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flydoc

Active Member
Okay, this will show my ignorance :eek: , but I was comparing the RV-10 with the Lancair ES. If you hang a Cont. IO-550 310 hp in front of an ES, you get a reported cruise speed of 225mph. With the IO-360, you get 200mph. I couldn't help but notice that the lesser hp engine gives the same reported speed as a -10 with the IO-540 260hp. I was wondering if the airframe of the -10 will support the larger engine, or if this would even be a prudent consideration?

Mark

P.S. I apologize to EVERYONE for bringing up the "L" word :eek: on the Vans forum.
 
Perfrormance comparisons

flydoc said:
If you hang a Cont. IO-550 310 hp in front of an ES, you get a reported cruise speed of 225mph. With the IO-360, you get 200mph. I couldn't help but notice that the lesser hp engine gives the same reported speed as a -10 with the IO-540 260hp.
Click to expand...
Mark,

I don't understand your comparison.
-The 260HP RV-10 has a 75% cruise of 201 and a top speed of 211.
-The 210HP RV-10 has a 75% cruise of 190 and a top speed of 200.
The 225 and the 200 that you report for the Lancair, are these cruise or top speeds? I'm guessing these are top speeds.

The 310HP IO-550 is too heavy for the RV-10. What is the L-word that you are referring to?

http://www.vansaircraft.com/public/rv-10per.htm
 
w1curtis said:
-The 260HP RV-10 has a 75% cruise of 201 and a top speed of 211.
-The 210HP RV-10 has a 75% cruise of 190 and a top speed of 200.
The 225 and the 200 that you report for the Lancair, are these cruise or top speeds? I'm guessing these are top speeds.

The 310HP IO-550 is too heavy for the RV-10. What is the L-word that you are referring to?

http://www.vansaircraft.com/public/rv-10per.htm
Click to expand...

William,

The reported 225mph with the ES is the cruise speed with the larger engine. I was just wondering if the -10 would accept an I0-550.

Mark

The "L" word is Lancair. :)
 
Bigger not necessarily better

Mark: There's a major article in a recent RViator which considers in great detail engine choices for the RV-10. For the many reasons explained in the article Van's feels the 260 hp IO-540 is the largest engine you should use - it's a great article and well thought-out, like everyting Van does. Bill
 
Power is an expensive way to buy speed

If you were to install a 300 HP engine in an RV-10, and did not change the weight, prop efficiency, or drag at all, you'd only increase the speed maybe 10 mph compared to a 260 HP model

Speed goes with the cube root of power, so every 1% increase in speed costs you about 3% more power. Notice that the difference Van's lists on their Web site between the 210 HP model and the 260 HP model is only 11 mph.

Lancairs go faster because they have less drag, primarily. Little wings, smooth surfaces, low wetted area, retractable landing gear.

It would have a bigger effect on rate of climb, though. Again comparing the 210 HP vs 260 HP numbers, with a 300 HP engine (and again assuming no difference in weight, prop efficiency, or drag) you'd see the ROC go from 1450 ft/min to about 1700 ft/min.

Regards,
Martin
 
Differnce RV-10 vs. Lancair ES

The big differnce is $46,000 :eek:

....................................RV-10........Lancair ES
Horse Power.....................260 HP............310 HP
Cruise [75% @ 8000 ft]......201 mph..........225 mph
Stall Speed........................57 mph............65 mph
Takeoff Distance.................360 ft............600 ft
Landing Distance.................525 ft............800 ft
Rate of Climb...................1,950 fpm.......2,000 fpm
Ceiling (est.)..................24,000 ft.........18,000 ft
Empty Weight..................1,520 lbs.........1,900 lbs
Gross Weight...................2,700 lbs.........3,200 lbs
Max useful......................1,180 lbs..........1,300 lbs
Fuel...................................60 Gal.............95 Gal
KIT COST.............$34,910/($44,860 QB)....$75,500

If the RV-10 had a 310 HP engine it would cruise approx 6% faster:
201 mph x (310/260)^(.33) = 213 mph,
so the Lancair claimed cruise is 12 mph faster.

I think if you want to cruise faster, consider a Turbo charger (normalizing). Both nice planes, but the kit price difference, cost of larger engine would make my 4 place kit plane choice easy. Goooooooo Team Van's.
Cheers George RV-7
 
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gmcjetpilot said:
The big differnce is $46,000 :eek:

....................................RV-10........Lancair ES
Horse Power......................260 HP..........310 HP
Cruise [75% @ 8000 ft].......201 mph........225 mph
Stall Speed.........................57 mph...........65 mph
Takeoff Distance.................360 ft..............600 ft
Landing Distance.................525 ft..............800 ft
Rate of Climb...................1,950 fpm.........2,000 fpm
Ceiling (est.)..................24,000 ft..........18,000 ft
Empty Weight..................1,520 lbs...........1,900 lbs
Gross Weight...................2,700 lbs...........3,200 lbs
Max useful......................1,180 lbs...........1,300 lbs
Fuel...................................60 Gal...............95 Gal
KIT COST.............$34,910/($44,860 QB).......$75,500
Click to expand...


