4-cylinder RV-10

[paul330]

Hi guys - new to this game - one of the first few RV10 builders in the UK.

I have seen the previous discussions on RV10 engines and I know the official VANS view - the RV10 flies behind 6-cylinders. However:

- fuel is expensive, and getting more so - especially in Europe
- by all accounts, the 540 makes the 10 a little nose heavy
- the 10 is designed for 210 -260hp so what's wrong with a Barrett390@210 or a XP400@220?
- one of those will save some $8k on initial cost
- you get an extra 50-100lb payload
- you only need the 540 performance out of short strips
- cruise performance is not down hugely

Downsides:

- adequate rather than stunning performance
- probably less smooth

VANS are quite happy to support all the after-market 320 and 360 engines for the 7/8/9 with their FWF kits so why not the 10? Seems to me they just have some sort of mental block about it. So, since I work in Hong Kong and live in UK how about one of you guys in the US do a bit of ear-bending at the VANS stall at Sun'n'Fun!! Love to be there myself........

Paul
G-RVVY
Empennage

 

[Kyle Boatright]

I've spoken with the folks at Vans during Oshkosh and SnF about continuing development of the -10 with the smaller engines they planned when the aircraft was introduced, or even the "big" 4 cylinder Lyclones. Their answer was that there doesn't seem to be any meaningful interest from customers in installing a smaller engine. They said if they were getting numerous customer requests for a firewall forward solution with a smaller engine, they would develop one.

One of the hurdles they mentioned was the cost of developing the "small engine -10". Presumably they would need to build yet another $100,000 prototype (or spend $50k converting one of their existing planes), then would need to go into production with a new motor mount and cowl (at the least). That's no small investment if they believe the market is tiny.

So, find a hundred like minded souls who want an RV-10 with a smaller engine, get 'em to write/call/petition Van's, and maybe, just maybe, they will look into it.

 

[Captain_John]

This could be the platform for a high output IO-390?

Take the 8.7:1 pistons out and pump it up a bit. With a few more tricks, I and sure one could eek out another 15 hosses.

That would make the conservative 210 HP engine 225 HP and should propel the -10 nicely!

What do you think?

CJ

 

[Mel]

I agree whole heartedly that lighter is better. However, that's not the whole equation. Especially on a 4-seater. If you go to a lighter engine an still want to carry things in the back seat or behind, the engine will have to be moved forward to control the aft CG. It's the same old thing; one modification begets several more. Or like Rozanne Rozannadana used to say, "It's always something!"

 

[jclark]

vans published performance specs,for the 210 hp rv-10,look comparable to the mooney 201 or the 4 place bonanza retractable's.the 210 hp rv-10 looks better for high altitude airports.maybe,when avgas is $5 average,the 200/210 hp will look more attractive? also,vans always encourages a liteweight rv.a smaller engine rv-10 looks like good or very good to me? or is the resale value the big hit??

A caouple of things to consider ...

1. Van's did a "smaller" engine but there obviously is not enough demand for that for them to proceed. They probably get more people wanting MORE than the 260 or so HP "540".

2. When "Van hisself" (with his brother) decided to build an RV10, what did they put in it ?

"... The engine is an AeroSport Power IO-540-D4A5 with a Hartzell Blended Airfoil prop..."

From flying with friends who have larger engines (these are all 2-place RVs) , I find that there are many times when they burn **LESS** fuel that me on the same trip travelling at the same speed. In this case it is simply the case that an O-320 and an O-360 use about the same amount of fuel to generate say 150 HP. Then other things come into play on the fuel economy. Fuel savings at the same speed, using a smaller engine, is probably an overblown expectation for many.

(By the way, I used to demonstrate the same thing flying my 180 HP Archer II on trips with a friend in his 150/160 (?) HP Cessna 172. We would compare fuel consumptions at the fuel stops and I would often come up a few tenth's of a gallon less. )

Also remember that weight up front, helps with putting weight in the back.

 

[fmarino1976]

4 Cyl engine

Paul, I'm with you on this one. From what I've seen on RV-10 published W&B, I also think that a smaller engine up front would make it less nose heavy. I've looked at the xp-400 from superior, or even the 250 hp version. It gets almost the same hp than the io-540. Even if fuel consuption is the same, I still like the idea of a lighter airplane altogether.

I'm still a ways off from starting, so I hope Vans will offer us more choices by then. If I'm not mistaken. One of the RV-10 prototypes has a 4 cyl in it. I read that in this forum from someone who flew it.

In any case, if you want to do it, I'm pretty sure there are a bunch of great guys here that would pitch in some know-how to help you out. Besides, that is why we all are going the EXPERIMENTAL route.

 

[Jekyll]

If I'm not mistaken. One of the RV-10 prototypes has a 4 cyl in it. I read that in this forum from someone who flew it.

N220RV sports a Continental IO-360. Though it is 210 HP, it is a 6 banger. It flies very nicely on 210 HP.

Jekyll

 

[Phyrcooler]

4-Cylinder RV's

I've said it before... and I'll throw it out again... I think there is room in the RV lineup for folks that need a bit more room for cargo/3rd passenger-kids-dog, etc., than what the RV-7 offers. Not as big/expensive as an O-540 propelled RV-10. I'm talking tip-up or slider canopy, O-360 power along the lines of a "stretch-9". A "2+2" with a small back seat. As I have mentioned to Van's - a "Tiger with a stick and RV qualities".

JMHO. I know It would fit my needs perfectly.

 

[Scott Will]

Ohhh man, you are sooo correct about a modified/stretched RV-7/9. A small backseat for our youngster would be perfect for us. The RV-10 is just a whole lot more airplane in terms of size and money. You could almost build 2 RV-7/9's for the price of a nice -10.

So there you go, teach the wife or kids to fly!

