Vintage Mooney Cowling Mod

[cliffy]

One of the better ideas to come down the road in a long while!

Keep it going! Those round inlets look really cool.

[Sabremech]

I think what I'm going to do is continue with what I have going so far that includes the 201 spinner. After I get the STC finished I can come back and do the mod with the original style spinner as an option for anyone not wanting to upgrade to the 201 spinner. It won't be difficult to do, but will take a while to get finished.

Thanks,

David

[N601RX]

The cost of the spinner is probably going to be 1/2 the cost of the finished product. Perhaps someone like this guy can make a replica of the 201 spinner and include it into the stc? He is selling his non certified spinners for under $400 while the 201 spinner is close to $2000. Based on other post on here the last few months they may be a market for reasonably priced 201 spinners.

http://www.cumminspinners.com/company-information.html

[Browncbr1]

I think what I'm going to do is continue with what I have going so far that includes the 201 spinner. After I get the STC finished I can come back and do the mod with the original style spinner as an option for anyone not wanting to upgrade to the 201 spinner. It won't be difficult to do, but will take a while to get finished.

Thanks,

David

Perhaps there is a way to make it a modular design so a collar is added for a 201 spinner and no collar for others??

[Sabremech]

After several weeks of part time work making baffles and remaking baffles, I ordered a set of baffles from Vans Aircraft to cut down the process a bit. I've seen a few RV builders doing this and then incorporating the James Aircraft plenum. There's a bit of a fit issue with the plenum and I'm thinking about making my own with aluminum similar to the original system but with the round air inlets to tie in with the cowling. I think it will be a cleaner installation and no issues of flammability testing of the fiberglass plenum. I'd like to say this is the fun part, but I think fun will come when the prototype is finished!

David

[Wesley brown]

Please make the first one for a A model

[DaV8or]

Please make the first one for a A model

 

Makes sense. Start at the beginning.

[Wesley brown]

It's sure does! I believe that someone said the AB and C models are the same. Hopefully the A model will be included . Since it is a older plane it doesn't get the attention it deserves.

[Sabremech]

I think that 65 and earlier are the same and 66 and later the same. If there's a good demand for the first model STC I complete, then I'll certainly consider doing the other earlier year models.

Thanks,

David

[DaV8or]

It's sure does! I believe that someone said the AB and C models are the same. Hopefully the A model will be included . Since it is a older plane it doesn't get the attention it deserves.

 

Wait a minute. If he makes one for the A, would have to whittle one out of wood for you?

[Hank]

At least it an "A model" and not a "Model A."

[Sabremech]

Here's a picture of where the round inlets will be on the cowling mod. It's interesting to see how different it is from the ARI cowl enclosure and the placement of the air inlets may have a direct impact on the temps I see at takeoff. The ARI inlets are more inline with the base of the cylinder where the new inlets will be closer to the top of the cylinder where more heat is concentrated.

 Now I start to fill in with foam and Bondo to get the shape I want.

 David

[jetdriven]

I've had really good luck with west epoxy and micro for a filler. Unless you are just making a mold then yes bondo is much faster.

[Raptor05121]

This looks very interesting. Good luck with your project.

[Sabremech]

Hi Byron,

 Yep, making a mold. The upper cowl mod is easy to define. The lower cowl I've yet to decide how much of it I'm changing. The carb air inlet is my challenge and I'm thinking of replacing a good portion of the lower cowl with a new skin. It might be all of the skin except for the cowl flaps. Still scratching my head a bit.

 Thanks,

 David

[mike20papa]

David, your work looks great!  Good move having the ARI cowling as a departure point and incorporating the James components.  Joe

[Wesley brown]

If you need a cowl to modify I know fletchair in comfort tx has one. They are grumman people but have a A model for parts.

[Tom]

Hi Byron,

 Yep, making a mold. The upper cowl mod is easy to define. The lower cowl I've yet to decide how much of it I'm changing. The carb air inlet is my challenge and I'm thinking of replacing a good portion of the lower cowl with a new skin. It might be all of the skin except for the cowl flaps. Still scratching my head a bit.

 Thanks,

 David

 

Very interesting to follow this and I hope it works out.

 

I assume that you've tried this, but what happens when you take a stock RV-7/9 aftermarket cowl (e.g. Sam James) and try to compress the cowling over a Mooney that has had its own cowling and baffling removed?  Certainly there would be interference around the intake/exhaust, the nose gear situation would have to be contended with, and the aft end of the cowling would have to be made to fit (and/or extended).  But wouldn't this approach be a little easier?  I've done a fair amount of composite work on the homebuilt side.  If a Part 23 re-write would allow for it, this is the approach that I would take (i.e. I would try to RV-ify my FWF as much as possible).

Just thinking out loud (sort of).  Obviously I don't know what it takes to satisfy the STC gods.

 

[Sabremech]

Hi Tom,

I didn't try to put an RV cowling over the baffling etc. Besides knowing it's quite a bit different, it would be a monumental task to get it STC'd. I'm trying to use as much of the original cowling as possible to keep the cost down and to simplify the STC process. It looks like I'll need to put a new skin on the lower cowl to get the shape I want. The structure and cowl flaps will remain, but the aluminum skin will be replaced with a new skin. Oil cooler and landing light to remain where they are.

I'm building the plugs for molds now and hope to drop them off at the shop in about two weeks. I think I have the carb air box figured out. I'm looking to use the airbox off of a Cessna 177 and put the filter in the left cylinder inlet. With this setup, the plenum is not going to be used.

I'll post a couple of pictures of the prototype cowling when I get the bondo shaped a little more.

Thanks,

David

[Sabremech]

Here's a few photos of the cowling prototype. This is the plug to make the molds. I need to have this finished in two weeks in order to make my May 31 deadline.

David

[M20C]

Looks great...one suggestion;  make the lip behind the spinner extend one inch inward (all the way around) to allow for sagging, leaning or "misplaced" spinners;-0

[BigTex]

Post removed.

[Sabremech]

I took the cowling out to the airport and installed it today. I needed some measurements for the new carb air box. I have no more than 4 inches of clearance between the carburetor and the cowling to work with.

I'm interested to hear any thoughts or comments on what you see so far, good or bad.

Thanks,

David

[Hank]

Wow, a very J-like cowl for a (my?) C. Looking good!

Thanks for keeping the part cost and installation labor reasonable.

[Sabremech]

Hi Jim and Hank,

Thanks for the replies and the comments. Jim, I fully agree with you about the top cowl and the aesthetics. I've considered it and it may not be completely out of the equation for later on. The certification and cost of the kit would be substantially higher. I'll keep looking for ways to improve it and keep the cost under control, hard to do in aviation.

Thanks again,

David