Which Prop Puts Out The Most Thrust [Archive]

StanFoster

04-27-2007, 03:14 AM

Chris: I agree.....however I used to think that static thrust tests told all....but I no longer believe so. I think there are so many variables with all the nasty turbulent air being fed into the prop while in flight. The real true thrust test would be comparing top end speeds.....or watching the VSI with different props. Actual flying conditions. The ground checks are a good indicator but I bet things can change when that prop starts trying to push more turbulent air....especially on the cabin gyros.

I would just for curiousity's sake....like to have been hitched up to that hydraulic thrust test equipment at Bensen Days....and run my IvoProp through various pitch settings..

But again.....I have inflight test comparisons that convinced me.

Stan

CLS447

04-27-2007, 03:53 AM

Well sure ,Stan..... but, we gotta start somewhere, & that would be static.

Then with the prop still on the machine, put it through all the phases of flight.

Surely we could come up with usable results !

Did you read that part about the DUC putting out 50lbs more than the IVO?

I'm sure they tested more than just static! 50lbs could mean the difference between a dog & a decent performer!

CLS447

04-27-2007, 04:00 AM

Also, the curled tip design on the DUC is the same thing that makes the Prince claim thrust & noise reduction.

Obviously ....there must be something here !

MrGrey

04-27-2007, 01:34 PM

I would like to know more about the prop featured on Carter's new jump take-off gyro featured in the latest Rotorcraft magazine.

CLS447

04-27-2007, 02:19 PM

OK, a whole day went by....does anyone know anything about the DUC windspoon prop putting out more thrust ?

Does anyone care ? I do !

I know that Ron A. & Gregg Spicola are running the Kiev HOT PROP on their machines.

Do they work better than the Warp or Ivo ?

How about that Arplast prop ?

I want the most thrust for my machine .

StanFoster

04-27-2007, 06:51 PM

Chris: You are right....the static tests are a place to start. I am sure the DUC windspoon prop is quiet and probably the most efficient prop for a single pitch setting. However...after flying with an adjustable pitch prop....I cant imagine any single pitch prop out performing what a variable pitch prop can do.

If I had one "gear" to have my prop stuck for a compromise...I would leave it in 3rd gear so to speak. Not maximum pitch...but a pitch I can cruise at...and still keep the rpm/s down.

I am going to do some more pitch setting experiments at summer temperatures soon.....to see if I can milk a little more out of my SH. I can without a doubt say that my top end...mid range,....and low end are all at their optimum with a "tickle of the toggle".

I cant imagine any gyro not gaining from having a variable pitch prop...no matter what make of gyro or make of prop. I am completely sold on this.:whoo:

Stan

CLS447

04-28-2007, 01:21 AM

Stan, an in-flight adjustable prop is not allowed on an ELSA,so.....stop rubbing it in !

50 LBS more thrust than an IVO......I gotta see this for myself !

For those not following the Xenon threads, here are some sites for the DUC windspoon prop. I have also emailed the Canadian distributer for info.

http://www.microlightsport.co.uk/Catalogue/New/DUCPROPELLER.htm

http://shayaviation.com/duc.htm

StanFoster

04-28-2007, 02:21 AM

Chris: Hey...I am not rubbing it in...I am strictly talking about performance range of an adjustable prop. The way I understand it...I may be wrong though...is that you can have an adjustable pitch prop on your ELSA...if you cant adjust it while inflight. In other words...you could set the pitch on the ground with the control that is not operable while flying. So if you have a passenger you want to take pitch out for...you set it that way...or if you are going on a cross country and you want to set it for that... This isnt as handy or useful inflight.....but it takes only seconds to put your gyro in what ever "gear" you want to stay in for the flight.

Stan

CLS447

04-28-2007, 02:38 AM

I was kidding ,Stan.

I love the Ivo on my 447(ultralight version). It is so easy to adjust that it would not be necessary to get the electric drive.

Just remember how many turns of the adjuster & which direction & it could be done on the ground in minutes!

I still am thinking about ordering a medium to try. They assured me that I will get more out of it than my Warp. If not I will use their 30 day money back policy.

But this Windspoon really has me wondering.....I am talking 50 lbs more thrust here! Is it possible ?