 

[gmcjetpilot]

May be not as good as you think

- the 10 is designed for 210 -260hp so what's wrong with a Barrett390@210 or a XP400@220? Paul G-RVVY Empennage

Hey mate, this was discussed to death a year or two ago (check the archives).

I agree the IO390/XP400 would fly horse power wise on paper, but you would need a new custom "stretched" engine mount. Don't count on Van making it. Also CG wise you may go in the opposite direction, ie tail heavy.

Bottom line you will not save much gas or money. IO390's and XP400's are not cheap to buy (new only) or economical on fuel. HP is HP. Fuel flow per HP is fuel flow. These engines don't have far supiour spacific fuel consumption or fuel burn per HP. You can just run a 540 at say at no more than 80% at any time, including take off.

A 540 can be operated economically with a careful throttle hand. In theory and in practice (ask the Rocket guys) you can burn the same or some claim less fuel with the 540 verses the 320's/360's; its all about those little black and red knobs (and the little blue one as well).

If you are at light weight, take off with 75% and fly with even less power. When you fly 4 adults with bags, on that hot wet day, you'll be glad you have the extra pony's in reserve.

Also the 210/220 HP 4 cylinder engines are a little more high strung and have higher compression than the 540. Gas wise if you are going to use the 95 UL or 93 UL you have there in "the continent", you'd be better off with the 540.

The RV-10 is designed for the 540. The extra effort to adapt and use your own engine choice (4-cyl) may be more effort than its worth. You will have to engineer and adapt. However it could be done no doubt. I am sure you are familure with the Piper Comanche single engine retract. That one airframe was made with O360 (180hp), O540(250HP) and even the IO720 (8-cylinders!). I have flown the first two. They both are nice, but lets face it, there is "No replacement for Displacment". Here is the real deal, Van will not support you. You are on your own.

The 540 engine is being cloned now, so the new price is not too bad. In fact I don't think its much more than the hot 4 bangers. There is always that dream of a cheap 540 core, sitting in a hanger or barn, you can get for a steal; than with a do-it-yourself engine rebuild, you have a enexpensive engine. Heck in the late 80's and early 90's, before the Rockets and F-1'sgot real popular, you could get used 540's cheaper than a 320 or 360. No kit used them. The Glasair used the angle valve heads 540's.

 

[paul330]

Hmmm Some good points there. Run the 540 derated and only use the excess when you need it. Don't know why I didn't think of that - I do it every day in the A330! Find all this stuff about HPs confusing - total of 150 hours on pistons out of 12000+, and that was over 30 years ago!!

I also guess the CG thing is better nose heavy. Then you only need ballast in the baggage compartment when you are 2 up and not payload critical rather than in the nose when you are 4 up and weight is at a premium.

Finally, in UK there is no experimental category as such. Any deviation or mod needs to be properly researched, submitted and approved. If VANS won't support it, it basically ain't going to happen.

540 it is I guess - way cooler anyway, especially with a 3-blade prop - shall we start THAT discussion again?

 

[w1curtis]

From flying with friends who have larger engines (these are all 2-place RVs) , I find that there are many times when they burn **LESS** fuel that me on the same trip travelling at the same speed. In this case it is simply the case that an O-320 and an O-360 use about the same amount of fuel to generate say 150 HP. Then other things come into play on the fuel economy. Fuel savings at the same speed, using a smaller engine, is probably an overblown expectation for many.

(By the way, I used to demonstrate the same thing flying my 180 HP Archer II on trips with a friend in his 150/160 (?) HP Cessna 172. We would compare fuel consumptions at the fuel stops and I would often come up a few tenth's of a gallon less. )

Also remember that weight up front, helps with putting weight in the back.

[/size][/font]

In which of the 11 dimensions and infinite universes do the above laws of physics (for many times when they burn **LESS** fuel ) apply? What exactly does any of your above comparisons prove other than you get different fuel flows in different aircraft, with different engines, with different pilots? It seems every few months or so this discussion pops up and this argument is put forth. It's a wives tales that seem to perpetuate.

Let's assume the fuel flow on a six cylinder 260 HP 540 producing 150HP is exactly the same as 210 HP IO-3X0 also producing 150 HP. Of course this is a generous assumption since the additional friction of the two extra cylinders would make it less efficient than the 4 cylinder at those power levels. How then could carrying around the additional weight of the 540 cause you to burn *** LESS *** fuel? I'd like to know cause fuel is expensive now and we may be on to something here

And by the way, conventional (non canard) planes fly faster and more efficient (though not safer due to stall characteristics) with a REAR ward CG. Less negative lift needs to be produced by the HS which in turn means less total lift required by the wing, which means less total drag on both the wing and the tail.

 

[Mike S]

Better get out the old rain gear Bill, I think there is a flood a'commin.

Mike

 

[w1curtis]

Better get out the old rain gear Bill, I think there is a flood a'commin.

Mike

Thought the earth wouldn't be visited by flood again. I have my flame suit all prepared.

 

[Rotary10-RV]

Thought the earth wouldn't be visited by flood again. I have my flame suit all prepared.

William,
I agree with you. If otherwise identical planes flying at the same speed and alt. the lighter plane should REQUIRE LESS POWER. That is if everything else is the same. In practice the well set up 540 won't require a lot more fuel. I believe that at a fast cruise drag starts being a higher factor than lift. So the difference is small, but should still be less with the lighter plane. See I didn't even bring my flamethrower!

