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300hp Missile Conversion of M20J - Pros and Cons


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MS was so new at the time...

This thread was started on my second day as a member...

I found MS while looking to learn about Missiles...

Roughly 31,657 posts ago...

It took several months to gather just a few responses...

I visited with one MSer selling his Missile, as he was traveling past NJ...

About six months later... I had finished my IR and bought my M20R...

Great memories...

Go MS!

Best regards,

-a-

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On 9/25/2020 at 10:32 AM, Missile=Awesome said:

R. A Missile plus even more to love. How sweet it is...Except the deeper pocket hit on entry into the show. 

Through the years I’ve followed prices for Missiles and 20J’s in trade-a-plane. They don’t come up as often in recent years, but the price differential between Missiles & 20J’s has decreased. Perhaps because people aren’t as familiar with the Rocket product? On the rare occasion that they come up, Missiles aren’t going for too much more than similar vintage stock J’s.

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14 minutes ago, Hillndale said:

Through the years I’ve followed prices for Missiles and 20J’s in trade-a-plane. They don’t come up as often in recent years, but the price differential between Missiles & 20J’s has decreased. Perhaps because people aren’t as familiar with the Rocket product? On the rare occasion that they come up, Missiles aren’t going for too much more than similar vintage stock J’s.

I think he was referencing Anthony's M20-R, with the 310hp upgrade. It's a good comparison with the Missile, with more interior room, slightly higher fuel burn and higher pricing structure. Missiles are definitely a step up from the J, there are just not many of them . . . . Looking for one is how Anthony ended up in an R. Be careful!

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On 6/14/2009 at 6:01 AM, carusoam said:

I have sold my '65 M20C.  While searching for its replacement M20J,  I have come across a few Rocket Engineering conversions.  I am interested in your knowlege and opinions of the upgrade, The upside is clearly advertised, what are the "hidden" downsides.

 

Background according to Rocket Engineering:  "The 300 hp, normally aspirated, Continental IO-550-A engine provides out of this world performance for the Rocket Engineering 300 Missile conversion."  "Hartzell 3-bladed, full feathering propeller especially designed for the Missile conversion with low noise and high performance."

 

 

Thanks for your insight.

 

My “straight” M20J is a ‘78 with 64 gallon tanks, Aspen driven K150 autopilot, G430W. My Missile 20J is a ‘93 Rocket STC’ed in ‘95 with 92 gallon tanks, 2 Aspens driving a KFC200 autopilot, G530 & Avidyne 440 (recently replacing a G430W...very happy). Both planes have a mid-continent Lifesaver installed and no vacuum instruments, good engine monitors (including fuel flow) and Gami-jectors (I routinely cruise at LOP in both planes).

Both planes fly very similarly once in the air with the exception that the Missile climbs better at all altitudes and gets off the runway faster. The straight 20J does not have air brakes (& doesn’t need them if flown appropriately)...the Missile has them and needs them. Both airframes are clean but the additional mass/momentum for the Missile translates into a little more attention when descending or flying into shorter fields.

Both aircraft have similar useful loads but the Missile performs dramatically better when at max wt. 

The Missile is smoother despite the additional power. I don’t know how much of this is 3 vs 2 blade prop and how much is 6 vs 4 cyl engine. Both aircraft are prop balanced to similar tolerance numbers. Both planes are getting new 1/4” windshields this winter while COVID and weather has reduced flying. I’ll be curious to see if this brings noise levels closer.

The J is more “efficient” in a miles per gallon sense in no wind conditions but that advantage shifts to the Missile with significant headwinds. The Missile will still be moving along at 130 kts with a 50 kt headwind (72% of still air speed) while the J drops to 100 kts (67% of still air speed). I’ve set my J down and waited for better winds, but haven’t with the Missile. For a fair comparison I’d have to fly both planes at the same airspeed and altitude and fuel/passenger load, adjust to LOP and see what the numbers are...something I haven’t done yet. But in the real world it’s not likely that many pilots would resist the temptation to go faster, making straight J efficiency in the Missile “theoretical”. 

I’ve had my right tank leak on the Missile (patched without requiring a total strip and reseal). I’ve never had a problem with my 15 year older J. After the leak was repaired my research and discussion suggests that landing with heavier loads (lots of fuel in extended tanks) and older, stiffer doughnuts can increase the risk of leaks. I don’t keep the tanks full all the time now (but it used to give great assurance knowing I could fly 6.8 hrs @ 175-180 kts before running dry!).

