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  #1  
Old 01-16-2010, 12:45 AM
paul330 paul330 is offline
 
Join Date: Feb 2007
Location: Mpumalanga, South Africa
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Default Adeptair

These guys are making a V6 260-280 normally aspirated or 320 turbo-charged engine in South Africa. This video shows it ground running - very smooth. I want one for my -10

http://www.youtube.com/watch?v=Gl2QiFXl5pA

See them @

http://www.adeptairmotive.com/site/default.asp
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Last edited by paul330 : 01-16-2010 at 12:47 AM. Reason: Add home page URL
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  #2  
Old 01-17-2010, 02:07 PM
breister breister is offline
 
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Location: Atlanta, GA
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I recently heard from them that we shouldn't expect production engines for another 2-3 years. They have at least one test engine, and are partnering with Ravin Aircraft (also in South Africa, they make a kit modeled after the Piper Comanche but in fiberglass) to provide another test engine for evaluation.

Historically, no geared piston engines have survived commercially.

However, I wrote them and told them that if they have trouble with the gear box they should check out Magnomatics - makers of magnetic gears. Cannot break, reduces torque pulses, and automatically "slips" like a clutch if maximum acceptable torque is exceeded (should protect the engine from prop strikes).

More interesting to me is that Ravin is developing a twin version of the Ravin (just like Piper did with the Comanche). If they were to put two of those Adept turbocharged beasties on that airframe, that would be 640 ponies - some quick cube-root-of-horsepower calculations suggest an airplane that could cruise at well over 400mph with the oxygen mask on!

Don't worry though - I'm sure that such an airplane will cost 2-3 times as much as an RV-10 (and well out of my price range), so it will undoubtedly remain the most popular choice.


Last edited by breister : 01-19-2010 at 03:07 PM.
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  #3  
Old 01-18-2010, 11:43 PM
Rainier Lamers Rainier Lamers is offline
 
Join Date: May 2007
Location: Somerset West
Posts: 1,033
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We are very loosly involved (on the EFIS, engine monitoring side) with Adept.
Yes, it is taking time and it is taking longer than expected.
In my opinion this is mostly due to the extreme level of perfection that these guys are aiming towards and are applying to every stage of the development.
Perhaps it could be argued that this is overdone and not in their commercial interest, however, when it is done - expect an engine that is perfect...

Rainier

Quote:
Originally Posted by breister View Post
I recently heard from them that we shouldn't expect production engines for another 2-3 years. They have at least one test engine, and are partnering with Ravin Aircraft (also in South Africa, they make a kit modeled after the Piper Comanche but in fiberglass) to provide another test engine for evaluation.

Historically, no geared piston engines have survived commercially.

However, I wrote them and told them that if they have trouble with the gear box they should check out Magnomatics - makers of magnetic gears. Cannot break, reduces torque pulses, and automatically "slips" like a clutch if maximum acceptable torque is exceeded (should protect the engine from prop strikes).

More interesting to me is that Ravin is developing a twin version of the Ravin (just like Piper did with the Comanche). If they were to put two of those Adept turbocharged beasties on that airframe, that would be 620 ponies - some quick cube-root-of-horsepower calculations suggest an airplane that could cruise at well over 400mph with the oxygen mask on!

Don't worry though - I'm sure that such an airplane will cost 2-3 times as much as an RV-10 (and well out of my price range), so it will undoubtedly remain the most popular choice.

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  #4  
Old 01-19-2010, 03:12 PM
breister breister is offline
 
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I kinda figured they would call on you Ranier!

Well, I for one wish them success. The deck is certainly stacked against them, as every attempt ever to produce an engine which has a high power-to-weight ratio and is also geared has failed. Apparently something about harmonic feedback loops between prop, gearbox, and engine.

A friend has a scale model P-51 (80%?) with a monster 8 cylinder engine that has never flown more than 50 hours without an in-flight emergency. The Orenda engine bombed. The Merlins in the original P-51 never were reliable for more than a few hundred hours. The list goes on and on, and a lot of really smart people have tried and failed.

That's why I'm hopeful that this newfangled magnetic gear technology works out - it could solve a LOT of previously "unsolvable" problems.
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  #5  
Old 01-19-2010, 03:55 PM
SvingenB SvingenB is offline
 
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Location: Norway, Stj?rdal
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Quote:
Originally Posted by breister View Post
I kinda figured they would call on you Ranier!