Bill Jepson

 

[ScottSchmidt]

CG

The real issue you will have to deal with is CG. The RV-10 is already very sensitive to CG (especially when you load it!!!). When I fly with four people I ALWAYS make sure I have full fuel and I fill up every time I stop. If you put a 4 banger up front you will still have to add 100 lbs of balast just to keep the nose down. I had my plane fall back on the tail while loading it once. The plane was within CG with 50% of the fuel burned off but you have to be careful when you load. I posted this in another thread but I had two people in the back seats, and myself and other person both stepped on the step (which is located behind the rear passengers) at the same time (while pulling back on the cabin as well while stepping in) and the plane rocked back onto its tail and cracked my bottom fiberglass on the rudder. Now, when I load I put one in the back, one in the front, one in the back, and then me. Never had a problem.

The takeoff is quite different when you rotate with 2 or 4 people as well. Rotate with 2 people takes a good pull to get it up then forward to hold it just right. With 4 people, you move the stick 1/4" and the nose jumps. I really think the plane flies better with 4 people but without a 540 up front you would have a good 2 or 3 person plane unless you built an extension on the motor mount to hang the engine out further.

You may save $30,000 in fuel over a 2000 hour period but having all that horsepower sure is nice.

Van was going to offer the smaller engine but the majority of the survey's came back with the IO-540 box checked.

Plus, the first person that builds a 4 banger RV-10 gets the label "Slowest RV-10 ever built" Nobody wants that on their record. hahahaha

"there are just two ways to go....livin' fast or dyin' slow" -Robert Earl Keen

 

[rvbuilder2002]

The real issue you will have to deal with is CG. The RV-10 is already very sensitive to CG (especially when you load it!!!). When I fly with four people I ALWAYS make sure I have full fuel and I fill up every time I stop. If you put a 4 banger up front you will still have to add 100 lbs of balast just to keep the nose down. I had my plane fall back on the tail while loading it once. The plane was within CG with 50% of the fuel burned off but you have to be careful when you load.
You may save $30,000 in fuel over a 2000 hour period but having all that horsepower sure is nice.

Scott,
Thank you for posting true experience and debunking the myth that the RV-10 with a 540 Lyc. is nose heavy.
If you want a four place airplane with true utility for 4 adult people, you have to give at one end to accommodate the other.

As for better operating economy with a four Cyl... install the economy mod on an (I)O-540 (Index finger between throttle knob and instrument panel when pushing fwd for takeoff).
True, you will be carrying some extra engine weight around, but you have the extra power to use on occasion when you need it.
Besides, as Scott just described, if you installed a four cyl (even pushed fwd on an extended mount) you will likely be C.G. limited which will effect what you can carry for payload in the back seats and baggage area. In essence, the added useful load you gain from the lighter engine will be for all practical purposes, unusable.

 

[frankh]

UK fuel?..Ouch!

Would it not make sense to run a low compression 540 and use mogas as much as possible? (is that allowed in beaurocrat riddled UK these days?).

Considering there really is not very far to go in the uK then most of your flying can be done with mogas from your home airport.

Just a thought from an Ex-pat

Frank

 

[Andy_RR]

new engine mount - new opportunites

Surely if you have to make a new engine mount for the O390 in the RV10, the solution to the CoG problem would be to move the engine forward. OK, so a new or modified cowling would be required, but you're in real experimental territory anyway... You could do some clever stuff whilst your at it to improve cooling drag that little bit more.

A

 

[rv6ejguy]

It is important to note that the 4 cylinder would have to be moved forward something like 8 inches. The longer cowling might have impact on directional stability and I can assure you that you'll expend a lot of time building a custom cowling, mount etc. If this is really what you want, fine, but I don't see building a -10 with 4 seats and having inferior performance, especially in the climb at higher weights.

 

[ScottSchmidt]

I don't get it!

I had a friend call me from Sun N' Fun all excited about the SMA diesel engine. There is ALWAYS a discussion about alternative engines or diesel engines on a forum. I know people are looking for the Holy Grail in engines but for now the Lycoming is it. And now people want to put a 4 cylinder engine in their airplane to achieve that lower fuel burn. Why would you not want to most horsepower you can get and use an engine that has proven reliability? There are two things you can never have enough of horsepower and money.

Horsepower = Safety

The more horsepower you have the safer you will be when you need to go around, or takeoff on a hot day, or the need to climb above some rain or a storm.

Again, the fuel savings is not that much in the big picture.
The average RV-10 cost is in the $130,000 range. Insurance will be $3500 per year, hanger rent is $3000 per year. Lets say you fly 200 hours per year and fuel is $4.50 per gallon. The IO-540 will burn 13 gallons per hour and the 360 or 400 will burn 9. That is $3600 per year in extra fuel for the IO-540 or $300 per month.
You can definitely pull the throttle back as well. The difference in engine friction is not that much, OK let?s assume it is 1 gallon per hour more because of friction. So now you will spend an additional $16 per month in fuel based off 200 hours/year to have that extra power when needed. Then there is re-sale, you will have a hard time selling a highly modified RV-10. Not to mention your insurance actually might be higher because of deviations to plans.

If all you want to do is save fuel then get an RV-7. Before you really decide on a 4 cylinder, you need to go load up an RV-10 with 4 people and take it right up to 2700 lbs. at an airport that is above 3000 ft elevation. Make sure the OAT is above 85 degrees and then takeoff and see if you would feel comfortable with 20% less power. The current RV-10 has 10.38 lbs/hp with an IO-540. If you had a 210 HP engine, you could only have a gross weight of 2180 lbs to achieve that same 10.38 lbs/hp. The empty weight of a light RV-10 is 1600 lbs. Therefore with full fuel you would have a useful load of 220 lbs to achieve the same IO-540 lbs/hp. Anything over that and you will really start seeing a decrease in performance.

Just like anything, go fly a few planes and see what you think. I know everyone I talk with about these issues never go and fly. It is all imagination flying and dreaming of the idea plane ? 200 mph with 4 people burning ? cup per hour. Fly an RV-10 and then go and fly the 4 place Diamond aircraft. It has a 4 cylinder and will give you a good idea on speed and climb performance as compared to the RV-10.

