is what I expected to see and didn't.  The missing pieces are the bottom wrap from the front of the front cyl. and the safety wire running back and holding it and the back wrap comming forward, and holding both tight against the bottom and redpective sides of the cyls.  We may need a visit from the mooney baffle leprechaun.

Thanks, Gary

[DaV8or]

My understanding is that the baffling for the SWTA 201 cowl mod is largely copied from the factory 201 cowl baffling. It's not exactly the same, but close. Question is, does the J have this inner cylinder baffle you're asking about? I have the SWTA cowl and don't have it. I have no cooling problems that I know of.

[garytex]

I do not know about the J, but that would be another example, and we know that is a successful engine installation.  Maybe someone with a J will wander over into Vintage, looking for used jeans or a vinyl and chrome chair, and illuminate things for us. Either that or we will have to get off our behinds and physically go look at one, blogven forbid.

[KSMooniac]

The J does indeed have pieces that wrap below the cylinders at the forward and aft ends, and are "tied together" with a baffle spring that keeps them tight against the cooling fins.  

[jetdriven]

We have those lower wrap baffles and a wedge intercylinder baffle as well.  CHT even with brand new seals etc can still get above 365 f. 

[garytex]

Yes, that looks like just what the baffle leprechaun ordered.

Thanks so much, Gary

[DaV8or]

Quote: DaV8or

My understanding is that the baffling for the SWTA 201 cowl mod is largely copied from the factory 201 cowl baffling. It's not exactly the same, but close. Question is, does the J have this inner cylinder baffle you're asking about? I have the SWTA cowl and don't have it. I have no cooling problems that I know of.

[garytex]

Yes, we've both got the inter-cyl. baffle between front and back cyls. that hangs from the support bar across the barrels.   The parts I do not have are the front and back barrel and head wraps.  There are several additional pieces that protect the front side of the front head from direct ram airflow, and force the cooling air to wrap around the cyl. barrel before it and escape into the lower cowling.  Air Salvage of Dallas is having a sale this weekend, the baffle leprechaun and I may wander up there and see what we might find.  Poof

Gary 

[garytex]

The baffle leprechaun has been busy, but not quick enough to help save Cyl #2 which was fouling a plug, because it was (unpleasant surprise) pumping oil, and a borescope inspection showed a polished longitudinal stripe on the cyl wall.  When pulled, the stripe wouldn't catch a fingernail, but the piston skirt was all coked up and when sent to Custom Airmotive they found a crack in the head too large to weld.  O how I hate exchange overhauled cylinders out of a small expensive population that are liable to get reused too many times.  I now have another one of those, maybe better, a Cerminil Titan.  With the new intake tube that actually has a full flange to seal, and decent baffles, maybe this jug will last a while.  Repairs for this little expedition on top of curing all the pre-purchase squawks have now cost $750 / hr for my first 10 hours of ownership.  Need to go fly some more to get the cost down.

So I wonder what trashed the jug?  The intake leak, the lack of baffling, all the takeoff and landing practice I did transitioning, or was it just a worn out old overhauled jug to start with when installed 200 hrs ago? All of the above?   I also wonder if, unless we have pretty new jugs, if we aren't all flying around with more cracked heads and cases than we realize.  

Gary 

 

 

 

[jetdriven]

Running 50 ROP with an induction leak will trash a cylinder in no time.   

 

Do you have a 4 point cht or an engine monitor?  

[garytex]

Jetdriven

Yeah, that how the previous owner ran it.  

Yes, have a monitor, and I noticed the higher egt in the last hour or two of flight.

You pay a lot of attention, what do you think is the correct multiplier to determine hp and % of power LOP.  Or is the way to do it by fuel flow to the POH or speed to the POH ? 

Thanks, Gary

 

[danb35]

For the IO-360-A1A, with an 8.7:1 compression ratio, you'd be looking at 15 x fuel flow to yield HP when LOP.

[Shadrach]

Quote: jetdriven

Running 50 ROP with an induction leak will trash a cylinder in no time.   

 

Do you have a 4 point cht or an engine monitor?  

[Shadrach]

Quote: jetdriven

We have those lower wrap baffles and a wedge intercylinder baffle as well.  CHT even with brand new seals etc can still get above 365 f. 

[Shadrach]

Quote: DaV8or

My understanding is that the baffling for the SWTA 201 cowl mod is largely copied from the factory 201 cowl baffling. It's not exactly the same, but close. Question is, does the J have this inner cylinder baffle you're asking about? I have the SWTA cowl and don't have it. I have no cooling problems that I know of.

[jetdriven]

Nice catch!   Yeah I noticed that in the photo, last week was the annual inspection. I pulled it down some. It was rubbing.   That forward wrap baffle broke a couple weeks ago and the all-thread piece fell down and chafed the alternator aux wire. 

Quote: Shadrach

Byron, I'd adjust that cylinder drain tube or at least put some RTV between it and the lower baffle. It looks like it will chafe...