LoPresti Cowl Kit...do you want one?

[PTK]

In my humble opinion and based on my very limited experience I think on a non J I could see going to the LoPresti cowl, MAYBE if it was 2-3K max and then maybe ??????? But absolutely positively NOT for a J!   Not for 13 -15K $ !!! The J cowl is refined to maximum aerodynamics.  I don't see spending this kind of money for a questionable 1-2 mph if that.

I would rather remove the RAM (SERVICE INSTRUCTION M20-93) hardware, and take the  J cowl to an autobody shop.  You can have a beautiful cowl perfect and painted for under 1 grand!!  At least this is what I was quoted.  I plan to do this at next annual.  For more of an cosmetic improvement remove the landing light also.  I plan to place landing/taxi lights in the wings. Total cost parts and labor ~$2600. (2 wing mounted light fixtures, labor to install them, remove RAM and refinish and paint cowl). 

 

[testwest]

For those looking for a used M20J cowl and airbox etc (basically everything removed from a J for the Lopresti cowl, including the nose gear doors) I have the lot on sale at Barnstormer's, it should come up under the "Single Engine - Mooney" subcategory. Thanks!

[crxcte]

Send me a link of the ad.

 

Chris

[testwest]

Hi Chris...I am sorry, but the cowl has been sold. I will have another ad on Barnstormer's for the exhaust system soon. In the meantime, take a look at this! Finally flew last week after being down for a couple years!

We did the Powerflow Gen 1 with Quietpipe and the Lopresti at the same time, so we won't be able to determine discrete perf gains attributable to either mod, but I can safely say in the aggregate we have gained at least 7 knots in TAS at 10000 ft, possibly more. The results are preliminary right now, we'll get better data later on, and we'll especially get more like-condition data to our baseline data on hand.. We are in Troutdale OR right now for tank seal work.

Engine cooling and especially oil cooling is WAY better than before. Standard day full power climbs are possible with the cowl flaps closed with OTs in the 210F range. Before, this condition would result in a quick excursion to oil temp redline.

Others have reported that the Powerflow is loud, or does not provide enough cabin heat. For us, the noise is the same with the Quietpipe and the heat seems just as good as before (which is terrific).

Ram air is outstanding, we see a solid 1 inch gain at 10000', about 140 KIAS or so...

All the gray/green primer parts in the photo hint at other drag reduction measures on this 1977 M20J. We went with factory wing tips with the hidden counterweights and the smooth belly....among other things.

More later, we should be done with tank sealing around April 10.

[hansel]

Just a thought... maybe your nose-low attitude is contributing to the gain in TAS?

[testwest]

Hehehehe, no, I don't think so!! That photo was cropped from a fairly wide shot, and the data (during a different phase of flight, not as wingman for photos!!) were taken as good as I know how to do in terms of aircraft trim at level flight.

Again, our data are preliminary, and there will be more later.

The trip from Mojave to Redding CA (not Palmdale, the site has a mistake on the destination) was gratifying, yes there was some tailwind but....http://flightaware.com/live/flight/N201JX/history/20100305/2010Z/KPMD/KMHV/tracklog

Another picture for y'all, this shows the smooth bellly, Lopresti nose gear doors, Lone Star Aero (nee Modworks) composite main doors with LASAR rotated calipers, and the Powerflow Quietpipe. And yes, the tanks are leaking some, and yes, she needs paint bad.

[testwest]

Good eye on the antennas! We do not have a single external antenna forward of the baggage compartment.

When we removed the nav antenna from the tail, the vertical fin skin underneath had been cut very raggedly, this was from the factory in 1977. It was cheaper just to replace the skin (and lighter, too).

Same thing for the upper fuselage skin that is now in green primer, after removing the old vent system that was riveted to the upper fuselage (with button head rivets), the tilt-up vent intake and the "7" antenna, and wanting to get at the fixed shoulder harness installation that "must have" been done at the factory (even though no one, not even Dennis Bernhard at Lone Star, had ever seen a drawing or heard of this fixed install before, it placed the shoulder harness way too close to the neck), it was easier to replace the upper fuselage skin. Lone Star happened to have an NOS skin in stock, we got it for little more than the raw material cost. 

