Vintage Mooney Cowling Mod

[Sabremech]

DaV8or,

Right now it's only part of the upper cowl at a factory seam. The lower cowl I don't quite know how much will be changed. I have looked at the LoPresti a bit and do like what they've done, but can't be anywhere near their price or I won't sell any. Staying away from gear doors and cowl flaps to keep price down at this point.

Clarence,

Thanks for the link. Will definitely check them out.

David

[FloridaMan]

My understanding of what gives the LoPresti cowlings their advantages are that the three holes (two for cooling and one for ram air) are close to the prop and utilize prop pressure. I see 1-2" of MP increase with the ram air open on mine. I would reckon that if the same effect works for cooling then they were able to decrease the surface area of the front of the cowling altogether and still get effective cooling. 

 

Given LoPresti's prices, I'd say there's a nice spot in the market for competition

[DaV8or]

DaV8or,

Right now it's only part of the upper cowl at a factory seam. The lower cowl I don't quite know how much will be changed. I have looked at the LoPresti a bit and do like what they've done, but can't be anywhere near their price or I won't sell any. Staying away from gear doors and cowl flaps to keep price down at this point.

Clarence,

Thanks for the link. Will definitely check them out.

David

 

It sounds like you're doing much what SWTA did with their "201 Style" cowl. A whole new top cowl, baffles, and modified front portion of the existing lower cowl. Their cowl required the 201 spinner also and relocation of the oil cooler. It does not have a plenum. The SWTA cowl is what I have on my plane and I do like it, but does not give me the speed of a real 201 cowl.

 

Might it not be cheaper and easier to just get an STC for the real 201 cowling conversion? Besides looking better and cooling better, people always want more speed. The only thing faster than the stock 201 cowl to date is the Lo Presti.

[Sabremech]

Hi Dave,

I'm doing something similar to what SWTA did with the exception of not doing a new top cowl. If it works as I plan, I'll be changing the front say 6 inches of the upper cowl and a good portion of the lower front. I currently don't plan to relocate the oil cooler as that leads to other issues and raises the cost substantially.

I don't think it will be cheaper to STC the 201 cowling, although it might be easier. The 201 cowl has delamination issues and finding them can be hard and expensive. It also doesn't have the round inlets that I'd like on mine. Another thing I want to keep are the side access panels. I think those are great to have and make it quick and easy to check the engine for issues easily.

There's certainly been some head scratching already and there will be more.

Thanks,

David

[merrja]

Looksgreat!  Please keep us in the loop as I'd love to buy one.

[63C]

Looksgreat!  Please keep us in the loop as I'd love to buy one.

Ditto

[HRM]

Not to change the subject (much), but is there a tutorial or a website that explains how one obtains an STC?

 

Can you get an STC for anything? Like an in panel piece of avionics?

[Sabremech]

On faa.gov look at AC 21-40A for information to obtain an STC.

David

[HRM]

On faa.gov look at AC 21-40A for information to obtain an STC.

David

 

Thanks!

[Sabremech]

The baffling is turning into a time consuming process. The drawings from James Aircraft are pretty good, but I'm changing them just a little as there are some things that Mooney did better that I'd like to incorporate those good things. I make each baffle piece and then trace it again on a piece of paper before bending them. I have to have a drawing for each part, to include the plenum.

I'm still thinking about the carb air box and what to do in regards to that. I really don't want to make a new box as it will drive the cost up, but I may have to in order to get the look I'd like to have.

Here's a few photos of the baffling and plenum installation process.

David

[Hank]

I just did lots of work on my carb heat box. It's all crammed in together down there, a real joy to access.

Good luck, we're all cheering you on with great excitement! A C without a noticeable, squared off chin would be a sight to behold!!