Here is the fact! Flying is expensive no matter how much you want to ignore it. I love what Kirby Chambliss said in his interview in the Pilot Journal when they asked him what it takes to win the National Championship, "All the time and money you have!" Sean Tucker has said the exact same thing but it was more like, "Figure out how much you need and then multiply it by 2." Flying experimentals are the exact same. If you are on the edge of affording an RV-10 but it looks like you will squeak by with installing a 4 cylinder engine, you need to rethink it. Your project WILL cost 20% more than you think. Things will break and need to be replaced. I never changed my plan on my RV-10 from day one and I went over 23%. It just happens, ask anyone.

Tim Olsen's wife had a good right up about flying and the expenses.
http://www.myrv10.com/N104CD/why/wifesperspective.html

You have to choose to fly and give up lots of other things. What you give up the most is time. The maintenance on an RV-10 is high especially the first year while you are fixing issues and troubleshooting avionics. In the past six months I have had to fix the following issues or do the following maintenance:
- 5 oil changes
- Replaced dimming controller
- Repaired rear intercom wiring
- New wheel pant supports
- Replaced B&C alternator controller
- 2 new bulbs on wing tips
- Installed new GPS antenna for Cheltons
- Stiffened oil door - was slightly popping up
- Oil cooler duct flange broke - reinforced
- Remounted Grand Rapids Magnatometer
- Installed new elevator trim mounts - Solid Aluminum

All of that takes time which takes me to another point, the hanger. Another thing to consider is your working environment. It is nice not only for you but for your spouse if you have warm or cool (depending on the season) place to work on the plane. There are many Saturdays when my wife and I go up the hanger to be with each other and friends come by there to ride bikes and be together. If it wasn?t nice then we would be apart those times.

If you have money then don?t build, just go buy a Cirrus and pay someone else to maintain it. But for most of us we have to sacrifice many other things to afford our hobby. Also, build what Van?s says to build especially the engine. It is a proven design, it works great, and you can get it fixed anywhere.

I can promise you that after your first ride in an IO-540 RV-10 you will be all smiles.

 

[w1curtis]

I don't get it!

Scott,

Let me see if I can take a stab as this. The question was weather a 210 HP IO-3x0 engine would work in an RV-10. With various people offering opinions and unfounded justifications of one type or the other, the simple answer to the question is YES.

Before I continue, below is a picture of my engine which is bought and paid for. It is a 260 HP IO-540. As with all things, there is more to this simple answer. Contrary to what others have said here, Van?s did NOT design the RV-10 ONLY for the IO-540. It was engineered for engines from 210 to 260 HP. I find this reasonable because I currently fly a 2800 pound gross Cessna 177RG with a 200 HP engine and while at gross on a hot day it requires some extra piloting care, it is a safe, reasonable fast and very efficient cross country aircraft. Van?s however currently choose to only market the 260 HP IO-540 version of the kit. I can understand this because they are in business and as such seek to give people what they want. But let?s not confuse marketing as engineering.

Horsepower = Safety

I beg to differ!

Too often I find that builders (and pilots) mask poor piloting with increased horsepower as if the increased horsepower will make them more efficient and safer pilots. I don?t see this in the safety record of Cirrus SR-22 verses the SR-20? even when you take into account accidents as a percentage of the relative fleets. Don?t get me wrong, more power is nice, but let?s not try to convince ourselves and others that it will make ALL things better-be more efficient; more safer, etc. This is at best self delusion, at worst disingenuous.

First, one poster would have us all believe that a bigger engine would be more efficient.
If we extrapolate this argument; ---since the IO-540 would actually burn ** LESS ** fuel than and IO-390, let?s stick an IO-720 in there and since we can climb faster to altitude and cruise faster, we would actually get there quicker and thus burn less fuel?OoooKaay?we may have solved the fuel crisis here?bigger engines all around!

The more horsepower you have the safer you will be when you need to go around, or takeoff on a hot day, or the need to climb above some rain or a storm.

Now you say the bigger engine will make you safer?hmm. Take note ASF, we may have solved the problem of GA safety?bigger engines all around!

Weather you are going around because there is something on the runway, or you are going around because your high tension lawn dart is going too fast, the difference between 210 and 260 HP should not make much of a difference on climb out to a competent pilot. Rain by itself is usually not a safety problem but if you are trying to out climb a storm in a piston single then the additional horsepower we need is not under the cowling, but between the pilot?s ears.

If Van?s or someone wanted to put the time, effort and resources into a IO-3x0 firewall forward kit for the RV-10, I think it would be a FINE, SAFE flying aircraft. It would be totally within the Van?s design parameters of the RV-10, sacrificing some speed for increased efficiency. The fact is however, no such kit is available but we should not pull out our own --valid or invalid justifications- to discourage those who may choose to persue that path.

 

[rvbuilder2002]

Scott,

Contrary to what others have said here, Van?s did NOT design the RV-10 ONLY for the IO-540. It was engineered for engines from 210 to 260 HP.

Curtis,
Seems like we have gone over this before ....

Your statement above is true, but in a very generalized sense.

The proper statement would be "the RV-10 was designed for engines between 210 and 260 HP with a weight similar to the 6 cyl Lycoming."

I know personally that the airplane from the beginning was not designed with the use of a 4 cyl engine in mind. I am sure you are aware that designing an airplane is one big juggling act of compromises. Designing the RV-10 for engines with as wide a weight range as would be required by a Lyc O-360 to an IO-540 would have been a large compromise in the design.

I am well aware that some airplanes have evolved to much larger engines over time and have apparently been successful, but it is doubtful that they were designed with that in mind from the start. No designer that is striving to obtain max. performance from the start would make that compromise.

