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Super 14

RVguy

Member
I would like to start a discussion on the viablity of this option. I understand that folks have been dropping IO 540s in previous RVs with great success so would the RV14 not be a suitable candidate.:confused:
I have read Vans article about VNE, larger engines and High speed flutter but if a closer eye is paid to the ASI so as not to exceed VNE then wouldnt this concern be alleviated.
What I am also interested in is the extra strenght needed to the structure and how that would be accomplished..I understand that with the Harmon Rocket and F1 Rocket this is done by purchasing a third party kit but would a regular builder be able to fabricate the necessary hardware/components to accomplish this.

ps..I do realize that no one has seen any of the plans or construction manuals yet so we would of course be speculating on all this.:rolleyes:
 
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Steve, it's a TAS matter, NOT an indicated airspeed matter.

Van wrote an article entitled, "The gauge that lies" and was directly addressing VNE issues and that they're related to TAS.

A search should turn up the article.

Best,
 
I would like to start a discussion on the viablity of this option. I understand that folks have been dropping IO 540s in previous RVs with great success so would the RV14 not be a suitable candidate.:confused:

The question begs to be asked..........WHY?
 
The question begs to be asked..........WHY?

Why would someone want to take a perfectly good Stits Playboy and:

-Replace the 75hp engine with a 125hp engine
-Redesign the cowl
-Enclose the open cockpit
-Replace the original externally strut braced wings with aluminum cantilever ones.

Hmmm....only an old fool would try and modify an experimental airplane.:rolleyes:
 
Why would someone want to take a perfectly good Stits Playboy and:

-Replace the 75hp engine with a 125hp engine
-Redesign the cowl
-Enclose the open cockpit
-Replace the original externally strut braced wings with aluminum cantilever ones.

Hmmm....only an old fool would try and modify an experimental airplane.:rolleyes:

Aw come on....I think we are beyond trite statements like that.

The RV-14 isn't even available and we are at least a year from a customer plane flying......even an experimenter needs to wait until the plane has field history before we talk about its "deficiencies".

My question of WHY still stands.
 
My question of WHY still stands.

Sam, you ask WHY?

I ask...Why not?

It does not have to mean that there is a deficiency in the stock RV-14.

We have some guy building a twin engine RV-6A. Not my cup of Classic Coke, but as long as he does it with sound construction considerations, why not?

We have a guy who wants to build an A model and operate off a grass/dirt strip with gopher holes. In my opinion, that is a tip-over waiting to happen.

Is a properly constructed Super 14 a safety issue?
 
I think we are beyond trite statements like that.

Nothing trite about my post Sam. Hypocrisy, now there's something we can talk about. Folks praise Vans all the time for what he's brought to the experimental world and he started this process by tinkering and modifying. In the case of the Stits, we're talking major modifications. But many of these same folks scoff at others when they want to modify their own RVs in ways that others may not agree with. It's experimental aviation for goodness sakes!

even an experimenter needs to wait until the plane has field history before we talk about its "deficiencies".

According to whom? And I don't think the original poster said anything about "deficiencies". He said "I would like to start a discussion on the viablity of this option."

In my personal opinion folks who experiment with their RVs are paving the way for the rest of us. Early RV-3 builder Art Chard's efforts led Van to the RV-6 and what about the pioneers of constant speed props and IFR cockpits. Vans never encouraged those things early on. Over the years there have been many "mods" to RVs that came from folks out in the field operating completely independent of the company and doing what Vans himself did back in the 1960s and many of these mods ended up benefiting all of us. Its good for our industry and its part and parcel to the spirit of experimental aviation.
 
Steve, it's a TAS matter, NOT an indicated airspeed matter.

Van wrote an article entitled, "The gauge that lies" and was directly addressing VNE issues and that they're related to TAS.

A search should turn up the article.

Best,


Thanks Pierre, I will look it up.
 
By "proper construction" I am also implying proper engineering as well. That gets it beyond my ability.
 
The question begs to be asked..........WHY?

