Mooney 231 vs Rv-10 at 16k

[willerjim273]

I have a really nice 1980 231. My mission is out of Denver and 16k in 30 miles. She does the job well. However, the avionics bug has me. And the exp world is awash. 

 

I am looking for data on how a 10 compares. Here is my basic logic. Using 16k as standard, the 260 Lyc will be at about 15.4" or about 62% power which equates to about 161 HP. We can say the Mooney is still putting out 200 HP. But is it? Most likely we will be LOP and at a lower actual HP. I have a new (rebuilt) Skyways engine and just changed from mineral oil. I am a coward to try LOP because I cannot find anyone in Denver  to be in cockpit with me who knows what they are doing. So I am burning about 13 GPH at 28" and life is good. I am seeing about 160-170 TAS. Anyone have an efis that will tell you what % HP you are when LOP at 16k??

 

After that we have to look at drag etc then compare all sorts of things that get real tricky. The MP comes from this thread..  http://www.vansairforce.com/community/showthread.php?t=88214

 

thoughts, Ideas?

[Bryan]

@gsxrpilot just moved to that area and flies a M20K LOP a lot.  I bet he would go up with you to explore LOP operations in your 231.  He has a great panel for displaying TAS along with FF and MAP settings. My previous bird (231) did LOP great. 

Can (somone) say the Mooney is still putting out 200HP at 16000, yes, at full power setting.  The critical altitude for this is much higher and you will not be losing MAP at 16000 under normal circumstances.  However, pulling the MAP back, RPM back, and FF back, you will be crusing at less than 200HP. 

[jaylw314]

Design-wise, the RV-10 is a slippery airframe, with flush riveting everywhere.  Pain in the ass to build, but slippery.  The difference is that the wing is more of a Hershey-bar cross section, so it is somewhat more efficient at higher angles of attack than at higher speeds.

Or you could wait for the Deltahawk diesel motor like I am.  If it ever materializes, you'd have a 200 hp altitude motor that you could run at 100% all the way up to 25k.

Edited July 9, 2019 by jaylw314

[carusoam]

Jim,

Are you buying or building?

Building takes a long time...

So Keep flying the K... 

The last K owner to complete a Lanceair project, only took about two decades to complete.

 

Keep flying the K... but do some studying on its engine ops... there is plenty to learn.  Plenty to get out of it.  Plenty of guidance around here...

Got an engine monitor?

There are probably 10 individual steps to improve engine ops for every plane... from starting to shut-down... the LOP is icing on the cake for the K’s Continental...

Some of the best MS threads are discussions on K ops...

Best regards,

-a-

[aviatoreb]

7 minutes ago, carusoam said:

The last K owner to complete a Lanceair project, only took about two decades to complete.

 

...but it turned out pretty nice.

[carusoam]

Perfection is a general requirement of most Mooney Pilots... 

Perfection takes time and effort...

 

If a perfect project takes 20years...

The Sooner we start, the Sooner we can complete...

 

i can’t seem to find the Lanceair starter kit...

Would you buy the engine kit today, or wait til year 19?

 

Best regards,

-a-

[KLRDMD]

1 hour ago, willerjim273 said:

I am burning about 13 GPH at 28" and life is good. I am seeing about 160-170 TAS. Anyone have an efis that will tell you what % HP you are when LOP at 16k??

65% power LOP in that engine is exactly 10.0 GPH, spread sheet attached. No other value matters other than fuel flow when calculating LOP %.

I don't recommend running a TSIO-360 series at greater than 65% power in cruise, LOP or ROP. But if you don't mind buying a set of cylinders, or two, feel free to fly at 75% or greater with this engine.

LOPFFvsHP calculator.xls

Edited July 9, 2019 by KLRDMD

[Niko182]

1 hour ago, willerjim273 said:

I have a really nice 1980 231. My mission is out of Denver and 16k in 30 miles. She does the job well. However, the avionics bug has me. And the exp world is awash. 

 

I am looking for data on how a 10 compares. Here is my basic logic. Using 16k as standard, the 260 Lyc will be at about 15.4" or about 62% power which equates to about 161 HP. We can say the Mooney is still putting out 200 HP. But is it? Most likely we will be LOP and at a lower actual HP. I have a new (rebuilt) Skyways engine and just changed from mineral oil. I am a coward to try LOP because I cannot find anyone in Denver  to be in cockpit with me who knows what they are doing. So I am burning about 13 GPH at 28" and life is good. I am seeing about 160-170 TAS. Anyone have an efis that will tell you what % HP you are when LOP at 16k??

 

After that we have to look at drag etc then compare all sorts of things that get real tricky. The MP comes from this thread..  http://www.vansairforce.com/community/showthread.php?t=88214

 

thoughts, Ideas?

