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Posted

Also search for prince, hertzler, and catto.

.... and IVO if your engine meets the requirements.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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Posted

My contention: The difference between a well tuned fixed pitch prop and a 2700RPM limited CS prop is inconsequential IMO.

 

If you static 2500 (like my climb prop) it gives 93% of available horsepower. Are you willing to pay an extra $12000+ (and maintenance costs) for the other 7%? What was the consequence of not having that 7% on hundreds of thousands of EZ flight hours?

 

At 2700 RPM, the props are similar. Performance is similar. Are you willing to pay an extra $12000+ (and maintenance costs) for similar performance?

 

If you top end 2900 it gives 107% of available horsepower. Are you willing to pay an extra $12000+ (and maintenance costs) for the 7% reduction in top end? (not that you will use it very much).

 

A metal prop would be an advantage, if it could be done, from a damage tolerance point of view. If not, your blades are equally susceptible to damage, given leading edge protection is mutually exclusive.

 

The right prop for these aircraft, on the basis of published test results would be a fixed pitch 2 or 3 blade. 3 blade use, IMO, is predicated on exhaust location. Weight is a demon, eliminate it.

I don't know if you're having a bad day Wayne, but obviously thrust moves airplanes, not horsepower. There's that pesky "propeller efficiency" thing to deal with.

 

IMO the only good reason to go CS in a pusher canard would be to improve low airspeed thrust efficiency (i.e. get off the ground sooner). For some people this is a very valid concern, but not really necessary for most.

 

Do you really mean to suggest that your take-off role would be reduced by only ~7% if you had a CS propeller installed?

Posted

Tyson, agree, I should have listed the caveats in smallprint. Happy for you to go through that data an multiply by the efficiency factors you see for e.g. an MT and a silver bullet for each of the flight profiles. No question. I will be interested to see the resultant deltas between the designs, and compare them to published test data. I believe they will be smaller than you think, and hence I deemed them relatively inconsequential. Given CS prop are essentially a fixed blade design that twists at the hub, they too are set for an optimum flight profile. Is blade design, independant of hub more efficient for a CS prop?

 

Published tests in the CSA newsletter, might be Jack Fehling's 200hp Velocity from memory, were quite telling when comparing the MT to the silver bullet, and I think they included environmental data.

Cheers,

 

Wayne Blackler

IO-360 Long EZ

VH-WEZ (N360WZ)

Melbourne, AUSTRALIA

http://v2.ez.org/feature/F0411-1/F0411-1.htm

Posted

Longez360,

you are succeeding in getting me confused here.

 

If (well tuned) fixed props are equivalent to CS/VP props then why on earth would one pay 10 grand extra ( In that case I d rather give the ten grand to my wife, she also knows how to spend it on useless stuff)

 

In my brief understanding from all these comments above here and some on the props forum. I would say that one can tune a CS/VP prop to be "excellent" in more than one setting, for instance two settings, such as take of and fast cruise. In this case I would not mind paying, then they d be worth the money.

If this is not the case then I am realy lost

 

Thanks guys

 

Ronny

Posted

Tyson, agree, I should have listed the caveats in smallprint. Happy for you to go through that data an multiply by the efficiency factors you see for e.g. an MT and a silver bullet for each of the flight profiles. No question. I will be interested to see the resultant deltas between the designs, and compare them to published test data. I believe they will be smaller than you think, and hence I deemed them relatively inconsequential. Given CS prop are essentially a fixed blade design that twists at the hub, they too are set for an optimum flight profile. Is blade design, independant of hub more efficient for a CS prop?

 

Published tests in the CSA newsletter, might be Jack Fehling's 200hp Velocity from memory, were quite telling when comparing the MT to the silver bullet, and I think they included environmental data.

 

I too am interested in the data. Having had a total of 9 aircraft (including the one that I am building) one fixed pitch prop and 7 constant speed ones, and having flown most other light singles and twins, of both persuasions, I am partial to the constant speed variety.

 

If we remove the twins from consideration since they need the C/S for feathering reasons, in store bought craft I have had, and my dragonfly (airmaster C/S with warp blades) the C/S-CP props give a better climb and shorter t/o distance. There is probably a slight cost in high cruise.

 

Imagine starting your car off from a start in second or third gear.

 

I hope to be proven wrong so I don't have to consider the choice for my aerocanard.

 

There is another advantage to a C/S (constant speed) prop or C/P (cockpit controllable pitch) and that is on landing, when you go to full fine on the approach, the prop acts as a speed brake and makes landing a lot easier. Kinda like an additional belly board (on the ground it doesn't make any difference).

 

There must be a reason why all high performance store bought aircraft come from the factory with expensive, higher maintainence, C/S props with similar downsides to the governors which control them.

 

For low performance aircraft such as 150/2s or 170/2s or smaller pipers and the like, Fixed props are used for simplicity and cost.

 

This is not to say that C/S- C/P props are necessary on our craft. If you always fly out of long enough runways and are satisfied with the rate of climb that can be gotten with a f/P prop, that's great.

