carusoam

300hp Missile Conversion of M20J - Pros and Cons

23 posts in this topic

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.

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One really big negative, in my view, is what Rocket told me when I was looking at a few of their conversions in 2005.  I asked how long they would continue supporting these, as they are now discontinued.  Their rep said "oh, 10 years maybe?"  That was 4 years ago.  Keep in mind that there are quite a few Rocket (and Missile) - specific parts in the conversion that only they make, so upkeep in the next decade may become sketchy.  Also, I think they only converted a handful of J's to the Missile, like 20 maybe?  Very limited numbers.


Another consideration, as Jim said, is the extra weight on the nose gear.  Be prepared to replace the doughnuts frequently, and be mindful of the condition of your nose gear.  It is now supporting much more weight than it was designed for.  I've heard pilots who've flown these say that it is sometimes difficult to get enough nose-up trim for landing, too.


Having said all that, I wish Rocket were still doing these.  We just did an overhaul on 5KD, and if this conversion had been available, I betcha we would have done it!  It would have made for a screamer!  But, fact is, it's an orphaned conversion, or at least will be soon.


 

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The only drawbacks I have seen on this conversion are: increased noise level, nose gear damage and shorter range.


The increased noise level can be overcome with good ANR headsets. The gear damage happens upon landing were if comming too fast the plane would porpoise and if comming to slow there is not enough elevator power to keep the nose up. Best way to overcome this is to raise flaps just before touch down or increase tail ballast. The shorter range comes from the increased fuel flow. No sense on having a fast plane if you have to stop for refueling. This can be overcome with the installation of long range tanks.


José


 

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Quote: mooney205kd

 Keep in mind that there are quite a few Rocket (and Missile) - specific parts in the conversion that only they make, so upkeep in the next decade may become sketchy.   

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I believe the exhaust system is custom, and having it repaired/replaced is problematic. I've also heard stories about challenging COG issues. IMHO Missiles are a potential can of worms. If I wanted an IO-550, it would be attached to an Ovation.


As aways.....YMMV.

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Quote: airfoill

 Do you know which parts are specifically made by Rocket?  I was wondering if those parts are something a good aircraft fabricating shop may be able to make. 

I've had to to take some of my "orphaned" parts from the Rajay turbo system that I have to a fabricating shop to have repaired/remanufactured.

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Update!

I talked with Darwin Conrad at Rocket Engineering's Oshkosh display this year.  He's the owner and engineer behind the conversions.  According to him, the FAA required him to provide support for the conversion for 17 years, else they would not give him the STC.  He also said they still actively support the Mooney conversions, as they help cash flow for his turbine products.  Claims to ship parts every other day for Missiles and Rockets.

Finally, he said the company would STILL do a conversion right now if you want!  All for the cool sum of... (drum roll plase)

$129,000.

Gulp.

Quote: mooney205kd

One really big negative, in my view, is what Rocket told me when I was looking at a few of their conversions in 2005.  I asked how long they would continue supporting these, as they are now discontinued.  Their rep said "oh, 10 years maybe?"  That was 4 years ago.  Keep in mind that there are quite a few Rocket (and Missile) - specific parts in the conversion that only they make, so upkeep in the next decade may become sketchy.  Also, I think they only converted a handful of J's to the Missile, like 20 maybe?  Very limited numbers.

Another consideration, as Jim said, is the extra weight on the nose gear.  Be prepared to replace the doughnuts frequently, and be mindful of the condition of your nose gear.  It is now supporting much more weight than it was designed for.  I've heard pilots who've flown these say that it is sometimes difficult to get enough nose-up trim for landing, too.

Having said all that, I wish Rocket were still doing these.  We just did an overhaul on 5KD, and if this conversion had been available, I betcha we would have done it!  It would have made for a screamer!  But, fact is, it's an orphaned conversion, or at least will be soon.

 

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Thanks for that update Chris!  I'm glad to hear that they're still actively supporting the mods.  I think it wouldn't be impossible for an owner to spec out any of the custom parts in the future if/when they quit supporting it, too. 

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Hmmmm.  I can't remember who I spoke with at Rocket a few months back but he was the test pilot for the first Rockets and Missiles.  He said it could still be done but noone would want to do it because you could have an Ovation for less money.


 

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George,


Don't look now, but your F-18 tails are on backwards......


The Continental IO-550 is a spectacular power plant.  Blending it with a mid length M20J has got to be a fantastic combination.  The folks at rocket engineering must be forward thinking.  They at least can finish a good idea when they have one.


I love this thread....It ultimately supported my decision in favor of the M20R.


Best regards,


-a-

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Quote: carusoam

I love this thread....It ultimately supported my decision in favor of the M20R.

Best regards,

-a-

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I have flown a 252 Rocket for almost 700 hrs in the past 2 1/2 years with excellent results, the airplane flies like any other airplane just faster and better climb rates. I've heard that 1000 hrs were spent in flight testing and it shows, the cooling on hots days is excellent, I never see over 350 F on CHT once the fule flow was set correctly, the upper altitudes are where it really shows its stuff. I have not seen a turbocharged combo that works as well, usually critical altitudes are 20K +/_ this one is 24K before it starts to drop off max boost of 38" still climbing 1000'/min! This week I was showing a friend cruise climbs at 155 KIAS @900'/min continuously to 8,500' that's Aerostar numbers! in speed and climb (not the 700).