The Missile requires more attention to head temps on climb out. I am very conservative on this and try to keep the temps south of 380 (never allow >400). But this is more of an issue on hot summer days and not an issue at all in other seasons. Even cruise climbing at 120 kts (for cooling) the Missile climbs at sea level through ~6000ft @ >500 fpm with 2 people and full fuel. There are no cowl flaps on the Missile but for the additional workload of managing the cowl flap settings, the J offers a little more control of cooling than just “go faster to stay cooler”. The J is a little easier to keep cool in hot weather.  I think the cyl head “redline” is 450 (I’d have to go look at the gauge to be sure), but I wouldn’t feel comfortable with temps that high even briefly for take off.

Maintenance has been similar. The airframe firewall back practically is the same. The Missile landing gear has been reinforced but the doughnuts are the same. The cont IO550A in the Missile has 2 more cylinders to care for and the prop has an extra blade...roughly speaking this might work out to an additional 50% expense firewall forward. Both the J & Missile are tightly cowled...the Missile slightly more so. I developed some heat damage to the paint on the cowl over the #6 (left forward) cylinder many years ago. When the cowl was repaired and heat shielding in the area was replaced, it chafed that cylinder head cover and had to be reworked. Interestingly, my brother had the same issue with his Ovation.

The exhaust system on the Missile is designed and built by Rocket. I’ve had the exhaust system rebuilt once by them ~15 years ago and this year had the muffler repaired by another shop closer to home to address a deformed spark arrester cone. The exhaust system in the J has required no significant work.
 

The engine mount for the Missile’s IO550A is well engineered and sturdy, but requires attention where the support tubes are near the exhaust as the heat is hard on the paint and if neglected, corrosion could become a significant problem. Through the years, I’ve stripped and painted the lower parts of the support twice (while in place). High heat paint holds up better, & careful attention to inspecting and maintaining the heat shielding pays off.

Hot starts are more problematic with the Missile. I’m installing a Surefly electronic ignition this annual. One of the claimed improvements with EI is hot starting so we’ll see. Surefly doesn’t have a unit that works with the dual mag single drive system in the J’s io360.

Overall they’re both wonderful airplanes. Mooney support has been good through the years despite they’re ownership ups and downs. Rocket engineering support has been consistently good as well...and I’ve only rarely needed it!

Ive had both from coast to coast and into south eastern Canada but I do seem to fly the Missile a little more, particularly on longer trips.

My general thoughts after flying my 2 Mooney’s for 25 years...

Don’t be afraid to buy a Missile if you come across one in good shape for a fair price, you won’t regret it. My wife and I flew back from Barr Harbor to Louisville a few years ago skirting well north along the Great Lakes to stay out of a hurricane blowing up into Virginia and never had to worry about running out of time in the air despite the weather related extreme course deviations.
 

If a J comes up that is in good shape at a fair price, you won’t regret that either. Extended tanks can make a J’s legs as long as a Missile. It might not climb as well with the additional weight, and won’t be quite as fast...it’s performance is still very respectable. And from what I’ve seen so far, the J’s seem a little better at holding their market value. When avgas goes back up this may be more true.

Hope this is helpful.

 

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On 6/14/2009 at 6:01 AM, carusoam said:

I have sold my '65 M20C.  While searching for its replacement M20J,  I have come across a few Rocket Engineering conversions.  I am interested in your knowlege and opinions of the upgrade, The upside is clearly advertised, what are the "hidden" downsides.

 

Background according to Rocket Engineering:  "The 300 hp, normally aspirated, Continental IO-550-A engine provides out of this world performance for the Rocket Engineering 300 Missile conversion."  "Hartzell 3-bladed, full feathering propeller especially designed for the Missile conversion with low noise and high performance."

 

 

Thanks for your insight.

 

My “straight” M20J is a ‘78 with 64 gallon tanks, Aspen driven K150 autopilot, G430W. My Missile 20J is a ‘93 Rocket STC’ed in ‘95 with 92 gallon tanks, 2 Aspens driving a KFC200 autopilot, G530 & Avidyne 440 (recently replacing a G430W...very happy). Both planes have a mid-continent Lifesaver installed and no vacuum instruments, good engine monitors (including fuel flow) and Gami-jectors (I routinely cruise at LOP in both planes).

Both planes fly very similarly once in the air with the exception that the Missile climbs better at all altitudes and gets off the runway faster. The straight 20J does not have air brakes (& doesn’t need them if flown appropriately)...the Missile has them and needs them. Both airframes are clean but the additional mass/momentum for the Missile translates into a little more attention when descending or flying into shorter fields.

Both aircraft have similar useful loads but the Missile performs dramatically better when at max wt. 

The Missile is smoother despite the additional power. I don’t know how much of this is 3 vs 2 blade prop and how much is 6 vs 4 cyl engine. Both aircraft are prop balanced to similar tolerance numbers. Both planes are getting new 1/4” windshields this winter while COVID and weather has reduced flying. I’ll be curious to see if this brings noise levels closer.