There places that a turbo is a nice addition and a turbo is required. If you normally fly out of airports at 5 to 10k ft with density altitudes up to 13k, a non turbo charged is not really an option. Would i take my NA aspirated aircraft to Colorado? yes. would I live there with an NA aircraft? no. Unless you find a RV10 with a Turbo on it, I wouldn't even consider an RV10 for your mission.

[KLRDMD]

1 hour ago, willerjim273 said:

I am burning about 13 GPH at 28" and life is good. I am seeing about 160-170 TAS.

For what it is worth, I ran my 231 at 30", 2500 and 9.0 GPH for 59% power, LOP and just a hair under 160 KTAS at 10,000 ft. Add 2 kts/1000 ft and you should see closer to 170 KTAS on 9GPH at 16k.

I found it took a 6% increase in fuel flow to see a 3% increase in TAS. 160 KTAS was kinda my lower threshold for acceptable speed.

Edited July 9, 2019 by KLRDMD

[gsxrpilot]

3 hours ago, willerjim273 said:

I have a really nice 1980 231. My mission is out of Denver and 16k in 30 miles. She does the job well. However, the avionics bug has me. And the exp world is awash. 

 

I am looking for data on how a 10 compares. Here is my basic logic. Using 16k as standard, the 260 Lyc will be at about 15.4" or about 62% power which equates to about 161 HP. We can say the Mooney is still putting out 200 HP. But is it? Most likely we will be LOP and at a lower actual HP. I have a new (rebuilt) Skyways engine and just changed from mineral oil. I am a coward to try LOP because I cannot find anyone in Denver  to be in cockpit with me who knows what they are doing. So I am burning about 13 GPH at 28" and life is good. I am seeing about 160-170 TAS. Anyone have an efis that will tell you what % HP you are when LOP at 16k??

 

After that we have to look at drag etc then compare all sorts of things that get real tricky. The MP comes from this thread..  http://www.vansairforce.com/community/showthread.php?t=88214

 

thoughts, Ideas?

 

2 hours ago, Bryan said:

@gsxrpilot just moved to that area and flies a M20K LOP a lot.  I bet he would go up with you to explore LOP operations in your 231.  He has a great panel for displaying TAS along with FF and MAP settings. My previous bird (231) did LOP great. 

Can (somone) say the Mooney is still putting out 200HP at 16000, yes, at full power setting.  The critical altitude for this is much higher and you will not be losing MAP at 16000 under normal circumstances.  However, pulling the MAP back, RPM back, and FF back, you will be crusing at less than 200HP. 

Thanks @Bryan. @willerjim273 I have an M20K 252 and am based at BJC. I just arrived, been here a month. I'm very comfortable flying LOP in my K and do it anytime I need additional range. 190 knots at 9.5 gph will get you across the country like no other piston single. I'd be happy to fly with you and either show you LOP opps in my 252, or ride with you in your 231 and demonstrate it there. I'm pretty sure I can answer most questions you have about it as well.

One note on the RV10, they are great birds, other than the gear hanging out making them look like a trainer, or worse, a Cirrus.  But seriously, even when I run LOP, with our turbos, we're running full power all the way to cruising altitude. So if the target is 16,000, I'll be making full power, 210 hp all the way to 16,000 ft. Then once leveled off and in cruise, I'll pull back to 65% power and LOP. This means if I need to go up to say FL180, I can push everything forward and I'm back to full 100% power for the quick climb. Or if I get caught in a mountain wave and need to out climb the sink, I've got full 100% power, 210 hp, available to me. The RV10 has a big engine, but at 16,000 it's at partial power, and getting worse the higher you go from there.

I like cruising at 65% power and about 9 or 10 gph at 16K or 18K or 26K, but I also like knowing that I have full 100% power available if I need it.

Send me a PM and I'll shoot you my contact details. I'd be happy to go fly with you.

[thinwing]

I like 32/2500 for positive climbs out of 12 k...say 700 jdm to flight levels

[Cody Stallings]

9 hours ago, Bryan said:

@gsxrpilot just moved to that area and flies a M20K LOP a lot.  I bet he would go up with you to explore LOP operations in your 231.  He has a great panel for displaying TAS along with FF and MAP settings. My previous bird (231) did LOP great. 

Can (somone) say the Mooney is still putting out 200HP at 16000, yes, at full power setting.  The critical altitude for this is much higher and you will not be losing MAP at 16000 under normal circumstances.  However, pulling the MAP back, RPM back, and FF back, you will be crusing at less than 200HP. 

Mine will produce 200hp at 16K at less than full throttle!!!...(: lol

Sorry Bryan, Couldn’t Resist

Edited July 10, 2019 by Cody Stallings

[willerjim273]

On 7/9/2019 at 1:05 PM, jaylw314 said:

Design-wise, the RV-10 is a slippery airframe, with flush riveting everywhere.  Pain in the ass to build, but slippery.  The difference is that the wing is more of a Hershey-bar cross section, so it is somewhat more efficient at higher angles of attack than at higher speeds.

