Strange baffle on M20C

[finnicky7]

My mechanic has been working on lowering my CHTs and wasn’t fond of these. They were between my 1/3 cylinders and 2/4.  Very thin aluminum.  They have been removed to see if cooling gets better.

Anyone seen these?

[Sabremech]

Definitely home made and not stock. 

[Bunti]

It looks like that already somebody before you  tried  to modify the standard airflow to alter the cooling of the cylinders of your Mooney.

[47U]

28 minutes ago, finnicky7 said:

My mechanic has been working on lowering my CHTs and wasn’t fond of these.

That looks like some serious eyeball engineering… crazy.

A PowerFlow exhaust STC?  Have you checked the carb to make sure it is the higher fuel flow part number?  There’s a thread on that somewhere.  Here’s one, from 10 years ago….

And finish your baffling repair initiative.  

What year C… fixed cowl flaps?  Has anyone ever installed the louvers in the side cowl panels that you see with aftermarket turbocharger installations on C models?  That would increase outward airflow (I’d think).  

Keep us posted… good luck.

[hammdo]

Wouldn’t there be lower baffles? Seems they are missing…

-Don

[N201MKTurbo]

They should have the Lycoming inter cylinder baffle. New ones are not crazy expensive.

[cliffy]

Look in the Lycoming and the Mooney parts manual to see if you have all the correct baffle parts you need

before you get too deep into spending money on chasing an issue that can be solved with the correct parts

Verify what the book shows to what you have part by part.

[47U]

Timothy… is it too late for nit-picking?  

Adjustable cowl flaps (62C?)… you might benefit from exceeding the book spec of 1.1” by a skosh, if your A&P allows.

Did someone replace your doghouse tinnermans with rivnuts?  Rivnuts has a little shoulder to them, potentially leaking some air?

Is that red RTV on the intake and exhaust gaskets?  Curious.

Intake tubes wrapped with exhaust header tape?  Curious.

What is that tube running aft from the #4 rocker box oil drain tube, it’s routed outboard of the #4 exhaust stack.  It’s smeared with something?  Am I seeing things?  Is that the starter cable?

I see what appears to be some FOD in between some cylinder fins on #3.

Is there a SureFly mag along with the PowerFLow exhaust?

I’m crawling back into my hole… you really don’t have to respond to any of this if you don’t want to.  Thank you.

[Greg Ellis]

As has been mentioned, make sure you have all the parts for the Doghouse.  I can see that you do not have the inter cylinder baffles as @@N201MKTurbo has mentioned.  They are quite important for proper cooling.  If you had them we would see the the hook that hooks from the top of the cylinders down through to the underneath side where the baffle is.  Also, make sure you have the connecting tie rod along the bottom.  It holds a front piece of the baffling to a rear piece of the baffling and keeps them tight around the cylinders.  It is amazing what a difference it makes in cooling just to have those tight around the cylinders.

[finnicky7]

18 hours ago, 47U said:

That looks like some serious eyeball engineering… crazy.

A PowerFlow exhaust STC?  Have you checked the carb to make sure it is the higher fuel flow part number?  There’s a thread on that somewhere.  Here’s one, from 10 years ago….

And finish your baffling repair initiative.  

What year C… fixed cowl flaps?  Has anyone ever installed the louvers in the side cowl panels that you see with aftermarket turbocharger installations on C models?  That would increase outward airflow (I’d think).  

Keep us posted… good luck.

• 1962 M20C
• Non-fixed cowl flaps
• Have not added the louvers
• Thank you!

 

[finnicky7]

3 hours ago, 47U said:

Timothy… is it too late for nit-picking?  

Adjustable cowl flaps (62C?)… you might benefit from exceeding the book spec of 1.1” by a skosh, if your A&P allows.

Just talked to A/P about this.

Did someone replace your doghouse tinnermans with rivnuts?  Rivnuts has a little shoulder to them, potentially leaking some air?

Not sure.

Is that red RTV on the intake and exhaust gaskets?  Curious.

Yeah we found some homemade terrible ones. Now has OEM with RTV.

Intake tubes wrapped with exhaust header tape?  Curious.

Previous owner.

What is that tube running aft from the #4 rocker box oil drain tube, it’s routed outboard of the $4 exhaust stack.  It’s smeared with something?  Am I seeing things?  Is that the starter cable?

Not sure on tube, I'll look it over, the goop was RTV they used all over to hold the Franken-Baffle.

I see what appears to be some FOD in between some cylinder fins on #3.

All cleaned now.

Is there a SureFly mag along with the PowerFLow exhaust?

Yes on both.

I’m crawling back into my hole… you really don’t have to respond to any of this if you don’t want to.  Thank you.

THANK YOU!

[DXB]

21 hours ago, finnicky7 said:

My mechanic has been working on lowering my CHTs and wasn’t fond of these. They were between my 1/3 cylinders and 2/4.  Very thin aluminum.  They have been removed to see if cooling gets better.

Anyone seen these?

Super weird home-made stuff that is not helping you at all.  This pic  is giving me a headache. Several of the points have been made already:

-the need for inter-cylinder baffles; the (missing?)

-?missing tie rods on each side of the the bottom of the doghouse (2 per side)

-the stuff wrapped around the intake risers

-the ?missing heat shield between the #4 exhaust and the bottom cowl support strut

-?RTV on exhaust gaskets?

-whitish discoloration on cylinder head next to #4 exhaust port - just heat related paint changes or exhaust leak?; 

Note the doghouse sucks and needs to be in near perfect condition to get half way decent cooling.  Get that addressed first. Consider retarding timing to 23 from 25. Make sure you have the richer carb model for this engine and  get at least 18gph at sea level takeoff.  Highest CHTs for my takeoffs didn't become consistent manageable (<<420) until I got a new carb with my overhaul.

Note the Powerflow on the O-360-A1D gives a decent power increment, but that also means more heat.  If you have a Surefly mag set to variable timing it gets even worse in cruise at least.   

[Sabremech]

I think the inter cylinder baffle is there. It’s in the picture with the OP’s finger. Look back behind the homemade divider. As for RTV on the exhaust gasket, just did that with a new exhaust on a J model. Can’t hurt and I’ve had issues in the past with the anti blow out gaskets.

David