The J is more “efficient” in a miles per gallon sense in no wind conditions but that advantage shifts to the Missile with significant headwinds. The Missile will still be moving along at 130 kts with a 50 kt headwind (72% of still air speed) while the J drops to 100 kts (67% of still air speed). I’ve set my J down and waited for better winds, but haven’t with the Missile. For a fair comparison I’d have to fly both planes at the same airspeed and altitude and fuel/passenger load, adjust to LOP and see what the numbers are...something I haven’t done yet. But in the real world it’s not likely that many pilots would resist the temptation to go faster, making straight J efficiency in the Missile “theoretical”. 

I’ve had my right tank leak on the Missile (patched without requiring a total strip and reseal). I’ve never had a problem with my 15 year older J. After the leak was repaired my research and discussion suggests that landing with heavier loads (lots of fuel in extended tanks) and older, stiffer doughnuts can increase the risk of leaks. I don’t keep the tanks full all the time now (but it used to give great assurance knowing I could fly 6.8 hrs @ 175-180 kts before running dry!).

The Missile requires more attention to head temps on climb out. I am very conservative on this and try to keep the temps south of 380 (never allow >400). But this is more of an issue on hot summer days and not an issue at all in other seasons. Even cruise climbing at 120 kts (for cooling) the Missile climbs at sea level through ~6000ft @ >500 fpm with 2 people and full fuel. There are no cowl flaps on the Missile but for the additional workload of managing the cowl flap settings, the J offers a little more control of cooling than just “go faster to stay cooler”. The J is a little easier to keep cool in hot weather.  I think the cyl head “redline” is 450 (I’d have to go look at the gauge to be sure), but I wouldn’t feel comfortable with temps that high even briefly for take off.

Maintenance has been similar. The airframe firewall back practically is the same. The Missile landing gear has been reinforced but the doughnuts are the same. The cont IO550A in the Missile has 2 more cylinders to care for and the prop has an extra blade...roughly speaking this might work out to an additional 50% expense firewall forward. Both the J & Missile are tightly cowled...the Missile slightly more so. I developed some heat damage to the paint on the cowl over the #6 (left forward) cylinder many years ago. When the cowl was repaired and heat shielding in the area was replaced, it chafed that cylinder head cover and had to be reworked. Interestingly, my brother had the same issue with his Ovation.

The exhaust system on the Missile is designed and built by Rocket. I’ve had the exhaust system rebuilt once by them ~15 years ago and this year had the muffler repaired by another shop closer to home to address a deformed spark arrester cone. The exhaust system in the J has required no significant work.
 

The engine mount for the Missile’s IO550A is well engineered and sturdy, but requires attention where the support tubes are near the exhaust as the heat is hard on the paint and if neglected, corrosion could become a significant problem. Through the years, I’ve stripped and painted the lower parts of the support twice (while in place). High heat paint holds up better, & careful attention to inspecting and maintaining the heat shielding pays off.

Hot starts are more problematic with the Missile. I’m installing a Surefly electronic ignition this annual. One of the claimed improvements with EI is hot starting so we’ll see. Surefly doesn’t have a unit that works with the dual mag single drive system in the J’s io360.

Overall they’re both wonderful airplanes. Mooney support has been good through the years despite they’re ownership ups and downs. Rocket engineering support has been consistently good as well...and I’ve only rarely needed it!

Ive had both from coast to coast and into south eastern Canada but I do seem to fly the Missile a little more, particularly on longer trips.

My general thoughts after flying my 2 Mooney’s for 25 years...

Don’t be afraid to buy a Missile if you come across one in good shape for a fair price, you won’t regret it. My wife and I flew back from Barr Harbor to Louisville a few years ago skirting well north along the Great Lakes to stay out of a hurricane blowing up into Virginia and never had to worry about running out of time in the air despite the weather related extreme course deviations.
 

If a J comes up that is in good shape at a fair price, you won’t regret that either. Extended tanks can make a J’s legs as long as a Missile. It might not climb as well with the additional weight, and won’t be quite as fast...it’s performance is still very respectable. And from what I’ve seen so far, the J’s seem a little better at holding their market value. When avgas goes back up this may be more true.

Hope this is helpful.

 

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Hilln,

You’ve done it! :)

That was the answer I needed and was looking for when I came across MooneySpace for my first time...

It took a while for MS to gain enough traction...  there was a new post or two every other day... the chance of getting good Rocket Engineering feedback back then was slim...

I knew one person who was selling his Missile... I was looking for feed back from other Missile owners...

Being a fan of putting large motors in ordinary cars... the Missile was very attractive for much of the same reason...

Since the day I wrote that post.... I have written about 32.7k more...

Wish you were here then! 
 

