Sabremech Posted February 19, 2015 Report Posted February 19, 2015 I thought I would start a separate thread to document the STC process for my Mooney cowling mod. I welcome questions as I show and detail the project. My intent is to update the look of the older Mooney cowlings, namely the C,E,F, & G models. Certainly performance gains would be nice and I hope to report any increases once I'm flight testing the prototype cowling on my 66 C. My cowling will incorporate round air inlets for the cylinder cooling air and carburetor air on the carbureted engines. I will be keeping the plenum system as I feel it's the most efficient system for cooling the cylinders. It will also include new baffling. Some of you may recognize the parts I'm using as coming from James Aircraft. They are fantastic to work with and have supported me with parts I need for my STC. This project is being done through my company called GDS Aero. I merged my other company (Vintage Airworks) into GDS at the end of 2104. No sense having 2 FAA quality systems to manage and 2 separate audits each year. On with the pictures: Here's a couple of pictures of the plenum and new baffling being made. 4 Quote
Mooneymite Posted February 19, 2015 Report Posted February 19, 2015 Is this to replace the doghouse found on some models? Quote
Openwheeler3 Posted February 19, 2015 Report Posted February 19, 2015 That looks great! Probably much more effective and efficient at cooling, too! Quote
Sabremech Posted February 19, 2015 Author Report Posted February 19, 2015 This will replace the doghouse baffling found on Vintage Mooneys. It will come with the STC kit. David Quote
Guest Posted February 19, 2015 Report Posted February 19, 2015 David, Are you going to make a new nose bowl to adapt to your air plenum? Clarence Quote
Sabremech Posted February 20, 2015 Author Report Posted February 20, 2015 Hi Clarence, I will be making a new nose section that will rivet in to a factory seam on the upper cowl and yet to be determined on the lower cowl. I'm primarily working on the plenum and baffling right now. The cowlings are in my shop where I can study the changes I want to make. David Quote
Hank Posted February 20, 2015 Report Posted February 20, 2015 This will replace the doghouse baffling found on Vintage Mooneys. It will come with the STC kit. David Hurray!! I've repaired my doghouse the last three annuals. I'd love to get rid of it! Quote
carusoam Posted February 20, 2015 Report Posted February 20, 2015 There looks like three strong advantages could be available for the C... 1) Improved cooling... The dog house in the 65 needed some help. 2) Improved exterior aerodynamics... In 65 the cowl was a big square block 3) Improved image... Something like the O or Acclaim would interesting...? Interesting project progress David. Best regards, -a- Quote
ryoder Posted February 20, 2015 Report Posted February 20, 2015 What is the target retail price and number of hours to install? Quote
Sabremech Posted February 20, 2015 Author Report Posted February 20, 2015 I'll take orders when I have the STC paperwork in my hands! Target price and hours to install will be determined closer to having my airplane done as the prototype. David 1 Quote
ryoder Posted February 20, 2015 Report Posted February 20, 2015 But you need to have a business plan right? Ten thousand? Five thousand? Sell one thousand units per year, recoup fixed costs by two years, make 1k per unit sold in marginal profit by year three, average an internal rate of return of X... Etc. Good luck to you. I don't have the balls for entrepreneurship. Quote
jamesm Posted February 20, 2015 Report Posted February 20, 2015 Hi David, Are you reducing the inlet area/size on pilot side of the dog house baffling ? I haing trouble keeping the cylinder temperature on cylinders #2  cool on take off on occassion I have had them above 450d F on take off during climb out. It seems that the inlet on the Pilot side (Cyl #2 & #4) has a larger area when compare to inlet area on right side (Cyl #1 ) . In my case I suppect that there is turbulent flow in the the dog houes baffling since area is so wide open. I hope this finially that thus resolves cylinder head temperatures plaguing several of us out there. Thanks for taking this project on. It is something that I am interested in. James '67M20C Quote
Steve65E-NC Posted February 20, 2015 Report Posted February 20, 2015 Why not move the oil cooler back and replace it with a redundent landing light and/or taxi light as part of the STC. Build the mount for the oil cooler right into your plenum. Maybe change both lights to 36 style LED since no STC's for 42s seem to be coming. I know project migration / stay focused. But. Quote