Well, if you put it THAT way! Thanks for clearing that up.

In another life, I owned a C-182 that had a Horton speed kit with flap gap seals, etc. Do any of you know of any speed kits available for the RV series? I realize that given the airspeed of the basic frame, rivets and all, that the airframe is probably as clean as it can get!

Thanks,
Mark
 
The big differnce is approach speed :eek:

gmcjetpilot said:
....................................RV-10........Lancair ES
Stall Speed.........................57 mph...........65 mph
Takeoff Distance.................360 ft..............600 ft
Landing Distance.................525 ft..............800 ft
Click to expand...

Based on an ideal (theoretical?) approach spead that is 1.3 times the stall spead we come up with:

....................................RV-10........Lancair ES
Approach Speed.................75 mph...........85 mph

That is a lot of energy to dissipate if you ever have an off airport landing, not to mention the longer landing distance.

Both are good aircraft but I think I would rather have the extra seats and lower approach speeds.

Just my $.02 worth.
 
flydoc said:
Well, if you put it THAT way! Thanks for clearing that up.

In another life, I owned a C-182 that had a Horton speed kit with flap gap seals, etc. Do any of you know of any speed kits available for the RV series? I realize that given the airspeed of the basic frame, rivets and all, that the airframe is probably as clean as it can get!

Thanks,
Mark
Click to expand...

Check out this old thread: http://www.vansairforce.com/community/showthread.php?t=543

Blue Skies,
 
Rivets vs drag vs BIG engine

I wanted to respond to Mark/Flydoc,
The rivets in exposed areas of the RV series are all flush mounted so they contribute little to drag or at least parasitic drag. Fuselage to flying surfaces however are much more draggy on an RV than the Lancair series. Much improvement could be made on the RV-10 with intersection fairings and other cleanup items. The Lancair ES is also a fixed gear aircraft so most of it's improvement in speed is based on a small cross sectional area and smooth well faired surfaces. Lets face it it's prettier than a RV-10! But, is it 3 times prettier? I don't think so. Thats why even though I'm skilled in composite construction that I chose an RV-10. (Not to mention insurance, resale, utility, BLA, BLA, BLA)
The fact is that Van even lamented that as soon as he published the IO 540 as the engine of choice he had calls about fitting a larger one. Don't bother it really isn't worth it, especially if you consider the fuel burn costs for those few knots!
Bill Jepson
Rotary10-RV
 
Actually the wing root to fuselage intersection on RVs is quite efficient. This angle only gets draggy if it is more acute than 90 degrees of if the fuselage taper starts ahead of the trailing edge. Several people have tried nice flowing intersection fairings to no avail. On the Lancairs the fuselage taper starts further forward thereby needing the large fairings. If you can get a copy of the video of the little fixed gear airplane "Why It Goes So Fast" that does 213 mph on 65hp, he explains it very clearly.
Mel...DAR
 
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RV-10 vs ES drag

Rotary10-RV said:
The Lancair ES is also a fixed gear aircraft so most of it's improvement in speed is based on a small cross sectional area and smooth well faired surfaces.
Click to expand...

To expand on that, if I had to guess, I'd say the difference in drag between the ES and the RV-10 boils down to 3 factors:

1) Less wetted area. The ES has a smaller wing (140 ft^2 vs 148 ft^2) than the RV. This is the main reason why Lancairs and Glasairs go so fast. If you put wings that small on a Cherokee, it would cruise (and land) faster too. Unless you get up to high altitudes (low indicated airspeeds), the majority of the drag in cruise will come from skin friction rather than induced drag. The rounder cross section of the fuselage also helps to reduce wetted area.

2) Slightly increased laminar flow. Composites do get slightly better laminar flow and reduced boundary layer thickness compared to a riveted structure, both on the fuselage and the wings. This will reduce friction drag.

3) Better fairings, gap seals, etc. Composite construction allows for smoother transitions, reducing the ability of these locations to trip the boundary layer or cause local flow separation.
 
RViator

Bill Dicus said:
Mark: There's a major article in a recent RViator which considers in great detail engine choices for the RV-10. For the many reasons explained in the article Van's feels the 260 hp IO-540 is the largest engine you should use - it's a great article and well thought-out, like everyting Van does. Bill
Click to expand...


Do you know which issue this is in? I would like to back order it.
 