Nice looking engine by the way...

 

[w1curtis]

The proper statement would be "the RV-10 was designed for engines between 210 and 260 HP with a weight similar to the 6 cyl Lycoming."

OK, fair enough, let's examine the validity of that statement.
The Continental IO-360 ES used in N220RV weighs 305 pounds;
The 210 HP angle valve IO-360/390 weighs 308 pounds;
The parallel valve IO-540 weighs 410 pounds;

Your statement confirms that an IO-360/390 would work nicely in an RV-10. N220RV seems to fly OK, is safe and is not routinely falling out of the sky. I don't think anyone is getting 210 HP reliable out of a parallel valve O-360 I think you eluded to.

I know personally that the airplane from the beginning was not designed with the use of a 4 cyl engine in mind.

Can you share some of this personal knowledge? From the weight statement above were you also aware of the weight of the IO-360 in N220RV? What are your thoughts about the installation of a six cylinder Subaru in an RV-10? Is the experimental RV-10 designed for this?

 

[L.Adamson]

I beg to differ!

Too often I find that builders (and pilots) mask poor piloting with increased horsepower as if the increased horsepower will make them more efficient and safer pilots. I don?t see this in the safety record of Cirrus SR-22 verses the SR-20? even when you take into account accidents as a percentage of the relative fleets. Don?t get me wrong, more power is nice, but let?s not try to convince ourselves and others that it will make ALL things better-be more efficient; more safer, etc. This is at best self delusion, at worst disingenuous.

Nope.....

Must go along with Scott on this one! Considering density altitude out here in the mountain west; horsepower DOES provide a safety margin; and we have the accident statistics to prove it!

Sure, you can plan your "piloting" to fit the confines of a somewhat "lesser" powered engine, or know up front, that the bigger beast isn't going to have the limitations to start with.

Your choice, but certainly not an attempt to mask poor piloting. An example of poor piloting would be an attempted takeoff in less than desireable high density altitude conditions. Happens in the back country strips all the time. You might stay on the ground during heat of a summer day, or just have the available horsepower, to where it isn't a problem.

For these higher altitude mountainous areas, I'll take the max horsepower-----anyday!

L.Adamson

 

[L.Adamson]

Scott,

Weather you are going around because there is something on the runway, or you are going around because your high tension lawn dart is going too fast, the difference between 210 and 260 HP should not make much of a difference on climb out to a competent pilot.

And again, I beg to differ, as gutless is still gutless, competent pilot or not. We'll take the airport that Scott flies out of for instance. 4232' elevation, and surrounded by Class B airspace. Your choice is to do 360's , or straddle back and forth along the foothills of rising 10-12000' terrain, or simply have extra horsepower to climb right over it. That 200HP Cessna 177RG would be doing lot's of straddling!

Out here, even back in my student pilot day's, it was easy to see than 180HP had quite the advantage over 160HP. It was a no brainer to switch from the Warrior to the Archer. Same applies between 210 and 260, and has nothing to do with competence. Just density altitude!

L.Adamson

 

[az_gila]

England

Nope.....

Must go along with Scott on this one! Considering density altitude out here in the mountain west; horsepower DOES provide a safety margin; and we have the accident statistics to prove it!

.......

For these higher altitude mountainous areas, I'll take the max horsepower-----anyday!

L.Adamson

Yes... but the original (#1) post in this thread was from a builder in England.

The highest mountain in England and Wales is 3,600 ft and that in Scotland 5,000 ft (not exact figures, but close enough)

I'm sure that even with Global Warming a temperature of 90+ F has never been recorded on the top of Mt. Snowden (the Welsh 3,600 ft mountain)

I would believe the original poster has other concerns than high DA...

gil in Tucson - at 5000 ft DA when it's 81F...

PS the many times I hiked up Snowden as a kid, it was always cold and blowing like %^&$.... we couldn't afford the train up....

 

[L.Adamson]

Rain by itself is usually not a safety problem but if you are trying to out climb a storm in a piston single then the additional horsepower we need is not under the cowling, but between the pilot?s ears.
/QUOTE]

Okay, once again I'm irked, and it's getting past bed time!

Out here, storms may vary from those back east. Our storms may be contained between mountain ridges. While pure he## on one side, it may be pleasant on the other. XM weather can usually provide a good picture of what is what!

Let's go back to the "Jessica Dubroff" crash. The story of a seven year old "supposeable" pilot, attempting to make a cross country flight.

Takeoff is from a high density altitude airport in Cheyenne, Wyoming (6156') using a Cessna 177RG, with a fast approaching rain storm and crosswinds.

The pilot (actually the instructor) must fly directly into the direction of the storm , then make a near 180 course reversal. Due to a "slow" climb rate and wind conditions, the aircraft stalled in the turn, and fell onto a residence driveway.

While the Cessna might be saying, "I think I can, I think I can" while plugging slowly along..................it would have been a non-event in a "higher" powered RV-10, 9, 7, 6, 4 or 3.

In the RV, you'd simply see the storm clouds from the northwest, clear sky's to the east, and climb right out of there before any problem occurs. But, with the "underpowered" Cessna, it certainly WAS a fatal pilot decision. Once again, horsepower can easily change the outcome...

Out here in the mountains, horsepower = airspeed and climb rate, which = added safety margins! Argue all you want, and I'll still disagree!

L.Adamson

 

[L.Adamson]

Yes... but the original (#1) post in this thread was from a builder in England.

I admit, that I never got back to page one and the original post... Started from the end.

However, over the years, I've gotten into a few disagreements with several UK pilots regarding "the leaning" process. They just don't believe it's important before takeoff, until they actually fly out of here!

 

[w1curtis]

Let's go back to the "Jessica Dubroff" crash. The story of a seven year old "supposeable" pilot, attempting to make a cross country flight.