Hey Sam, the best way for me to answer this question would be to say FUN! For me a big reason for embarking on this, my first homebuilt project is all the fun and joy experienced in the pre-planning, planning and researching aspect of this long educational endever. Yes it would be very easy for me to follow the status quo and build something exactly like everyone else but customization just seems better to me. Of course I do not want to re invent the wheel but its really cool to hear all of your ideas hear on VAF. This stuff really gets my brain in gear and Ive always been a dreamer.:rolleyes:
 
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Reading between the lines, the 14 looks like Vans trying to standardise things in an attempt, amongst other things, to improve the safety record of homebuilding. Bolting a big engine on an aeroplane is not like building a hotrod in the garage. Big mods like this make you an engineer and a test pilot. Regarding the process of experimental modification that led to the RV-1 - Vans is an engineer and modded the Stitts based on sound engineering decisions. His design philosophy is 'total performance', along with safety. designing an aircraft (or anything for that matter) you should have clear design goals and the skill to make the appropriate engineering decisions to achieve them. 'Just for fun', is not a precise enough goal. Aviation is an extremely unforgiving environment - I know, I have lost quite a few friends in the industry. One modification, error, mistake etc can have a whole set of flow on effects that end in a smoking hole in the ground. That smoking hole does not equate to 'fun' for you or the poor sod sitting beside you.

If the 14 does not meet your mission goals and you don't have the skill to engineer a proper modification, then you should pick an aircraft that someone else has designed and proven that does meet your needs.
 
Reading between the lines, the 14 looks like Vans trying to standardise things in an attempt, amongst other things, to improve the safety record of homebuilding. Bolting a big engine on an aeroplane is not like building a hotrod in the garage. Big mods like this make you an engineer and a test pilot. Regarding the process of experimental modification that led to the RV-1 - Vans is an engineer and modded the Stitts based on sound engineering decisions. His design philosophy is 'total performance', along with safety. designing an aircraft (or anything for that matter) you should have clear design goals and the skill to make the appropriate engineering decisions to achieve them. 'Just for fun', is not a precise enough goal. Aviation is an extremely unforgiving environment - I know, I have lost quite a few friends in the industry. One modification, error, mistake etc can have a whole set of flow on effects that end in a smoking hole in the ground. That smoking hole does not equate to 'fun' for you or the poor sod sitting beside you.

If the 14 does not meet your mission goals and you don't have the skill to engineer a proper modification, then you should pick an aircraft that someone else has designed and proven that does meet your needs.


+1, Two Thumbs up, etc.....

I agree that the freedoms of the experimental category are what got us to where we are today, but there is far to much TLAR engineering that goes on.

Over the years I have seen countless #'s of highly modified RV's where the builder wasn't an engineer, but said all of the "calculations" had been done (though I can't think of a single instance were a builder / modifier ever offered any documentation or other information that would substantiate that claim).

There is so many factors that can be effected by a seemingly simple modification. Without a very detailed look at how the mod. integrates with the whole design, it is very easy to miss something that might be significant.

Example: In the near future, the RV-14 design will be put though dynamic testing of the landing gear. A change such as a 6 cyl engine would cause major moment of inertia change (among other things) that would most like totally negate any testing that was done based on the IO-390 being the biggest/heaviest engine. Considering the amount of effort required to complete these tests, it is highly unlikely that anyone would repeat them after doing such a modification.
The main point of this, is to emphasize that someone may be pushing much farther into the experimental fringes than they would at first believe.
 
I can only imagine these are the same type of arguments/discussions held when someone first decided to put a 540 on front of a 6, 7 or 8... I suspect it will happen with the 14.
 
I can only imagine these are the same type of arguments/discussions held when someone first decided to put a 540 on front of a 6, 7 or 8... I suspect it will happen with the 14.

I am sure it will happen, but I just hope that whoever does it makes an informed decision, and that the modification does not have serious unexpected consequences. I understand there needs to be a balance between the freedom to do what you like and sufficient regulation to prevent people from unwittingly injuring themselves or someone else. I don't live in the USA, but the latest kitplanes magazine seems to infer that the FAA are starting to look at the accident rate of homebuilt experimental aircraft. I also see that Vans is leading the group of experimental kit manufacturers trying to improve the safety of the industry. I see the standardisation of configurations of the '14 as piece in that picture. In fact, I have been 'lurking', wanting to build an RV for about 20 years. Life's circumstances have gotten in the way and it has not happened. I will be able (I hope, if my airline does not implode in the next year or so) to finally start. What made me say 'the 14 is the one' is the very standardisation discussed above. I have seen various accidents and incidents caused by what would appear minor aircraft modifications or minor changes to procedures.