 

In store bought Planes that have f/P as standard, there are usually two varieties that are certified. One is the cruise prop, with a certain pitch, the other is a climb prop with a finer pitch. The climb prop being a finer pitch will climb better at the expense of top end. The cruise prop has a better top end, at the expense of climb performance. A C/S -C/P prop allows you to have both of these, cockpit selectable. (I won't go into the mechanism and difference between C/S and C/P here suffice it to say they have similar effects).

 

There are some props which claim to be "Semi constant speed" These props, I believe are designed to actually flex and change their pitch slightly automatically. I have no idea if they actually are better-- anybody out there have one or two??

 

Disclaimer::::::::: I don't know if the above holds true for pushers, however I think that it does.

 

One more thing, for those considering Turbo or other chargers.

 

A C/S C/P is required to achieve maximum use of your setup.

 

As the aircraft ascends, the air, as we all know gets thinner. The charger makes the engine think that it is lower than it is and it is able to produce more power at the thin air altitudes.

 

Not so the prop. Fewer molecules of air are being quesenarted by the prop than at a lower level, and unless you increase the pitch of the prop, it will over-speed as you fly in the rarefied air with more power. To stop your Lyconental parts from flying hither and yon because of this over-speed, you have two choices: 1) reduce throttle setting (in which case you waste the advantage of the turbo) or 2) increase the pitch of the prop-- which you can't do with a F/P

 

Why don't F/P props typically over-speed with Normally aspirated engines at altitude????? The engine is producing less power and because of this the decreased density of the air isn't usually a factor.

I Canardly contain myself!

Rich :D

Posted

Rich, Thank you

 

Sounds all logical to me, thanks for confirming my ideas.

 

Hence : since I need to operate from a shorter field, it can be worth while looking at a Controllable Pitch prop. (Running a O-235)

 

I did get a questionnaire from MT Props,

as soon as I get that filled out will send it in, looking forward to hearing their ideas

 

But thanks guys, please keep on giving me your thoughts

 

Ronny

Posted

We are comparing a variety of apples to a variety of oranges. The old CPs (as well as owner's manuals) listed relative efficiency of a variety of FP propellers from different sources (most of which aren't around any longer).

 

Suffice it to say:

-CS holds no superiority in cruise vs a properly selected "cruise" FP propeller

-FP generally affords the pilot the ability to exceed redline limits imposed on CS propellers (thus FP can utilize a higher horsepower, if the FP pitch is set accordingly). Along this line, top speed could be faster with the FP

-at 5kts, a FP propeller set for efficient cruise at 170kts is simply not going to be anywhere near as efficient at producing thrust as a CS propeller set to fine pitch. How much less efficient, I don't know, but significant. Waiter has written on this previously with some apples-apples discussion.

 

Now, practically, who cares. If one limits operation to longer runways, there is no compelling cruise or range consideration that favors using a CS over FP.

Posted

Hey Ronny.

This is a great topic to discuss with your CFI. He can explain the pros and cons as well as show you examples.

 

Sometimes the decision as to go CS or Fixed is as simple as money.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

Posted

"" Ronny.

This is a great topic to discuss with your CFI. He can explain the pros and cons as well as show you examples.

 

Sometimes the decision as to go CS or Fixed is as simple as money."""

 

Thanks T mann for your comment, please forgive me for asking, probably a real stupid question. But what is a CFI ???

 

Thx

Ronny

Posted

This is a great topic to discuss with your CFI. He can explain the pros and cons as well as show you examples.

If you actually have a CFI (Certified Flight Instructor) who actually understands WHY one might use a CS prop rather than a fixed pitch prop or vice versa, and the theory behind propellers of both types rather than just how to move the pitch lever, I'm impressed. Most of the CFI's I know don't understand how a wing works, much less a propeller.
Posted

Hi Guys,

At MT they are quick, just had a quote.

 

Electric constant speed left handed pusher. MTV - 1 - F/LD 158-03

62", two bladed

 

All included, controller, spinner etc etc 7460 euro's (ex VAT)= 11K USD

 

Anybody have any info on this CS prop

 

Thanks

Ronny

Posted

Hi Guys,

At MT they are quick, just had a quote.

 

Electric constant speed left handed pusher. MTV - 1 - F/LD 158-03

62", two bladed

 

All included, controller, spinner etc etc 7460 euro's (ex VAT)= 11K USD

 

Anybody have any info on this CS prop

 

Thanks

Ronny

if you order one be real careful about the left handed thing. left handed means it is for a pusher configuration using a left rotating engine. this does not mean standard right rotating engine turned around backwards. won't change the price though.

Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

Posted

Ivo will not sell there prop for use on a Lycoming 4 cylinder

Hence the link which has all of the Manufacturer's information. Who would know better than they.

I don't recall a specific power plant discussed in this thread.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

Posted

I don't recall a specific power plant discussed in this thread.

I recall a specific powerplant being mentioned in post #31....

 

Hence : since I need to operate from a shorter field, it can be worth while looking at a Controllable Pitch prop. (Running a O-235)

I suppose a quick call to IVOPROP would answer the question.