I ended up going with the M20R a few months later.  I really am a fan of the IO550...

Thanks again for the reply... that will be very helpful for somebody moving from an M20C to the next NA Mooney... like I did...

Best regards,

-a-

 

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After your pointing out just how long ago you posted your original lead to this string had been, I thought it would be fun to address the original question directly.

There aren’t as many Missiles coming up anymore to consider...but there are a few, hopefully this will help a 20C owner take one on.

I’d be curious to know how many Missiles and Rockets are still healthy in the fleet and how many hours per year they’re being flown.

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Scott is probably our most recent Missile owner... @Missile=Awesome

He happened across one that was begging him to get it out of wherever it was being kept hostage.... :) 

If you want to find out how many MSers have a Missile... start a new thread... see how many respond...

It is also possible to search through the member files... if they wrote Missile under what they fly, you can probably get a good feel for how many are around here...

@Seth has had his Missile for a few years... and may know some details about other Missiles around here...

Best regards,

-a-

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I liked Hill’s comparison very much as well.  I have 98 gallon (total) 17 a side Monroy extended tanks and NO speed brakes.  I haven’t felt that the Missile was much different from my M20E in decent going downhill.  I like having the S-Tec auto pilot and dial in 500fpm and slowly pull MP a couple inches every couple of minutes in decent.  No issues keeping on or slightly below 180 knots indicated in decent.  (Smooth air).  I would agree that options are nice so speed brakes would be a benefit, but frankly I don’t feel I need them and I certainly don’t miss not having them on our Missile.  I would enjoy seeing interior and exterior photos of your bird Hill.  Scott

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Scott, I agree that the Missile could get by without air brakes (your recount proves the point) and I typically hold off deploying them most of the time. But I’ve been in situations where ATC has kept me high until the last minute, then requested I cross an intersection at an altitude that would have been tough to comply with if not for speed brakes. They do give options that make operations easier on the engine & airframe and also allow the pilot to take advantage of the Missile’s speed/altitude into later phases of a flight.

An interesting digression is that I’ve always assumed all Missiles came with speed brakes and extended tanks (& other standard goodies) in addition to the engine/prop/gear upgrade that is at the heart of the STC. I’m finding I’ve been mistaken! Until recent years I’ve not had the time to investigate the question.

I’ll see if I can pull some photos up & post for you.

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Here’s a couple of shots of my Mooney’s in their hangar. The one on top is my straight ‘78 20J, on bottom is my ‘95 Missile (positioning gives a strong clue to what I fly most!).  I’ll rummage around my files for some inside photos of the Missile.
Dale

B97E140B-FEB4-415A-8D50-CB682F8EF901.jpeg

FB40E7A9-52E8-4E8B-814E-E78635858E06.jpeg

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An interior shot of the Missile taken when I picked up my mom’s sister in Biloxi, and a shot of part of the panel...

Sorry, not the greatest pic’s to show the plane (I’m usually taking photos for some other reason)...but gives you an idea. Oh and I noticed on the panel shots, the Aspens are showing TAS 183 kt at 13000...illustrating that the numbers in our threads are if anything, conservative.

Ive got better interior panel shots, but these were readily available on my phone.

8266558F-C336-4B77-8BE4-DBEFF55A1A31.jpeg

992BCBAF-B039-49F7-9EA0-682B4E0A4147.jpeg

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40 minutes ago, Hillndale said:

Here’s a couple of shots of my Mooney’s in their hangar. The one on top is my straight ‘78 20J, on bottom is my ‘95 Missile (positioning gives a strong clue to what I fly most!).  I’ll rummage around my files for some inside photos of the Missile.
Dale

 

FB40E7A9-52E8-4E8B-814E-E78635858E06.jpeg

Ok - you win the mooniac of the month award.  Hands down!

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13 minutes ago, carusoam said:

Caution: G force sensitive instruments, installed...

Here’s my Aspen, and my other Aspen....

Here’s my Mooney, and my other Mooney...

Holey cow, that’s a headwind!

:)

-a-

8732D415-1064-4A1C-A05B-71E066F1C08C.jpeg

185 down to 159 is a healthy headwind, but hardly 'Holy Cow!' status . . . .

One evening going hime to WV around some low level icing (emergency PIREPS on the lowest MEA in WV get my attention], wd were motoring along at 10,000msl between KGSP and KTYS, clearing terrain and minimizing dodging belkw-freezing cloudtops, I was indicating 140 mph [TAS = 140 + 28 = 168 mph ~ 146 KTAS, while my faithful 430W shiwed groundspeed of 68 knots. No photo, it was too depressing . . . . .

Mynwife said she was glad we weren't in a Cessna, we'd never get home. I was wishing I had upgraded to a Missile! 

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