Or you could wait for the Deltahawk diesel motor like I am.  If it ever materializes, you'd have a 200 hp altitude motor that you could run at 100% all the way up to 25k.

Nice engine. I have been stopping by their boot at OSH every year. What can be takin them so long is in red tape, I think.

[jaylw314]

9 minutes ago, willerjim273 said:

Nice engine. I have been stopping by their boot at OSH every year. What can be takin them so long is in red tape, I think.

I know, it's been vaporware for the past 15 years.  That gives Duke Nukem Forever a run for the money 

[PT20J]

On 7/9/2019 at 12:05 PM, jaylw314 said:

Design-wise, the RV-10 is a slippery airframe, with flush riveting everywhere.  Pain in the ass to build, but slippery.  The difference is that the wing is more of a Hershey-bar cross section, so it is somewhat more efficient at higher angles of attack than at higher speeds.

Best discussion of pros and cons of Hershey Bar vs tapered wing I've seen:

https://www.flyingmag.com/rectangular-wings/

[jaylw314]

36 minutes ago, PT20J said:

Best discussion of pros and cons of Hershey Bar vs tapered wing I've seen:

https://www.flyingmag.com/rectangular-wings/

I was thinking more of the thick wing vs thin wing comparison, but that was still a pretty good read nonetheless 

[KRviator]

On 7/10/2019 at 5:05 AM, jaylw314 said:

Design-wise, the RV-10 is a slippery airframe, with flush riveting everywhere.  Pain in the ass to build, but slippery. 

I wouldn't say the RV's are a PITA to build. I built my RV-9 and loved almost every minute of it, and it was just like lego. Yes there were a lot of dimples, but mostly in long, straight rows, and with the DRDT-2 tool, once you get lined up, you can do a row of 100 dimples in under 15 minutes or so.

Best part about the -10? You can deck it out with whatever you want, and maintain it yourself.

Worst part about the -10? You can deck it out with whatever you want, and that "whatever you want" can be horrendously expensive.

[carusoam]

Proof that some guys really like to build things...  ^^^^

Best regards,

-a-

[kellym]

On 7/9/2019 at 12:50 PM, Niko182 said:

There places that a turbo is a nice addition and a turbo is required. If you normally fly out of airports at 5 to 10k ft with density altitudes up to 13k, a non turbo charged is not really an option. Would i take my NA aspirated aircraft to Colorado? yes. would I live there with an NA aircraft? no. Unless you find a RV10 with a Turbo on it, I wouldn't even consider an RV10 for your mission.

Obviously you have never flown an RV-10 or you wouldn't make such a statement.  The only reason for a turbo is to have excess power available to be able to hold an altitude IFR at MEAs of 16K or more. I personally would not want to fly IFR over the Front Range in anything less than a TLS, and better a turbine powered aircraft. The RV-10 has a much better power to weight  ratio than the 231, with 260 hp on usually 2700 lb gross. The airframe is lighter, generally 1600-1650 so it has greater useful load than the K as well. I have zero problems operating out of airports like Prescott, Flagstaff, etc. with my RV-10. My takeoff roll is rarely more than 1500 ft, even out of Salt Lake City. It is about 10 kts faster than my E model was when set to the same hp number, usually operating on around 160 hp to keep fuel consumption down, with about 160-165 TAS, vs the E was about 153 kts on 150 hp.  Now, you will be very hard pressed to find an RV-10 with a turbo, because Vans specifically discourages installing one. The reason is that the design Vne is 200 kts TAS.

If you put a turbo on that allowed you to generate 75% power (195 hp) at 12,000 ft. you would be cruising at or above Vne.

My E model had no trouble getting to 17,500, with published service ceiling of 18,800. However, it had no reserve power to maintain altitude if there was any convective activity.

My RV-10 weighs the same, empty as my E model did, with an extra 60 hp. My climb rates are at least 500 fpm better than the E.  I haven't bothered to find a service ceiling, but others have reported values up into the low 20s.  At any altitude below around 12,000, my RV-10 will be faster than a stock 231, on less fuel.  For the trip to OSH I average about 11.3 gph on 160 kt cruise.

Of course you can probably buy a TLS for what I have in my RV, but not with all avionics less than 10 yrs old. Annual nav/data and charts updates for my Dynon Skyview displays costs about 1/5 what they cost for my GTN 650. I have full 3 axis modern autopilot for about the price of one King replacement servo.

Yes, I took 8 years building my RV-10, but I know others that have built one in as little as 12 months. There usually are several advertised for sale, so no building is required.

 

[carusoam]

Kelly, got any pics of your project?

Although, not really Mooney related... but something an MSer built has got me interested...

And 60 extra hp sounds pretty good too... 

Best regards,

-a-