Posted

If you plan on running an O-235 then get the fixed pitch climbing prop. You will be underpowered so saving weight and getting off the field should be your primary consideration.

 

It sounds as though you are a long way from picking out a prop so weigh all of your options.

 

For comparison sake (<disclaimer>):

A Lycoming O-235 is going to weigh in at about 250 lbs and produce roughly 120 hp.

That makes for an underpowered Long-EZ.

 

Compare that to a 2 rotor rotary engine producing 200 HP at 290 lbs and now you have more room to work with on those shorted fields.

 

The fact is that if you started a Long-EZ today you would want to save your final engine choice (and avionics) until last. This is due to the advances in technology that are occuring at an ever quickening pace.

 

While a standard Lycoming or Continental may be the fastest/easiest to install there are other options under development that warrant consideration.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

Posted

TMann, Marc, MFreyer, Lynn and all

 

Thanks for all your thoughts

I am unfortunately not building but I am buying an exsisting Long EZ, which has a Lycoming O-235 bolted on.

 

The reason for me looking into the props thing is that I will be operating fom a 800 meters runway. Even though people like Wolf an others have told and shown me that it is possible to operate from this field. I am still looking at all aspects that could have an influence on better take of performance. One of these aspects is the prop.

 

Indeed a fixed pitch climb prop combined with weightsaving is a route.

A CS/VP is another option (Since I live in Belgium, before I will order a prop from MT I will visit them at their factory to check everything out)

Changing engines is also an option

 

Thanks

Ronny

 

Please keep on posting, I am learning more and more every day:cool: :cool:

Posted

TMann Said:

For comparison sake (<disclaimer>):

A Lycoming O-235 is going to weigh in at about 250 lbs and produce roughly 120 hp.

That makes for an underpowered Long-EZ.

 

I built an flew an 0235 C2C Longeze. It was not underpowered. It was an awsome airplane. Full fuel and 2 big guys it flew like a Cessna 152 One big guy (me) and half a tank of fuel it was a sports car. The plane was built light and flew vfr. You dont have to have a fuel guzzling auto motor or a heavier big Lycominig to make a Longeze a nice flying airplane. I built it like Burt said to and it flew like it was supposed to. Quit trying to sell car motors. STeve

Steve Harmon

Lovin Life in Idaho

Cozy IV Plans #1466 N232CZ

http://websites.expercraft.com/bigsteve/

Working on Chapter 19,21

Posted

Quit trying to sell car motors.

I was not referring to 'car motors.'

I'll point to the link where my manufacturer specs came from.

 

An O-235 should give you the performance as outlined by the designer ...... but will not address your concerns.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

Posted

Compare that to a 2 rotor rotary engine producing 200 HP at 290 lbs and now you have more room to work with on those shorted fields.

 

 

you are referring to a motor that you can not even buy if you had the mega bucks they will want for one. I think he is looking for a real world solution to the problem. the 290 lbs. would be great if you did not have to add another 60 lbs. in water oil and radiators to complete the package. not to mention the extra cooling drag caused by all the extra heat these things generate. and then try to fit it all in the back of a long ez.

Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

Posted

you are referring to a motor that you can not even buy if you had the mega bucks they will want for one. I think he is looking for a real world solution to the problem.

In that case here's the link for Real World Solutions, Inc.

Thanks for bringing that one up. I missed it.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

Posted

TMann Said:

 

I built an flew an 0235 C2C Longeze. It was not underpowered. It was an awsome airplane. Full fuel and 2 big guys it flew like a Cessna 152 One big guy (me) and half a tank of fuel it was a sports car. The plane was built light and flew vfr. You dont have to have a fuel guzzling auto motor or a heavier big Lycominig to make a Longeze a nice flying airplane. I built it like Burt said to and it flew like it was supposed to. Quit trying to sell car motors. STeve

 

Well said. I admired your Long EZ in the Canard Pusher Newsletter some years ago. All the best with the new project.

 

If I were to build another Long EZ, I'd look to build the lightest, simplest 'plain vanilla', VFR, O-235 version I could. I would approach is just as Savier, Hertzler and Joe Person have with their Vari Eze's, and enjoy the designer's intent to it's fullest. It would use a fixed pitch propeller without question... I have learned with building and flying my O-360 Long EZ, that complexity is often a drawback. KISS.

 

Ronny, contact Gary Hertzler mate, you will not be dissapointed, I can assure you. Simplicity, elegance, kick ass performance and superb product support.

Cheers,

 

Wayne Blackler

IO-360 Long EZ

VH-WEZ (N360WZ)

Melbourne, AUSTRALIA

http://v2.ez.org/feature/F0411-1/F0411-1.htm

Posted

Wayne

 

Thank you for the advice, where can I find Gary Hertzler

 

And feel free to congratulate me, I just agreed to the purchase of a LOng EZ

O-235, N369R

 

I am afraid I will need to harrass and abuse this board more with all the questions I will have

 

Ronny :P :p :P :p

 

I will check the performance with the current fixed pitch prop and take it from there, but yes of course I will contact Gary Hertzler

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