The wing tip hidden nav antennas work great. The hidden transponder antenna in the belly is not so good. We will probably have to mount it externally aft of the smooth belly skin....

[fantom]

Those wing root fairings are also a very nice touch.

 

 

[KSMooniac]

Norm, that is amazing!  You've done about everything I thought about doing, but I only opted for the modified dorsal fin/root, and hinge covers before paint last year.  I decided not to go with the LoPresti after reading a mixed bag of comments.  I would have liked to delete my pop-up cabin vent too and go with the later model system, but it seemed like a huge amount of work to do so...

Did Lone Star do all of this work for you?  Which smooth belly mod did you choose?  What is your empty weight/useful load after all of these improvements?

I'm still toying around with my own TN-system idea, and if that goes, I think I will make a new cowling system from scratch out of carbon fiber to offset some of the weight-gain of the turbo system.  Losing ~10 lbs with an MT prop and perhaps 5-7 lbs in the cowl would help tremendously.

 

[DaV8or]

Thanks Norman for posting the picture of your undersides. I hear about these mods all the time but it is awsome to actually see them in action. Now I more fully inderstand what they mean by "inner doors" and "one piece belly".

[testwest]

Why thank you to everyone! I'll try to answer a few questions.

The wing root fillets are from Lake Aero Styling and Repair, Mod 111. Their web site shows a half mph speed increase from this mod....but if you have TKS de-ice on the airplane you can't install them. Look cool, but I couldn't quantify any speed gain from the fillets in and of themselves. But they look cool.

BTW LASAR has a Lopresti-cowled 78 J on sale on their site $79.9K.

Replacing the pop-up vent with the later dorsal intake was very expensive. I bought as many parts as I could from salvage and picked up new plastic parts from Mooney. The parts manual is a great resource to show what is needed. I took a lot of pictures at the salvage yard before removing what I needed to document install details. The new upper fuselage skin was a totally lucky break, Lone Star had one that was made for another customer but never picked up. To get another one of those skins would require Mooney to pull their drop-hammer dies for that part out of storage and bang out a new one. Literally.

The new overhead vents are very quiet, much less drag and puts out a lot of air right where you need it.

The smooth belly and the wingtips are all factory new parts from Mooney and/or Lone Star. I did not use any parts from SWTA. Lone Star has a boatload of new-old-stock/surplus parts bought from Mooney when Mooney ceased production of the mid-body models. Parts Manager is Kevin Durkee, great folks there!

The work was done by Antelope Valley General Aviation Services in Mojave, CA. Rob Loughlin is the principal there, he is one of those guys that can figure out an approvable way to do just about anything, and has worked on all kinds of planes you have never heard of, such as the National Test Pilot School's NDN Firecracker...he rebuilt a wing for that plane from scratch after having the factory wing jig shipped from England.

Our empty weight is OK, sort of. I don't have the paperwork with me right now, we still have to remove the old Brittain AP stuff and we have a couple other weight reduction ideas which may or may not work. The smooth belly is actually kind of heavy. A vaccuum-bagged carbon piece would probably be half the weight. I "heard a rumor" that Dugosh had just such a mod. but....

The composite gear doors are interesting, I have heard them called "inner doors" or "middle doors", some Mooneys have 3-piece gear doors, the outer is on the gear leg, the middle is on the wheel, and the inner is hinged to the inside edge of the wheel well opening, and is actuated by yet another marvelous Mooney welded-tube-and-geegaw system. With the rotated caliper/composite door system we have, to fit inner doors would require all-new inner doors along with the geegaws....since the stock inner doors match the older large-bulge middle doors. Yeesh.

