Dog house to silicone baffle?

[DXB]

31 minutes ago, Sabremech said:

Cowling project is back to making progress. I’ll have two different cowlings as a result of the issue I had with the prototype. I now have a full forward fuselage along with an engine to fit parts in my shop. That was a big set back when I sold my C to Don!! 
 

That's great.  Any mention of progress on this project brings holiday cheer to the hearts of C model owners.

[DXB]

2 hours ago, Shadrach said:

What is the reasoning for having an inner plenum? Do all of the E models have a Doghouse? Just curious why my 67F just uses the upper cowling as a plenum but Hank’s 70 C has a doghouse.

I'm pretty curious about this question too.  The carb'd C models with their plenum baffles seem to cool exceptionally poorly, yet Mooney never moved away from this design.  The I0-360 Es and Fs seem to cool much better whether they have the doghouse (in at least the old Es, not sure about the newest ones) or not (the Fs).  

[David Lloyd]

2 hours ago, Shadrach said:

Don’t most RVs have a fiberglass plenum? What is the reasoning for having an inner plenum? Do all of the E models have a Doghouse? Just curious why my 67F just uses the upper cowling as a plenum but Hank’s 70 C has a doghouse.

Van’s plans and most built airplanes have baffles. Some build plenums of their own design. One aftermarket cowling supplier also sells a plenum.

i think all A to G Mooneys thru 1967 had the dog house. Sometime soon after the F was introduced, the E and F began with the open baffles.

[Shadrach]

1 hour ago, David Lloyd said:

Van’s plans and most built airplanes have baffles. Some build plenums of their own design. One aftermarket cowling supplier also sells a plenum.

i think all A to G Mooneys thru 1967 had the dog house. Sometime soon after the F was introduced, the E and F began with the open baffles.

F was introduced in MY1966. No F came with doghouse as far as I know. 

[Guest]

5 hours ago, Shadrach said:

Don’t most RVs have a fiberglass plenum? What is the reasoning for having an inner plenum? Do all of the E models have a Doghouse? Just curious why my 67F just uses the upper cowling as a plenum but Hank’s 70 C has a doghouse.

They never came from Vans with a plenum.  Many who’ve done the conversion use a Sam James system.

https://www.jamesaircraft.com/products/plenums/

[Sabremech]

The IO-360 I’ve worked on and did my mods to pretty much never see above 375 on CHT’s when it’s hot out. I attribute that to the IO cylinders being bigger and more cooling fin area along with the better burn of fuel injection versus carb. 
The O-360’s that I modded seem to do better with the tighter baffles along with the same air inlet area as the J model cowling has. That’s what I’m doing with my cowl for the C & G. It will have the same air inlet area as the J. Still trying to decide the best and most cost effective baffling for the C & G. The IO baffling is the same as the J and I have a complete set to make patterns off of. 
I’m  going to do some research on the Husky that I have access to as it’s a 180 horse and pretty much identical to our C & G engine wise. We don’t see that hot of temps in it as seen in the carbed Mooney.

Thanks,

David

Edited December 12, 2022 by Sabremech

[vik]

I am going thru the change right now. Will report when done.

As the consequence, I have the pieces for the dog house for sale if anyone is interested.

Vik

[FlyingDude]

On 12/11/2022 at 5:04 PM, vik said:

I am going thru the change right now. Will report when done.

As the consequence, I have the pieces for the dog house for sale if anyone is interested.

Vik

do you have an STC or how are you logging the change?  Thanks.

 

[vik]

On 1/3/2023 at 12:43 PM, FlyingDude said:

do you have an STC or how are you logging the change?  Thanks.

 

M20E of the same model year came with baffling. Same airframe, engine, cowling, prop etc == Just a log book entry.

[FlyingDude]

30 minutes ago, vik said:

M20E of the same model year came with baffling. Same airframe, engine, cowling, prop etc == Just a log book entry.

I was pursuing this and even contacted Mooney tech center. I showed them how the manual shows that my 67 E should have open style (J style) whereas it has the doghouse. I documented how the engine and top and side cowls are the same as an F, which has the J style open cowls. MTC only responded that my plane's original TC listed doghouse baffle part numbers, along with the cowls and engine that I have... He also noted "I don't see any other part number." 

So I gave up.

In the meantime, I smeared red RTV like there's no tomorrow, plugging the strips between the oil cooler (rear mount) and baffles, as well as any hole and oil temp dropped a bit. I can now climb 15 kts slower in the summer at the same CHTs. 

Is your statement your own logical deduction or are you quoting an IA? I would still like to make the switch when my baffles will eventually require replacement. 

[47U]

4 hours ago, FlyingDude said:

I was pursuing this and even contacted Mooney tech center. I showed them how the manual shows that my 67 E should have open style (J style) whereas it has the doghouse. I documented how the engine and top and side cowls are the same as an F, which has the J style open cowls.

 

Perhaps if you showed your research to your A&P/IA they would approve it as a minor mod?    

[DCarlton]

On 12/6/2022 at 10:15 AM, Hank said:

I don't know how many Cs have doghouse, but this is the original cowling on mine. While @Sabremech's conversion is appealing, I don't want to give up the large removable cheeks on both sides. Taking off the.lower cowl is something I've done once since 2007, and i don't want to have to do it every oil change or annual!

That’s how SWTA did their cowl mod.  It gave you the J cowl style but kept the two cheek panels.  I like that feature too.