StanFoster

04-28-2007, 03:04 AM

Chris: I believe it is possible. I mean...it looks to me like the windspoon may be best single pitch prop out there....and I bet the DB's are quieter as they claim.

I do know also that if you can increase your props pitch....throttle your engine back many hundred rpm's....at least your lower cruise speeds would be quieter. I am convinced by just what everyone is telling me when I cruise around my home area. I set my prop to pull down the full throttled engine from 5400 to 4400 rpm.....then throttle back to 3500-3600 rpm and watch the scenery go by at a nice easy pace.....and leaving a much quieter sound print on the ground.

Now....at high cruise settings....I would guess there are quieter props....but when I am "going" somewhere at a high speed cruise....I am higher anyway.

Its nice to have all these confusing decisions to make...:eek:

Stan

CLS447

05-01-2007, 01:42 AM

I have Emailed both the Canadian distributer & the Manufacturer of the DUC windspoon. Awaiting responses.

Sounds like this could be the adjustable version of the famous Prince P-tip prop.

http://www.princeaircraft.com/html/carbon_fiber_brochure.HTM

CLS447

05-01-2007, 02:59 AM

I really want a Prince P-tip but..........

1. Expensive , 50% down.

2. Custom built for each application ( not interchangeable )

3. No money back guarantee.

4.Have heard (can't prove yet) on the RAF & SH , that they cause cabin resonance.

5. Long delivery time.

6. Non adjustable (except mildly by factory)

Other than those reasons, It sounds great , and I would like to try one !

Does anyone have any actual experience with one ?

Mike Stump wrote an article in the PRA mag one time, & claimed it was absolutely the best.

Dave Dewinter had one on his machine(now owned by someone else) & he swore by it ! (60" on EA81 powered Dominator)

Larry Boyer recieved one with the RAF that he got from Washington State.
The previous owner claimed cabin resonance , so he switched back to the Warp .

We plan to do thrust tests on both props & report findings.

I would try his in a second on my machine if......the direction of spin was the same on my machine ! Damn !

Anyway.....it seems that the DUC is using the same principles for efficiency .

WHY

05-01-2007, 08:17 AM

Hi Chris

Terry Eiland ran one on his Sparrow Hawk and told me he really liked it, I got to listen to it at Mentone one year and it was distinctly quiter than other props, both on take off and in the air. On take off, if you had you back to the runway you would not know it from a Cessna 172 taking off. At the time I talked to him he never mentioned anything about cabin resonance.

Tony

WHY

05-01-2007, 08:26 AM

Chris

The only place that I can see a possible resonance issue would be that on the Prince prop, ( which is a 2 blade) both blades pass the upper and lower support structure at the same time, where as with a Warp Drive prop, ( usually a three blade) only one blade at a time is passing the support structure, but the extra blade also is going to produce more noises because as the blade passed the support structure it makes a "pop" noise because of the disturbance of the tip vortex, which by the way is why the "P" tip makes less noise because it greatly reduces the vortex and converts into thrust.

Tony

StanFoster

05-01-2007, 02:43 PM

Chris: At Mentone this year I will let you decide how much quieter my Ivoprop is over what I had. I of course havent heard it from the ground...but I have been told my other prop was obnoxiously loud...and that this one is substantially quieter. It wasnt the only reason I switched, but it was one of them.

I do have the DB's tests with my warp drive going down the runway at 20 feet at high cruise...full power....and minimum cruise. I just havent been able to get the new DB readings with this new prop.

But....I know its quieter in the cabin....I should have taken DB readings there as well.

Stan

CLS447

05-01-2007, 03:40 PM

Stan, I believe the Ivo is quieter , I'm out for max thrust !

Tony, Terry E. is one of the guys that told me about the resonance. That is why he switched back.

I believe that is the one his son has for sale.

CLS447

05-03-2007, 12:43 AM

I still have not had any response from the DUC maker or the Canada dealer.

Bummer, because I am really interested !

Mike G

05-03-2007, 12:57 AM

Try the DUC French site
http://www.duc-helices.com/anglais/choix.htm

They have a version in English.

Mike G

CLS447

05-03-2007, 01:11 AM

Mike, I did send them a detailed email. Also one to the canadian dealer.