Scott, good luck with the TN idea, next time I am in Wichita I'll look you up. What would really be cool would be to take the best ideas from Bill Sandman's M-20 turbos, and Tornado Alley Turbos and work up a new configuration. The TAT TN A36 Bonanzas are wicked fast, but there is a TN airplane out there that takes the Mooney approach to the next level....it's called an Aerostar 601P. Yep, got a 1977 one of those too, $135k last summer at the bottom of the market....but it needed "some work, XX AEMUs" as one would expect. Eastern Mooney Monetary Units = $100, Western MMUs are $1000, an Aerostar Monetary Unit is $10,000. Yowch. 

[67M20F]

Quote: testwest

Mooney Monetary Units = $100, Western MMUs are $1000, an Aerostar Monetary Unit is $10,000. Yowch. 

[KSMooniac]

Norm, thanks for the details!  I came close to buying the Dugosh carbon fiber belly last year before paint, but decided to wait when I learned that the install was much more involved than I had heard previously, and I didn't want to part with more cash in a questionable job market for aircraft folks like me.  I'll likely add it in the next year or two, I expect, and I got some extra paint to match it.  It appears to be weight-neutral over the OEM '77 configuration, so I like that.  Useful load is precious!  I opted to skip the root fairings and wingtips since I favored useful load over improved looks.  I sorta wish I would have went ahead with the pain to convert the overhead vent, though!

Definitely give me a shout whenever you find yourself in Wichita.  I used to work for Boeing, and now Spirit.  I expect you might have a reason to visit the remaining Boeing operations here sometime.  I love Aerostars too, but can't ever imagine keeping one flying!  They are complicated and expensive, but they can boogie. 

[KSMooniac]

Jim, in my mind, it is drag reduction and improved ventilation if the anecdotal stories I hear are correct.  It would also be slightly quieter vs. the clamshell.  It would likely be a slight weight gain.  In my case, I think I would have needed a new headliner plastic piece/plenum (maybe) in addition to the new top skin and the new ventilation plumbing from the rear to bring it forward.  It sounds like Norm got really lucky with the top skin deal, but it still is expensive. 

At the time I bought my plane, getting into a J of any vintage was a budget stretch, but my plane came along at the right time and at a good price relative to what was installed, so I stretched to get it.  I'm on record as not liking some of the '77 features like the throttle quadrant and square-tipped prop, but I just couldn't get into a later model.  I do love my useful load, though, so I'm slowly improving the airframe to get it where I want it to be, while enjoying the installed equipment and general great condition.  Sooner or later I'll upgrade props and install the smooth belly, and make my rear seat a quick folder.    I'll probably continue to live with the clamshell vent.

[KSMooniac]

I have done a little bit of work professionally in support of noise reduction improvements on Boeing engine nacelles, and as part of that work I got learn about sources of environmental noise that folks hear on the ground.  Obviously the engines contribute most of it, but surprisingly the airframe can be "heard", especially in the landing configuration at low power.  Flaps, slats, landing gear, gear doors, etc. all have noise contributions, so generally speaking an aerodynamically "clean" airframe will also be a quieter airframe.

My main goal is drag reduction to get more efficient speed of course, but in the case of that clamshell vent, it literally sits a few inches away from the front-seaters' ears, so noise reduction is a secondary, but very welcome, benefit.  There is a noticeable 1-2 knot loss from open to closed, and I expect there would be a 1-2 knot benefit to remove it entirely.

[testwest]

Jim, you are exactly right. The photos below show the new interior Royalite and vents. Plane Plastics of Alva, OK, provided all of the interior Royalite....during the mods we decided it was time for an all new interior and glass...the glass came from Great Lakes Aero Plastics, they are WAY cheaper than LP and are the subcontractor to Mooney for OEM glass (OK, plexiglas) AFAIK. We still have to install cloth speaker covers over the cabin speaker and Sonalert horns, and paint the Royalite....what's that you say? Never heard of painting Royalite?

New Royalite can be painted and protected very nicely these days with SEM Color Coat plastic paints. SEM is amazing, the paint fuses to the Royalite, it won't flake off at all, and protects the plastic from UV. I see a lot of folks covering over their old Royalite with fabrics and spending more (and making it heavier) than simply replacing and painting it with SEM. All the info on SEM paints is here http://semaerospace.com/as/ the step-by-step approved instructions are here http://semaerospace.com/images/Users/1/aero/pdfs/Refinishing%20Plastic%20Process%20CCPA-102.revised.2.08.pdf and it can be purchased through Plane Plastics. 