I don't want to 'rain on anyone's parade'. If you have the skill and talent to modify an aircraft, and you are informed about the risks, and you accept that - then go right ahead. As a professional aviator for the last almost 30 years, I have seen that it is 'what you don't know' is what has the potential to kill you.
 
Sam,

I have a good reason why. 540's rated at 230 hp and 260 hp are commonly available. I like the 390 ALOT (initially wanted one for my -7 but at almost $40,000 it is cost prohibitive).

If one were to locate a 230 hp (derated for mogas is a good thing) 540 on the cheap wouldn't that be a good cost effective fit?

I do know that the 540 would be slightly more hp and somewhat heavier than the 390 that Van suggests, but probably not a bad choice if CG issues and proper diligence is given to the change.

Now, I know that I am an armchair engineer with no real experience in the matter... but how bad would that be?

:confused: CJ
 
A quick google shows about 130lbs difference in weight. This extra weight is well forward. What would your new 'G' limits be? - with the reduced useful load, could you do aeros 2-up? With the higher fuel flow and reduced useful load, would range be acceptable? What is the effect to A/B ratio? All that weight forward could significantly change the spin characteristics of the aircraft. So, putting a bigger motor in may make it go faster, but will you still be able to do aeros in it safely? If it flicks into a spin when manoeuvring, will it recover? Who is going to test it to find out?
 
Reading between the lines, the 14 looks like Vans trying to standardise things in an attempt, amongst other things, to improve the safety record of homebuilding.

Refer to Table 1 here:

http://www.rvflightsafety.org/safetyprogram/introduction/

Embedded in unknown or mechanical failure causes might be an isolated event that you refer to above. As I see it, the vast majority of fatal accidents are still due to pilot error.

In recent years, we have had at least two incidents attributed to fuel lines coming loose. Most likely they were not properly torqued.

That has nada to do with the size engine. It was a failure at multiple times for more than one person to check those critical connections.
 
Thanks Ron,

My comments (not being a resident of the US) are based on the articles I have read. I am not saying putting a bigger engine is inherantly more or less dangerous, just that it is unknown what the effect will be without some thoughtful analysis.

To diverge slightly from the discussion, my wife mentioned to her dad who lives in Florida, that I was going to build an RV. His response was 'didn't John Denver die in one of those?' Trying to educate her on the causes of air crashes, we looked up this report http://www.avweb.com/other/ntsb9905.html

It is an interesting read and highlights the dangers of modifying a design. The builder made a number of modifications including a larger engine and changes to the fuel system. Without going in to too many details, the 'safety feature' modification of not having the fuel lines transit the cockpit and the resulting fuel valve positioning was probably the cause of the crash.

The point I am trying to make is that with freedom comes responsibility. The guy that built the long-EZ and made the modification was not the one who paid with his life, but someone did.
 
Sam,

I have a good reason why. 540's rated at 230 hp and 260 hp are commonly available. I like the 390 ALOT (initially wanted one for my -7 but at almost $40,000 it is cost prohibitive).

If one were to locate a 230 hp (derated for mogas is a good thing) 540 on the cheap wouldn't that be a good cost effective fit?

I do know that the 540 would be slightly more hp and somewhat heavier than the 390 that Van suggests, but probably not a bad choice if CG issues and proper diligence is given to the change.

Now, I know that I am an armchair engineer with no real experience in the matter... but how bad would that be?

:confused: CJ

A quick google shows about 130lbs difference in weight. This extra weight is well forward. What would your new 'G' limits be? - with the reduced useful load, could you do aeros 2-up? With the higher fuel flow and reduced useful load, would range be acceptable? What is the effect to A/B ratio? All that weight forward could significantly change the spin characteristics of the aircraft. So, putting a bigger motor in may make it go faster, but will you still be able to do aeros in it safely? If it flicks into a spin when manoeuvring, will it recover? Who is going to test it to find out?