[Gmooney]

Is the mod your making a STC mod for C models or something your working on for the STC mod from the FAA?  I have a 1970 C with the typical problems of the rear cylinders heating during the initial climb.  I do all the typical things to cool the engine in the climb (increase airspeed to over 120 as soon as possible and step climb to altitude), the mechanic has swap the plugs/probes and checked the engine numerous times.  The overheating is not real bad.  Typically in the low 400's and mostly the #4 showing up as the problem.  The engine is fairly new with less than 200 hours and pretty much firewall forward is new including the doghouse seals. 

 

The aircraft has the lower intake cover (Lasar mod) and 3 bladed prop.  I seen some people have had success with the cooling issues but typically only after converting to the 201 style front end completely and strangely some people don't seem to have issue with cooling with just the stock equipment.   

 

So your Mod looks interesting.  Do you need to replace the entire front cowling or this just a mod to the plenum box. 

[Sabremech]

The STC will replace the baffling and add a plenum if there isn't an original doghouse installed. The top cowl will see about 6 inches of it changed by removing the forward section at the factory seam and riveting the new piece in place.

The lower cowl will be modified but hasn't been determined as to how much yet. It looks like I will also have to replace the carb air box with a new style yet to be determined. I'm doing the C & G models right now, E & F to follow. The early C's may present a challenge as the cowling is different than the 65 and up cowlings I believe.

David

[Guest]

David,

Have you looked at the FAB360 air box setup on Vans Aircraft site? A very simple design, efficient at making MAP and cheap to buy.

Clarence

[Sabremech]

Hi Clarence,

I actually have one of those going together on my homebuilt. It's pretty decent except for the carb heat. I think I'll take it and check the fit on my Mooney. Thank you for the idea! This is exactly the reason I'm posting this here! Great ideas from the Mooney community.

David

[Wesley brown]

Please include a m20A model for this application as well. This would be a great addition to my plane.

[Sabremech]

Hi Wesley,

I'm planning on it after getting the C, E, F & G models covered if there's enough demand for it.

Thanks,

David

[Wakeup]

How much difference is there in an A and C Cowling? I have a B and would think a C would be the same. I am following because I would be interested as well for my B. Thanks Troy

[Sabremech]

Hi Troy,

I think, and someone correct me if I'm wrong, that the cowlings are different on pre 65 models than what I have on my 66C. I'll need to get one of those cowlings at some point to make a mod for it.

Thanks,

David

[orionflt]

Dave,

yes the cowlings differ in but the A, B and early C cowls are basically the same. I have a spare lower cowl for my C if you would like to use that when you start looking at including the earlier models, but I think if you just modify the way you mount your new cowl it should fit right on. I would be more then happy to get together with you so you can look at the differences, I fly out to Oshkosh every year so I'm sure we could get together. I may also be able to direct you to where you can get the cowlings made if you decide to do a production run.

 

Brian

[mike_elliott]

The baffling is turning into a time consuming process. The drawings from James Aircraft are pretty good, but I'm changing them just a little as there are some things that Mooney did better that I'd like to incorporate those good things. I make each baffle piece and then trace it again on a piece of paper before bending them. I have to have a drawing for each part, to include the plenum.

I'm still thinking about the carb air box and what to do in regards to that. I really don't want to make a new box as it will drive the cost up, but I may have to in order to get the look I'd like to have.

Here's a few photos of the baffling and plenum installation process.

David

David, to fit your templates, might I suggest using a clear plastic as a template vs. paper? You can see thru for an exact fit.  Here is what I did installing Bruce's Spacial interior to the side panel where the Emergency gear extension was to make it fit.

[Sabremech]

Hi Brian,

Thanks for the offer of help. Every little bit helps towards keeping the cost minimal.

Hi Mike,

I didn't have my clear plastic with me the day I took the last picture and wanted to get one more piece done. You're absolutely correct about it working the best and accurately.

Thanks,

David

[Sabremech]

Decided to take a break from the plenum and baffling to start on the cowling mod itself. Here's a photo of the location for the round air inlets and where they meet up with the plenum.

David

[jamesm]

Hi David,

Looks great.

[Browncbr1]

Man, I hope this thing ends up affordable and doesn't need that 201 spinner! Looks cool!