RV-10 Power

It's in the sixth issue, 2004. In the interest of drag, we had a 1966 Commanche 260B which we flew over 2000 hours. What a great 'plane. The airfoil was a laminar flow modern design that was supposedly very sensitive to any surface disturbance. My partner (and his wife) were flying to Lake of the Ozarks years ago from Milwaukee. Fzg lvl was about 8000. Past ORD they were climbed up - and up. Finally at 20,000, on oxygen, they hit really bad CB and hail. Wife said later "didn't you see that giant black cloud?" - no, because his half of the windshield was iced over. By description, it was wild. Oxygen bottle and heads hitting the ceiling, windshield cracking, impossible to talk (even shouting lips to ear) and then engine quitting due to hail packing the intake. They got engine started at 12,000 and made precautionary ldg. Hail had made shallow (very) depressions around the cowl (engine intake) about 3 to 4" across. Also the leading edges were hammered throughout - some of the shape retained inboard where skin is thick, almost totally flat outboard. Everyone thought the airplane was grounded. Despite all that laminar flow stuff it flew, took off, stalled, climbed and cruised exactly as it had for 2000+ hours before. We ( knowing this) flew it to Jackson Hole where people came out of the woodwork shaking their heads and commiserating. Always made me wonder about laminar flow. The 260B had a service clg over 20000 feet and this was March, with light weight. It probably still climbed four or five hundred feet/min @ 20,000. Bill
 
Fly Doc....

Do you currently have a project going yet? I noticed you are in Arlington? Me too. 40-years worth! :D

I am over off of Fielder and Park Row, north of the UTA football stadium. Where are you located?
 
Rv-10

Sorry - my answer to TKJaviator (?) was incomplete. The first article was in second issue 2004 on page 10, titled "The Right Power." Second one was by Ken Krueger and is on p 3 of sixth issue 2004, "Flying High and Fast." Educated me that VNE related to TAS, not Q or IAS. Bill
 
I'd Have to agree with GMC here, want a few more knots, best to turbo it and go higher with ox. Should be able to get 190 knots TAS at 18,000.

Ross

Flying RV6A Turbo Sube
Building RV10 Turbo Sube
 
speed

The bottom line is, if you want to go that much faster, buy a faster (Lancair)
airplane. My friends have pushed the RV6 envelope about as far as possible, 230 mph max, in the S&F 100 race and I don't see what it really gains. Anywhere in Florida we go, I am no more than 5 minutes behind when we arrive and I am flying a draggy 6A that only cruises at about 160 mph. But I get there on 6-7GPH as opposed to 12-14. Think about it.
Roger
 
125 kts RV10 ??!!!

Randy posted that at 10.5 gph he got 125 kts for his RV10
I hope it was a typo (should it be 152 kts ?) because otherwise the RV10 is even slower than a C 182 at lower power settings !!!!!!!!!
 
Just got back from ARL in a C-182.

Those Lancairs and Glassairs and Cirrus' kept making non-stop 200kt. circuits around the field and then pulling up, banking and looking like P-51's. Sure wished a RV would have made a few passes.

The black jacks and the Dueling Rocketeers were crowd pleasers though. The Black Jacks sounded like bombers, all seventeen of them-- probably the highlights of the weekend.
 
300 hours on my RV10. I have a Barrett 540-X rated at 290 hp. I cruise at 170 kt TAS at 10,000 at 21” MP and 2,300 rpm with a fuel flow of 10.5 gal/hr. That works out to just over 16 nm/gal. The ES is a totally different aircraft. It would be more appropriate to compare a Cirrus to a RV10. My RV10 can land almost anywhere.
 
gmcjetpilot said:
The big differnce is $46,000 :eek:

....................................RV-10........Lancair ES
Horse Power.....................260 HP............310 HP
Cruise [75% @ 8000 ft]......201 mph..........225 mph
Stall Speed........................57 mph............65 mph
Takeoff Distance.................360 ft............600 ft
Landing Distance.................525 ft............800 ft
Rate of Climb...................1,950 fpm.......2,000 fpm
Ceiling (est.)..................24,000 ft.........18,000 ft
Empty Weight..................1,520 lbs.........1,900 lbs
Gross Weight...................2,700 lbs.........3,200 lbs
Max useful......................1,180 lbs..........1,300 lbs
Fuel...................................60 Gal.............95 Gal
KIT COST.............$34,910/($44,860 QB)....$75,500

If the RV-10 had a 310 HP engine it would cruise approx 6% faster:
201 mph x (310/260)^(.33) = 213 mph,
so the Lancair claimed cruise is 12 mph faster.

I think if you want to cruise faster, consider a Turbo charger (normalizing). Both nice planes, but the kit price difference, cost of larger engine would make my 4 place kit plane choice easy. Goooooooo Team Van's.
Cheers George RV-7
Click to expand...

I read a paper Van’s wrote about turbocharging a RV10. It was obvious you would run out of flutter margin quite quickly if you turbocharged a 10. It’s not a good idea. More hp is fine if you don’t add any weight. I have a Barrett 540-X rated at 290 hp. The extra climb performance is really welcome at high DA airports. I cruise at 170 kt TAS on 10.5 gal/hr. Top speed is 190 TAS which is crowding the 200 kt TAS limit.
 
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