As much as it may be difficult for some of us frugal builders to accept, Vans has entered a different economic environment with their latest aircraft (RV-12 excepted). The RV-10 and RV-14 are not intended for the builder who scrounges for "bargains" the way many RV-4 and RV-6's were built. It was often a badge of honor to see how frugally an RV-4 or -6 could be built, but not so with the -10 and -14. These "big" planes are targeted at builders with the funds to build a serious aircraft with top-notch equipment. Why build a plane that costs $100+ and try to "save" with a "bargain" engine that is outside the design envelope?

We saw this when the RV-10 first arrived. Builders with RV-6 mindsets jumped into RV-10 projects without calculating what this plane was going to cost if equipped for the mission most pilots expect from it. The plane was bigger, more complex and more expensive than some of the early builders realized. Some projects found new homes.

Same scenario with the RV-14. A builder should be prepared to spent major $$$$'s to build the plane as designed. If that budget isn't available, the builder might be better served by a plane that fits the available budget.

Having said that....yes.....a 540 will be on the nose of an RV-14 soon after the kits are released. We can't help ourselves. :)
 
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The RV-10 and RV-14 are not intended for the builder who scrounges for "bargains" the way many RV-4 and RV-6's were built. It was often a badge of honor to see how frugally an RV-4 or -6 could be built, but not so with the -10 and -14. These "big" planes are targeted at builders with the funds to build a serious aircraft with top-notch equipment.

Sam, maybe you are right on the RV-10. I just do not see that with the RV-14. From my limited understanding of the -14, it appears to really only offer three inches more shoulder room over a RV-7.

Extra gas...Big whoop. I can't fly that long.

No doubt there are well-equipped planes of every model so the platform is certainly not the driver.

I just read Vans write up on the RV-14 and here is the only thing that I noted that defines the rationale of the plane:

"The RV-14 cabin accommodates full-sized adults — in fact, the basic idea was to provide RV-10 room and comfort in a two-seat airplane. The results are impressive. Both seats will hold people at least 6’4” tall and provide them with truly comfortable leg and headroom."

It appears to be for bigger people.
 
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+1, Two Thumbs up, etc.....

I agree that the freedoms of the experimental category are what got us to where we are today, but there is far to much TLAR engineering that goes on.

Over the years I have seen countless #'s of highly modified RV's where the builder wasn't an engineer, but said all of the "calculations" had been done (though I can't think of a single instance were a builder / modifier ever offered any documentation or other information that would substantiate that claim).

There is so many factors that can be effected by a seemingly simple modification. Without a very detailed look at how the mod. integrates with the whole design, it is very easy to miss something that might be significant.

Example: In the near future, the RV-14 design will be put though dynamic testing of the landing gear. A change such as a 6 cyl engine would cause major moment of inertia change (among other things) that would most like totally negate any testing that was done based on the IO-390 being the biggest/heaviest engine. Considering the amount of effort required to complete these tests, it is highly unlikely that anyone would repeat them after doing such a modification.
The main point of this, is to emphasize that someone may be pushing much farther into the experimental fringes than they would at first believe.

I totally agree, and the sheer inevitability of the mod puts Vans in an invidious position. I hope Vans will do the engineering and endorse the option.
 
I have read that the 14 has incorprorated the engine mount and nose wheel gear from the RV 10, the RV 10 has had no issues, at least that i'm aware of with nose wheels collapsing, the suspect nose wheel is why some (loveable) RV nut has not put a heavier 540 in an Vans A model a long time ago.

If a 260 hp, 540 powered 14is flown within the design limits etc - whats the big deal ?

One thing is certain, and make no mistake about it - there will be 540's in RV 14's, its just a matter of when.


P.D.
 
I suppose the drop test would certainly stress the engine mount attach point structure with the moments augmented by an extra 150lbs on the engine mount. This would be substantially worse for a tailwheel version (versus the tricycle) where the gear legs also attach to the engine mount in the rv-3,4,6,7 style. Possibly one reason why we don't see a tailwheel RV-10.
A '540 'A' model would still be nice though!
 