Takeoff is from a high density altitude airport in Cheyenne, Wyoming (6156') using a Cessna 177RG, with a fast approaching rain storm and crosswinds.
..
..
L.Adamson

OK, let's correct this. The Jessica Dubroff incident was in a 160 HP FIXED gear Cardinal with a clearly underpowered 160HP engine-not the fixed gear "A" model with 180HP or the 177RG with a 200HP engine. A competent pilot would have chosen not to take off or to turn in the face of rising terrain. Maybe horsepower would have helped here, but a proficient Jessica was not--even more proof that HP between the ears is more important than HP under the cowl.

 

[az_gila]

DAs..

I admit, that I never got back to page one and the original post... Started from the end.

However, over the years, I've gotten into a few disagreements with several UK pilots regarding "the leaning" process. They just don't believe it's important before takeoff, until they actually fly out of here!

That's why I know our home airpark is 5000 DA at 81F.... just like Lycoming says to lean for takeoff...

High DAs do make a difference!!

gil in Tucson ... left England 37 years ago...

 

[rvbuilder2002]

OK, fair enough, let's examine the validity of that statement.
The Continental IO-360 ES used in N220RV weighs 305 pounds;
The 210 HP angle valve IO-360/390 weighs 308 pounds;
The parallel valve IO-540 weighs 410 pounds;

Your statement confirms that an IO-360/390 would work nicely in an RV-10. N220RV seems to fly OK, is safe and is not routinely falling out of the sky. I don't think anyone is getting 210 HP reliable out of a parallel valve O-360 I think you eluded to.

Can you share some of this personal knowledge? From the weight statement above were you also aware of the weight of the IO-360 in N220RV? What are your thoughts about the installation of a six cylinder Subaru in an RV-10? Is the experimental RV-10 designed for this?

Curtis,

I do have personal knowledge about N220RV. I built most of it.

The IO-360ES is heavier than 305 lbs. The spec you linked to is for "basic engine dry weight". Often this means the quoted weight is minus accessories such as starter, alternator, etc. It is very common for weights to be spec'ed this way. This weight looks better on paper, and they don't know what specific accessories will be used in a particular installation. Another factor is that the installed weight is heavier than a 4 cyl engine would be, because of a bed style engine mount, heavier exhaust system, etc.

I stand by my original statement...
An RV-10 built with a 4 cyl engine would be sacrificing utility because of C.G. issues (I am not even going to join the safety argument).
Would it fly? Sure! But it would be a compromise outside of the original design parameters. (BTW I never said a 4 cyl engine in an RV-10 would make it "routinely fall out of the sky".)

The only thing I was responding to you about specifically, was that you implied personal knowledge that the RV-10 was designed for any engine between 210 and 260 HP. I was simply pointing out that, that statement is not true.

 

[gasman]

Scott, go to bed..... remember, you are on PDT......

 

[rvbuilder2002]

Scott, go to bed..... remember, you are on PDT......

I know...Kind of late.
I was up late painting some parts and needing to wind down first...

 

[w1curtis]

Truthiness

OK, the horse is dead so this will be my last post on this thread.

Must go along with Scott on this one! Considering density altitude out here in the mountain west; horsepower DOES provide a safety margin; and we have the accident statistics to prove it!

Can you share these accident statistics? Here are some statistics I pulled from the NTSB page. Go there and check for yourself.

For the period 2002-2007
Model-SR-20, Registered-642, Accidents-7, Fatal Accidents-2, Fatalities-3
Model-SR-22, Registered-2243, Accidents-19, Fatal Accidents-8, Fatalities-15

Accident rate is about the same for both. Show me your data where increased "horsepower DOES provide a safety margin?"

Every time questions like this come up, what irks me is the level of Truthiness that is spued forth by armchair experts. While I have made my choice in engines, I don't try to convince anyone that it is the best and only choice for them. Just as I would try to convince everyone that my choice of instrumentation is the best and only choice for them.

Out here in the mountains, horsepower = airspeed and climb rate, which = added safety margins! Argue all you want, and I'll still disagree!

I don't view this as an argument. You and others are making statements without the data to back it up. I'm providing data to show that those statements are incorrect. To me an argument is when parties toss opinions back and forth without any data on either side to back it up.

The only thing I was responding to you about specifically, was that you implied personal knowledge that the RV-10 was designed for any engine between 210 and 260 HP. I was simply pointing out that, that statement is not true.

Now you are attributing statements to me which I did not make. Where did I imply "personal knowledge?" On the Van's website and in the RVAtor articles, Vans's has performance specifications for engines from 210 to 260 HP. This does not require any "personal" knowledge, only the ability to read. You on the other hand, working in the Van's prototype shop state specifically that you have "personal knowledge" that the RV-10 is ONLY designed for a six cylinder engine. However it seems you were not aware of the weight of the Continental IO-360 engine. All the weights that I listed, for both the Continental and the Lycoming represent "dry" weights and represent an "apples to apples" comparison. The difference in weight of the engine mounts and exhaust is not going to add 100 pounds to the Continental IO-360 firewall forward installation.

 

[L.Adamson]

OK, the horse is dead so this will be my last post on this thread.

Can you share these accident statistics? Here are some statistics I pulled from the NTSB page. Go there and check for yourself.

For the period 2002-2007
Model-SR-20, Registered-642, Accidents-7, Fatal Accidents-2, Fatalities-3
Model-SR-22, Registered-2243, Accidents-19, Fatal Accidents-8, Fatalities-15

Accident rate is about the same for both. Show me your data where increased "horsepower DOES provide a safety margin?"

Am I suppose to go through every Cirrus accident, looking for performance differences, and if performace/climbing ability had anything to do with the accident?