BTW, we kept our old overhead ducts and the circular vents that go with them. Can provide pix in three weeks (I am in Australia right now) if anyone needs replacements of the legacy system. They are in "OK" shape, and could be fixed up/restored with SEM Sure-Coat if need be. It is left as an exercise to the reader to find the info on Sure-Coat....

[testwest]

Thanks so much for the kind words!

I think I am still getting inspiration from Dr. Brien Seeley's article published in a summer 1982 issue of Sport Aviation magazine on his highly modified 1966 E model. For determining performance, he always ran the airplane at the same conditions: 8000' altitude (to be perfectly comparable, one should run at constant density altitude, I am sure he took this measure of care but the article did not provide this level of detail), WOT, 2700 RPM, leaned for best power, one person on board, full fuel, ram air open and all air vents closed. I would suggest his configuration become the single standard data condition where we all measure before and after mods cruise at ~75% power.

Dr. Seeley's before speed in this condition was 153 knots for a stock 1966 M20E. After a huge number of mods, including an annular one-off cowling and the world's first Lopresti-designed Mooney 3-door MLG gear system, his after speed was an incredible 186 knots! This is with a box-stock IO-360-A1B6 engine. This speed gain and the economy cruise he could get at near the old speed - 155 knots on 7 gph - was all done in 1980-1982. I have a PDF copy of this article on this amazing transformation, PM me if you want a copy.

I don't think many folks know the huge influence the CAFE Foundation has had on GA airplanes and especially Mooneys. The Mooney three-door MLG design had its genesis on Dr Seeley's M20E. The inertially tuned exhaust system research, flight test and papers published by CAFE led to the design and marketing of Powerflow Exhausts. Lopresti Speed Merchants was borne from the ideas of CAFE and Mississipi State University's research on piston engine cooling drag, that's where the axisymmetric intake nostrils we see on a lot of airplanes came from.

http://cafefoundation.org/v2/main_home.php

http://www.raspet.msstate.edu/index.php

 

[67M20F]

Wow that is impressive, I want a plane that I can fly non stop to the lower 48.

1488km at that, that would be nice, add a turbo to get to the FL's and whooo hoooo, that would be knocken on  a ovation, I would think.

[67M20F]

With the extended tanks to put the fuel at 100gal burning 8gph you could go 2325KM, thats 12.5 hrs sitting in the seat but wow that would be cool.

[Bacachero]

Quote: KSMooniac

Norm, that is amazing!  You've done about everything I thought about doing, but I only opted for the modified dorsal fin/root, and hinge covers before paint last year.  I decided not to go with the LoPresti after reading a mixed bag of comments.  I would have liked to delete my pop-up cabin vent too and go with the later model system, but it seemed like a huge amount of work to do so...

Did Lone Star do all of this work for you?  Which smooth belly mod did you choose?  What is your empty weight/useful load after all of these improvements?

I'm still toying around with my own TN-system idea, and if that goes, I think I will make a new cowling system from scratch out of carbon fiber to offset some of the weight-gain of the turbo system.  Losing ~10 lbs with an MT prop and perhaps 5-7 lbs in the cowl would help tremendously.

 

[KSMooniac]

Hi Bacachero.  Not yet, I'm afraid!  It is still on my wish-list but I have another idea I'm going to try first...smaller scale and hopefully easier to execute.

[fantom]

Just before Mod Works was blown away by Hurricane Charlie, I viewed a really nice carbon fiber cowling they were trying the get FAA approval for. It (they) were flattened when the paint shop came crashing down.

[PTK]

 The consensus is that the J is a great airplane. But yet it's disturbing that some want to mess with it and alter it with cowl, prop, etc etc,  For what and to what end???  What will we gain with these mods? 

Leave th J alone.  It's a great airplane!

 

[fantom]

Quote: allsmiles

Leave the J alone.  It's a great airplane!