The concern about flairing is bogus, I regularly fly with 2 up front no bags to speak of with no problem in the flare. I don't understand the concern about parts there is nothing but a motor mount, a bulge in the cowl, and different exhaust system this is easily overhauled by any shop and 2 intercoolers that are unique, but they can be rebuilt easily by appropriate overhaul shops. Everything else is shared by P210, C340, C414, Baron 58TC, Baron 58P, over 3500 aircraft!


After flying an Acclaim back to back, the difference is a larger baggage area, no difference in rear seat room, no difference in speed and the G-1000 for 300 -400K more dollars. 


My Take:


Don Shapansky

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I have flown a 252 Rocket for almost 700 hrs in the past 2 1/2 years with excellent results, the airplane flies like any other airplane just faster and better climb rates. I've heard that 1000 hrs were spent in flight testing and it shows, the cooling on hots days is excellent, I never see over 350 F on CHT once the fule flow was set correctly, the upper altitudes are where it really shows its stuff. I have not seen a turbocharged combo that works as well, usually critical altitudes are 20K +/_ this one is 24K before it starts to drop off max boost of 38" still climbing 1000'/min! This week I was showing a friend cruise climbs at 155 KIAS @900'/min continuously to 8,500' that's Aerostar numbers! in speed and climb (not the 700).


The concern about flairing is bogus, I regularly fly with 2 up front no bags to speak of with no problem in the flare. I don't understand the concern about parts there is nothing but a motor mount, a bulge in the cowl, and different exhaust system this is easily overhauled by any shop and 2 intercoolers that are unique, but they can be rebuilt easily by appropriate overhaul shops. Everything else is shared by P210, C340, C414, Baron 58TC, Baron 58P, over 3500 aircraft!


After flying an Acclaim back to back, the difference is a larger baggage area, no difference in rear seat room, no difference in speed and the G-1000 for 300 -400K more dollars. 


My Take:


Don Shapansky

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 I absolutley love my Missile!  I have found it to be one of the most versitile aircraft I have flown/owned.  I can cruise at a TAS of 186 kts burning 16.5 gph or slow her down to 155 kts burning 10 gph (below 10,000).  If you're willing to go to 18,000, you can get 175 kts on 9.5 gph.  The aspect I like the most is the climb.  I flew out of Shreveport the other day with 75 gallons of fuel, myself at 215 lbs. and about 50 lbs. worth of equipment.  It was 5 degrees C, I climbed at 95kts indicated yielding 1500 fpm to 7500 then lowered the nose to 110 kts and held 1000 fpm to 9500. 

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Some models have a letter and a number (J - 201, K - 231)


Some have a number and a name (252 - Missile, 262 - Rocket)


Some have a letter and a name (M - Bravo, R - Ovation, S - Eagle)


Not sure what the Acclaim is...

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TN=Turbo Normalized  on your Continental IO-550  (to add to Jim's explanation)


Sometimes the M20L shows up in conversation, as it had been modified from Porsche power to an IO-550 also. 


Rocket engineering started the trend by putting large displacement continental engines into Js and Ks.  The Mooney factory responded with M20M (Lycoming TLH) and then M20R both based on the long body of the M20L (+ stretched rear window and stronger legs).


Best regards,


-a-

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Quote: eaglebkh

Some models have a letter and a number (J - 201, K - 231)

Some have a number and a name (252 - Missile, 262 - Rocket)

Some have a letter and a name (M - Bravo, R - Ovation, S - Eagle)

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I have flown three to four different Rocket and Missle conversions all with impressive performance for a price. Fuel. And lot's of it.


Most have cruzed around 180kts at 3500 or so. I would like move up from my J model but everytime I jump in a Rocket or Missle and see the burn I'm glad to be in the J.


If I could afford it though....................

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Quote: danb35

All Mooneys, except for the original M20 and the M22, have at least one letter (the Acclaim is the only one I know of to have two letters, the TN).  Most, but not all, have a name as well; for some of those, the "name" is a number.

The J is also known as (depending on when it was made, and what options were installed) the 201, the 205, the Advanced Trainer, and probably other things I've forgotten.  When Rocket Engineering bolts an IO-550 onto it, it becomes the Missile.

The K, from the factory, was either the 231, 252, or the Encore (most notable differences between these models are the engines--all are TSIO-360s, but the 231 was either a -GB or -LB, the 252 was a -MB, and the Encore was a -SB).  When ModWorks bolts the engine from a 252 onto a 231, it becomes a 262.  When Rocket Engineering bolts a TSIO-520 onto any of the K models, it becomes a Rocket (though I've never heard of a Rocket conversion being done on an Encore, and I understand they're pretty rare on 252s).

Missile, Rocket, and 262 are aftermarket names, not "official" Mooney designations.

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Quote: danb35

All Mooneys, except for the original M20 and the M22, have at least one letter (the Acclaim is the only one I know of to have two letters, the TN).

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