How about just doing a search for "density altitude". You'll get an immediate 33 pages worth. Then try Vans & density altitude, or RV & density altitude. Nothing...

I suppose there might be something if you look hard enough; or perhaps performace due to weight and horsepower in Van's airplanes just seems to keep them out of the density altitude statistics!

Then pop over to websites such as those for the Aviat Husky. Here is a "single engine" plane built in Afton, Wyoming (6201' msl), where people really DO know about density altitude. In fact; it's horsepower, performance, and density altitude that all fit hand in hand, when you read Aviat's literature. Seems that as the horsepower increases, the performance rises, and density altitude worry's diminish. It's one of their strong selling points!

L.Adamson

 

[rvbuilder2002]

Now you are attributing statements to me which I did not make. Where did I imply "personal knowledge?" On the Van's website and in the RVAtor articles, Vans's has performance specifications for engines from 210 to 260 HP.
<pasted in from a previous post>
Contrary to what others have said here, Van?s did NOT design the RV-10 ONLY for the IO-540. It was engineered for engines from 210 to 260 HP.

The original post that I replied to seemed to imply that since Van designed the RV-10 for engines from 210 to 260 HP that you felt any engine that fell within this range then should be fine (such as an IO-3X0). I was just pointing out that the design was also for a specific weight range of engine. Not just any engine that met the HP requirements. The IO-360ES is within that weight range. An IO-390 would not be.

If that was not the intent of your statement, I misunderstood and I apologize.

 

[ScottSchmidt]

WOW!

There has been quite a bit of discussion the past 24 hours. Just got back from PHX. RaNae and I went to the Nascar race. I'll post report and pictures but had a great time.

All I can say is I sure enjoyed having the 540 under the cowl. We would pop up to 16,500 ft then back to 12,500 then back up to 15,500 with no problem. This plane is awesome.

I never meant to say anything negative, I just would like people to take a 2 hour flight in each plane and see if the horsepower fits their mission. Lets say there is no CG issue. If you are going to fly around the airport and never travel much then it should be great. But if you are going to be flying cross country, IFR (no ice of course), around mountains, you will want more power. Man I would love to 400 HP for climbing and the 260 for cruising. No more than 1.5 hours ago I was flying 200 miles south of Utah climbing over a localized storm and was able to drop into the valley near Richfeld. If I was in an Archer, I would be flying in the rain or I would have diverted to the east. There was no danger, I didn't want to go IFR because I would have had icing conditions up higher.

This is the same discussion I have with motorcycle riders (I know I have posted this other plases but here it comes again). I ride alot and people want to know what bike to get. I always say get the biggest one you feel comfortable with. Here is the response I always get,"I would never need more than 750 cc". That is fine, but if they keep riding, they always upgrade to something over 1000 cc. Sure the gas mileage isn't as good but again, if you are going to drive a bike cross country, you need more power to pass, have more weight for wind, and more element protection.

But I will stick by my statement Horsepower = Saftey. But I guess I should have added, "as long as it is used wisely", but didn't think I needed to say that. We all try and make the best descions possible.

Hope you all had a great flying weekend!

Here are some numbers to make you -10 builders happy! Salt Lake to Scottsdale AZ (499 miles). From wheels up to wheel down flying to Scottsdale was 2 hours 44 minutes. (182 mph average)
From wheels up to wheels down flying back to Salt Lake was 2 hours 39 minutes. (188 mph) Both flights include lots of climbing / decending / diverting for weather and pattern work for landing.

 

[TSwezey]

Man I would love to 400 HP for climbing and the 260 for cruising.

Hopefully, this is what I will have with my supercharged LS-2. The neat thing about the Vesta system is that you can shut down half the engine while running it. I have tried this on the ground and you can not tell (sound and smoothness wise) that only half the engine is running. Ideally I should be able to climb to altitude with the full engine and cut off half the engine for economy cruise. I know I won't be able to cruise at 180mph with half the engine but I should be able to burn a lot less fuel on four cylinders. I can have an 8 cyl and a 4 cyl.

 

[ScottSchmidt]

Hopefully, this is what I will have with my supercharged LS-2. The neat thing about the Vesta system is that you can shut down half the engine while running it. I have tried this on the ground and you can not tell (sound and smoothness wise) that only half the engine is running. Ideally I should be able to climb to altitude with the full engine and cut off half the engine for economy cruise. I know I won't be able to cruise at 180mph with half the engine but I should be able to burn a lot less fuel on four cylinders. I can have an 8 cyl and a 4 cyl.

Do you think you will make Oshkosh? Love to hear that RV-10.

 

[TSwezey]

Do you think you will make Oshkosh? Love to hear that RV-10.

I am very hopeful that I will be there.

 

[rattus]

...

This is the same discussion I have with motorcycle riders (I know I have posted this other plases but here it comes again). I ride alot and people want to know what bike to get. I always say get the biggest one you feel comfortable with. Here is the response I always get,"I would never need more than 750 cc". That is fine, but if they keep riding, they always upgrade to something over 1000 cc. Sure the gas mileage isn't as good but again, if you are going to drive a bike cross country, you need more power to pass, have more weight for wind, and more element protection.

Scott, let me start by saying I think yours looks like one of the finest RV-10s in existence, and this lurker always enjoys your writeups.

That said, as a rider of 37 years I have never, ever seen a more incorrect statement about motorcycle safety. The "get the biggest bike you feel comfortable with" attitude is probably more responsible for the rapidly escalating motorcycle death rate than any other factor. Been to far too many funerals for folks that fell for that one, whether they were the RUB cruiser type trying to wrestle an 800 lb. chrome-encrusted monstrosity or the basic squid on his brand new 180 hp GSXR1000 (but Matt Mladin rides one!).