Well, I for one wish them success. The deck is certainly stacked against them, as every attempt ever to produce an engine which has a high power-to-weight ratio and is also geared has failed. Apparently something about harmonic feedback loops between prop, gearbox, and engine.
Not entirely correct. More than 15,000 units of the Rotax 912 is produced. It is geared and as a very high power to weight ratio, much more than any Lycoming. When knowing what you are doing, there is no problems scaling the power of the Rotax up to any requirement.
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  #6  
Old 01-19-2010, 04:31 PM
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dhammer dhammer is offline
 
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Location: Keller, TX
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Default Geared engines

Quote:
Originally Posted by SvingenB View Post
Not entirely correct. More than 15,000 units of the Rotax 912 is produced. It is geared and as a very high power to weight ratio, much more than any Lycoming. When knowing what you are doing, there is no problems scaling the power of the Rotax up to any requirement.
And don't forget the GTSIO-520 that's on every C-421 built along with a few others that are a bunch more powerful per pound than the Rotax.

Many large engines are geared as well, including the largest Lycoming ever - the R-7755 at 5,000 HP for its 6,050 lbs weight.

Most sucessful of the big ones was the P&W R4360 that made up to 4,300 HP with a weight of around 3,870 lbs. Prop ratio is 0.375:1 and the power to weight ratio averaged 1.11 hp/lb. Over 18,000 were built
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  #7  
Old 01-19-2010, 06:16 PM
paul330 paul330 is offline
 
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Well, I hope they can get it to work. Unfortunately, I don't think it will be ready to meet my timescale and the UK approval process would probably defeat me anyway

My wife is South African and we my well retire to SA in a few years. In that case, it's sell the -10 and build a Ravin with the AdeptAir engine - awesome, if not QUITE as pretty as the -10

See http://www.saravin.com/
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  #8  
Old 01-20-2010, 07:49 AM
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islandmonkey islandmonkey is offline
 
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Default I must respectfully disagree

Quote:
Originally Posted by breister View Post
Historically, no geared piston engines have survived commercially.


Rotax as already mentioned. Commercially very successful.

Thielert to name another but not a commercial success.

The Vedeneyev M14P that powers the YAK 52 is also geared.
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Last edited by islandmonkey : 01-20-2010 at 07:54 AM.
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  #9  
Old 01-20-2010, 11:33 AM
breister breister is offline
 
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Quote:
Originally Posted by SvingenB View Post
Not entirely correct. More than 15,000 units of the Rotax 912 is produced. It is geared and as a very high power to weight ratio, much more than any Lycoming. When knowing what you are doing, there is no problems scaling the power of the Rotax up to any requirement.
I said it wrong - I meant both high-powered and high power-to-weight ratio.

You are incorrect - it is not as simple as scaling it up. If it were, one of the hundreds of major firms over 8 decades who have tried it would have succeeded.

I remain hopeful that someone successfully solves that problem.

On the GTSIO-520, from Wikipedia (and don't go off on whether it is a "scientific source" - I'm sure it can be independently verified and no one cares enough to falsify this...)
Quote:
The GTSIO-520 was not as common and in its most common application (the Cessna 404 and Cessna 421 twin-engine aircraft) it produces 375 horsepower (280 kW). The engine has a reputation of being expensive to maintain and is intolerant of improper pilot technique.[citation needed] When operated properly, most pilots consider the engine to be reliable. Gearing reduces the RPM of the propeller making the engine quieter running than many other engines, although the gearboxes on early versions of this engine were notoriously unreliable. The gearing also adds measurably to the overhauling costs of these engines.
(bold mine)

On the Vedeneyev M14P and the GTSIO-520 - the final power-to-weight ratio of these engines are not teriffically higher than a direct-drive IO-550.

On the Adept Airmotive - even with gearing, it sits at about 1 lb per hp. Given the examples of the M14P and GTSIO-520, it shouldn't be beyond existing engineering to "get it right." What will be more exiting is when we start seeing reliable engines that break the 1:1 barrier.

Last edited by breister : 01-20-2010 at 11:48 AM. Reason: Several edits
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  #10  
Old 01-21-2010, 12:31 PM
SvingenB SvingenB is offline
 
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Quote:
Originally Posted by breister View Post
You are incorrect - it is not as simple as scaling it up. If it were, one of the hundreds of major firms over 8 decades who have tried it would have succeeded.
I think you misunderstood me here. I didn't mean to simply multiply the dimensions with factor x, I meant scaling the power (including every engineering task required to make it work).

This has been discussed to death already, but the main factor for slowdown in engine development is turboprop. The more power, the higher the importance of power to weight, TBO, reliability, ease of maintenance, vibrations and size compared with price. Above 4-500 HP, a turboprop is a better choice commercially. Turboprops are also geared engines. There is nothing inherently unreliable with a gear, it is more a matter of a 500 HP reciprocating engine becoming extremely complex and heavy compared with a turbine.
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