mike20papa Posted February 20, 2015 Report Posted February 20, 2015 Another problem common on the 180hp models is the poorly designed carb induction box & boot. It transmits way to much engine vibration into the lower cowling section. Rarely do you see a 180hp Mooney without patch work around the numerous openings - (light, carb opng, oil cooler) the vibration also eats up carb heat boxes, and cowling flaps, not to mention the rubber boot. Some airplanes, the boot is attached to the carb heat box with a doubled up hose clamp and the lower clamp has actually worn a hole/groove into the lower cowling. Best of luck. The James do fantastic work. So, have you gone thru the STC process, before? I don't think the overall shape of the cowling is going to be easily improved without some kind of prop extension and that will drive the FAA guys into a state of hyper anxiety. Quote
Sabremech Posted February 20, 2015 Author Report Posted February 20, 2015 Time to answer a couple of questions posed. Ryoder: business plan, mod my airplane by completing STC. Price reasonably to sell a good quantity. Recover the cost of STC at some point, hopefully in the first year. Goal is to break even and have my airplane the way I want it. Jamesm, the air inlets will be the same size for the cylinder cooling on both sides. Steve65E-NC, oil cooler stays where it is. Moving it will cascade to many other parts being moved for little gained in relation to cost. Mike20papa, I have done the STC process and hold FAA/PMA. I think the cowling can be improved sufficiently enough without a prop extension. It is going to require a 201 style spinner. David Quote
Sabremech Posted February 20, 2015 Author Report Posted February 20, 2015 Hi Daver328, I won't make any claims or promises at this point. I'll have some real numbers when I start flying with the mod early this Summer. Price can't be set until I know what it costs me per kit in parts cost, then I can set a price. I'm aiming for as economical as I can due to the value of our airplanes. David 4 Quote
sreid Posted February 20, 2015 Report Posted February 20, 2015 I don't believe the "doghouse" baffling was used on any F models; I know my 67 F does not have a doghouse. Will your mod adapt to aircraft without the doghouse? Quote
rbridges Posted February 20, 2015 Report Posted February 20, 2015 David, glad to see the progress you're making. I've followed your past threads with a lot of interest. 1 Quote
Sabremech Posted February 20, 2015 Author Report Posted February 20, 2015 Sreid, Yes, the E & F mod will include the plenum and new baffling. Rbridges, Thank you. David 1 Quote
MB65E Posted February 21, 2015 Report Posted February 21, 2015 Hi David!! Any thoughts about using the stock (non 201) spinner? I have thought about getting a 337 done to have the top of the doghouse brought fowdard to enclose the area behind the spinner. This would clean up the rough air, and you could even keep most of the cowl, encorporate the lower cowl closure if you wanted etc. Similar to a late 70's 182 or somthing like that. Nice work, stay warm! -Matt Quote
Sabremech Posted February 21, 2015 Author Report Posted February 21, 2015 Hi Matt, I haven't really thought of that. I have the 201 spinner on mine already and like it. I do need to find a source to supply the spinner so that could dictate a change. Trying to stay warm, but hard to do this year!! Take Care, David 1 Quote
Browncbr1 Posted February 21, 2015 Report Posted February 21, 2015 Hi Matt, I haven't really thought of that. I have the 201 spinner on mine already and like it. I do need to find a source to supply the spinner so that could dictate a change. Trying to stay warm, but hard to do this year!! Take Care, David I'm in the same situation. I was nearly ready to buy the ari cowl for my 67F, but realized I would have to get the 201 spinner and backplate. The extra cost of those put the whole idea out of my head. Hope you can make this work with non-201 spinners! 1 Quote
DaV8or Posted February 21, 2015 Report Posted February 21, 2015 Is this a completely new cowl top and lower, or just the top half and baffles? If you're doing the lower, are you going to do a new Ram Air system like Lo Presti did? What about gear doors and cowl flaps? How much have you looked at Lo Presti has already done? Looks good so far and keep up the good work! Quote
Guest Posted February 21, 2015 Report Posted February 21, 2015 Hi Matt, I haven't really thought of that. I have the 201 spinner on mine already and like it. I do need to find a source to supply the spinner so that could dictate a change. Trying to stay warm, but hard to do this year!! Take Care, David Check with www.tcbcomposites.com They may be able to help with a spinner ans bulkhead. Clarence Quote
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