I have read that the 14 has incorprorated the engine mount and nose wheel gear from the RV 10, the RV 10 has had no issues, at least that i'm aware of with nose wheels collapsing, the suspect nose wheel is why some (loveable) RV nut has not put a heavier 540 in an Vans A model a long time ago.

If a 260 hp, 540 powered 14is flown within the design limits etc - whats the big deal ?

What you have heard is not what was said.

The RV-14 has the same style engine mount / nose gear leg.

That should not be considered to mean that it is the exact same assembly.
It is not. It is a new part specifically designed for an IO-390 on an RV-14.


Even if it was the same assembly, it wouldn't mean that a 540 would work fine, since the engine mount has to attach to the rest of the airframe and transmit those additional loads.

No one would assume that a bridge designed for a maximum load of 15 tons, but was built using the exact same middle span section that was used on a 30 ton rated bridge, would make the entire bridge rated for 30 tons.

Same principal applies to airplanes......
 
The O-540 comes in several flavors, and a well selected model, stripped of vacuum pump and sporting a flyweight starter, alternator and a wood prop would take about half the sting out of it.
I advocate lightness and simplicity. The O-540 does not meet the lightness, but a fixed pitch prop does meet the simplicity.
I wonder how the O-540 FP would compare to the O-390 CS in heads up performance, and lifetime cost?
 
The O-540 comes in several flavors, and a well selected model, stripped of vacuum pump and sporting a flyweight starter, alternator and a wood prop would take about half the sting out of it.
I advocate lightness and simplicity. The O-540 does not meet the lightness, but a fixed pitch prop does meet the simplicity.

A fixed pitch wood prop on an (I)O-540 engine with the speed performance range of this aircraft would be a total unknown and perhaps a ticking time bomb. I've seen the results of wood props on 200HP RV applications disintegrate. Both pilot and pax were lucky to walk away from that one. The forward end of the aircraft was substantially damaged all the way back to the fuel tank attach points...
 
I too would like to see Van research, develop, and offer, a RV-14 with a -540

People ask, "Why?"

I'll answer that....

http://flightaware.com/live/flight/N84MF/history/20121107/1830Z/KMCW/KEFD

I have always known what my next airplane would be, but since buying my Rocket, I am at the end of the line.... There is no place to go up from the Rocket without having a 70 knot stall speed, and zero tolerance for wing contamination. The Lancair, SX300 and Questair are not acceptable solutions for me....

On a trip like the one above the Rocket is a single place airplane unless you have a small passenger.... I am not commenting on my wife's size, she is not a large person, but she is not going to sit in the back of a Rocket for 3.5 hrs.

Further, am not aware of anyone who has a Rocket with good cabin heat in the back seat....

I would hate to give up the fighter feel and center line seating of the F-1, But if Vans would offer a RV-14+ which was -540/-550 powered and retained aerobatic capability, I would probably have found my next airplane.....

I am not interested in an Super-6/7/14 that was nothing more than a -540 bolted on a stock airplane.... If Mark, or Harmon or someone else engineered a modification, that would be my second choice.....

Tailwinds,
Doug Rozendaal
F-1 EVO
 
With the 14 in the final design phase, now would be the time for Van to make the changes needed to give it the option to use the 540/550 engines.

Which makes perfect sense because so many potential buyers have expressed a desire for a -540/-550 powerplants.

Whether Van steps up with a beefed up -14 to handle the extra needs for the bigger engine is not yet known but it would be a very smart move on his part.

Just look at his product successes when he listens more to the market than himself:

RV-4, RV-6, RV-7,RV-8, RV-9, RV-10, RV-12 These models were influenced by market demands but with resistance at times.

But when he gives the market the plane it wants, he is highly rewarded.

The comments writted here prove that there is a demand for a more powerful 2 seater in a side-by-side with all those great RV characteristics.

Upgrading the -14 design for a 540/550 should not be a siginificant undertaking either in design or analysis or money.

And I'm convince the money would follow if the option is made available and will solve all the problems of having people build one on without factory support.

From the Legal/PR stand point, go ahead and beef-up what ever is needed, offer the option and you're in the clear. Sell lots and lots of kits and the various sundrys and make lots and lots of $$$$$$$$$ and live even more happily ever after.