All other factors being equal (experience, handling, brakes, safety gear, etc.) horsepower and weight kill on bikes. On many of the roads out here or on tighter tracks I will outbrake, outcorner, outhandle and generally outrun you (on the fastest bike on the planet), using a lowly (but oh-so-beautiful) Aprilia RS125, and be a heck of a lot safer for it too, since horsepower and weight are the only performance factors on a bike that decrease safety.

Sure, there are (few) situations where horsepower may come in handy, such as accelerating some barge up an onramp on the interstate but if you're riding the interstate, why bother with a bike? Extra weight doesn't help anywhere except in warding off hypothermia. Your operative word was "drive" - I suspect an audio system is part of your riding experience.

A bike isn't an airplane, although the laws of physics apply to both. On a bike smaller = lighter = more nimble = better braking = better handling = safer. Period. The only thing a bigger bike buys you is load capacity, but again, if that's a factor take the cage. You won't enjoy the ride anyway.

At 6540' MSL, I'll take a bit of extra power in the RV on takeoff, though. For me a turbo-normalized 4 cylinder might be a better solution. Might buy some range, better capacity, better economy, etc.

Mike (the hypocrite that rides a BMW (but a light one!) a lot of the time, but wishes they built the RS125 in extra-tall. ;-) )

 

[L.Adamson]

Scott, let me start by saying I think yours is one of the finest RV-10s in existence, and this lurker always enjoys your writeups.

That said, as a rider of 37 years I have never, ever seen a more incorrect statement about motorcycle safety. The "get the biggest bike you feel comfortable with" attitude is probably more responsible for the rapidly escalating motorcycle death rate than any other factor.

Got you beat! 42 years on motorcycles, and the last has been a Honda Valkyrie (1520 cc)which I bought new in 1998. Weighs about 750 ibs, with all the junk on it, but will easily turn a 180 on a two lane street with the wheel barely turning. Very well balanced!

It's very powerful, but the engines still get bigger, and it's been one of the best cornering large cruisers available.

Personally, since I've taken many long distance rides over the years, I prefer the "bigger" stuff!

If it wasn't for the expense of airplanes, I'd probably get a new Wing or BMW, along with a Harley Road King or Heritage Softtail for the national parks...

IMO, the funerals are for the speedsters who haven't yet learned how to stay in their lane, when things get out of hand.

L.Adamson

 

[L.Adamson]

A bike isn't an airplane, although the laws of physics apply to both. On a bike smaller = lighter = more nimble = better braking = better handling = safer. Period. The only thing a bigger bike buys you is load capacity, but again, if that's a factor take the cage. You won't enjoy the ride anyway.

Just one more time,

I read this reply about five times now, and you can't be serious, can you? I've been all over the mountain west on cycles from Denver to California, the top of Idaho to near Mexico, and can't imagine doing it on what equates to a "dirt bike" just to be light!

L.Adamson -- a fan of the old Route 66

 

[rattus]

From the standpoint of safety (that was the subject, was it not?) on a motorcycle, power and weight are your enemy.

That's what I should have said and dispensed with the editorial filler. ;-)

Mike

 

[ScottSchmidt]

I never said more powerful motorcycles are safer, just more comfortable. It was the airplane that I felt was safer with more power.

But again, you have to be smart with horsepower. You and I are probably not the ones to worry about in the air or on the ground.

So are you saying Boeing should decrease the horsepower in all their planes to increase safety? That arguement just doesn't make sense. You always have to take ideas to the extreme to check them for validity.

OK, forget the safety issue, obviously I'm not going to convince you of that. The real reason you want more power is plain old fun! Horsepower is fun. It is fun to take off in 500 feet and climb out at 2000 ft/min, and fun to drag race your buddies. It is fun to run 128 mph at the Salt Flats. Ask a new Epic owner how they like their 1200 hp planes.
Glad you are at least dreaming the dream. It's better to have a motorcycle than no motorcycle at all. The same goes for planes.

Peace Out!

 

[rattus]

...and from the standpoint of fun, I couldn't possibly disagree with you!

Mike

 

[Pick]

At the risk of muddying the water some more........an O-540 is typically going to be turning a larger, more efficient prop, so at a given fuel burn it will typically be going faster than an otherwise identical airframe with an O-360.......or at a given true airspeed it will be burning less fuel. You have to think in terms of torque and propeller efficiency in order for it to make any sense. (plus you have the benefit of the extra power when you need/want it)

The best real-world example I can think of right off hand is to look at Bob Barrows' first two Bearhawk prototypes.......the first had an O-360, the second has an O-540. The numbers are really pretty surprising.

http://www.airbum.com/pireps/PirepBearhawk180.html
http://www.airbum.com/pireps/PirepBearhawk260.html

All of that being said, I'm thinkin' that a "midsized" RV in a 2+2 type configuration would be about perfect.

I'll go back to lurking now.

 

[Phyrcooler]

All of that being said, I'm thinkin' that a "midsized" RV in a 2+2 type configuration would be about perfect.

I'll go back to lurking now.

The "Stretch-9" I've been asking for!! Share your comments with Van's. Maybe if I'm lucky a kit will be ready when I am in a few years (after I build a -12).

 

[ScottSchmidt]

The "Stretch-9" I've been asking for!! Share your comments with Van's. Maybe if I'm lucky a kit will be ready when I am in a few years (after I build a -12).

That would be a nice plane. Typically it is just my wife and I flying and it is so nice to reach between the seats and open a cooler. Plus, we can carry more bulky things if no one is in the back.

I'm sure Van is very nervous about that because he likes to keep his planes sporty with good control harmony. That is his brand. When you start stretching planes, it does make the plane fly quite different depending on the CG.

I know there is someone out there that built an RV-6 with backward facing seats. Seems like he stretched it about 1 foot. Anyone have a picture of that one?