Glenn654

PS Besides some extra power would be very useful in getting Mr & Mrs Bubba
off the ground plus baggage and fuel
 
The spin characteristics would be significantly different with the 540, due to its extra weight and length and moments of inertia about the aircraft's center of gravity.

And some of these same factors will influence the stability of the airplane, even if the center of gravity is within the range originally specified by Van's.

Like the effects on the structure, these other effects will generally be negative.

Bottom line, if you're serious about this, start studying aeronautical engineering now. There's a LOT to learn.

Dave
 
Just for kicks

I have often wondered what a -14 would be like if you put the longer -10 wings on with a 540 in the nose? Somewhat like a large super -9? Obviously not used for aero, but I wonder what the cross country characteristics would be like up high? Would probably see somewhat better range from the increased span, no?

I am planning on building a pretty stock -14, this is just a mental exercise!
 
Guys have put Allison V-12's in Camaro's and so on.

An IO-540 in a -14 is not nearly as radical as an IO-540 in a -6. I've flown a couple of Super -6's and it's a blast.
Not everyone likes vanilla.

Done correctly, I'd be a buyer too,

Best,
 
There are assemblers and there are builders. A builder like Van would look at a Stitts Playboy and think, "how could I make this better"? Would a 540 necessarily make a RV14 better? We will not know until a builder figures it out, flies it and gives a progress report. I suspect we will not have to wait too long for that report.
 
Sorry to revive an old thread. For the past few years I've been doing research about building a Super 8 (as documented in articles like this Super 8 FAQ and this flying report). However, recently my wife, aka family CFO, aka "the boss", expressed a desire to see something other than the back of my head when we go flying. Hence, a search for fast side-by-side designs began.

Anyway, after a little searching I found this old thread. It's been more than a few years since the last post...

Has anyone started building a Super 14 yet? Would love to hear details about your ideas, mods, etc.

In an era where a rebuilt 540 costs about the same as a new 390, a Super 14 sounds like a reasonable idea.
 
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Instead of a Super 14, why not build a two seat version of the 10? Most of the engineering is done already, gives plenty of baggage space, ability for O2 tanks...

Tim
 
Instead of a Super 14, why not build a two seat version of the 10?

Well, then you would just have an RV-10 with two seats removed, and you wouldn't be able to call it 'Super'. It would be like a 'Half RV-10' which sounds decidedly uncool :D
 
It needs to have a taildragger option too!!!

The allure of a super 14 for me is the ideal of fast, comfortable, good panel realistate, decent stability, and best of all aerobatic capability. It could be a rocket with a sister by side comfortable cabin.
 
I was a potential customer when the F2 Rocket mockup was shown at OSH a number of years ago, for the reasons mentioned early in this thread: A bit more performance, quite a bit more room, more baggage capacity, but primarily because the 6 cyl engines were so much cheaper than angle valve 360's back then (pre -10 days).

Mark, care to make the F2 design & files open source? There are lot's of places that will punch out aluminum stuff cheap these days.....

Charlie
 
Is it really as easy to create a "Super" RV as they say? In theory a Super 14 shouldn't be too hard. In the Super 8 FAQ they say:

Q. What has to be done to convert a regular RV 8 to a Super 8?

A. My favorite question because the answer is so simple. Shorten the engine mount, lengthen the cowl, throw the battery in the tail to keep the CG in range, and go fly. Seriously. That's it.

Supposedly (?) Super 8's are safe as long as you perform aerobatics in the normal RV acrobatic speed range (roughly 150 mph). Maybe with a little less fuel onboard to compensate for the extra 100 LB in the nose. But when you're done wringing it out, you can throttle up the big 540 and cruise at 230 in a straight line, or climb at 3,000 ft/min.

Would love it if the same were true in a Super 14. For me, a Super 14 would be the ultimate airplane -- unless I win the lottery. ;)
 
Well, then you would just have an RV-10 with two seats removed, and you wouldn't be able to call it 'Super'. It would be like a 'Half RV-10' which sounds decidedly uncool :D

Not true! You can call an amateur-built aircraft anything you want.
 
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