Nothing back yet !

I'll be calling Canada soon! I don't know what it costs to call France .

Mike G

05-04-2007, 06:28 AM

Chris if you have a written list of questions I can ring them for you from here in France, I spoke to Mr. Duqueine (the owner) recently because I'm also tempted by their windspoon prop for my Magni. I asked them about using their VP prop and he replied that for a pusher gyro the best prop was the windspoon because it had a much better lowspeed performance and was better adapted to the turbulent air seen by a pusher prop.
I believe that they are fitted as standard to the ELA gyro and that the MT03 may soon have them as well.
Mike G

CLS447

05-05-2007, 01:24 AM

Thanks that would be great. Here is a copy of the Emails that I sent................................... This one to France...

Hello , I live in the USA & I am very interested in the windspoon prop.

There is one here that I know of & it is being used on the Xenon gyro with the 912s 100hp engine.

It has been said that it gave 50 lbs more thrust than the IVO. This is why I am interested. Also very quiet.

I have a gyro using the Subaru EA81 engine with a 2.18 - 1 PSRU. It has about 120 HP. I believe that my prop flange is a 6 - 3/8" bolt X 100mm pattern.

It is a gearbox redrive pusher. Prop turns clockwise when standing behind the machine.

Is it possible for me to use this prop on my machine ?

I have E-mailed your Canadian distributer & got no response.

Any information would be appreciated.

What are the current prices ?

Here is the one that I sent to Canada..............

I am interested in any info you can give me on this prop.

I have a Subaru EA-81 (120HP) pusher.... Spins clockwise looking at the prop from behind the machine.

My prop flange has 6 3/8" bolts in a 100mm pattern. I have room for the 68.5" version (3 blade ? )

Is it available in colors ? How much is it ?

I am just asking basic questions to get started corresponding, but no replies.

Mike, let me know what you find out !

--------------------------------------------------------------------------------
See what's free at AOL.com.

Mike G

05-05-2007, 03:13 AM

Chris

I'll give him a ring on Monday when I'm back in the office (that way I don't pay for the call).
Can you post a bigger photo of your gyro it may help Mr. Duqueine visiualise your machine.

Mike

CLS447

05-05-2007, 03:40 AM

Sure...here is one

StanFoster

05-05-2007, 03:47 AM

Chris: You and Shar bringing that beauty to Mentone? If you do...please enter it for judging. I bet it will get something.

Stan

CLS447

05-05-2007, 04:08 AM

HOPEFULLY it will be coming with !

Mike G

05-07-2007, 05:26 AM

Chris

I spoke to Mr. Duqueine of DUC propellers.

He says that the windspoon used on the Xenon is a 3 DUC FD(R), the R being reinforced. These blades have much more carbon especially in the longitudinal direction to increase strength and rigidity. The reference number for you would be 0101003 (the Xenon is 0101004 because it turns in the other direction.
There would be no problem fitting your hub but it would require an adaptor that is 30 mm (1.18") long. This adaptor also uses 3 dowels to ensure that the bolts are not in shear and it would handle 120 HP without problem.

If you go any further he'd like a drawing of your flange to make the adaptor to match.

He said that these propellers are efficient if they are set run at between 2300 and 2500 (2550 absolute max) at full power.

The direction of rotation is no problem he has them right and left hand.

The dia is 68" (1727mm).

I've read somewhere in one of the threads that this prop has a sort of built in variable pitch. This is incorrect, DUC do a prop called the "Swirl" which has a sort of constant speed effect, he said it was nothing to do with the blade twisting but due to the difference between air flow over the blade at low speed and high speed. He was pretty vague about how this worked, but he said the Swirl was not the prop for a pusher gyro, but more for a fast fixed wing tractor.

The price he gave me for France was 1118.26 euros incl taxes without the adaptor. The first thing to check is what max prop speed you get with your engine/redive combination.

If you need me to contact him again let me know.

Mike G

CLS447

05-08-2007, 01:22 AM

Mike , thank you very much for this info.

Right now my Warp drive is pitched so that I am turning the engine at 5400rpm. With my redrive ratio of 2.18-1, that means the prop is spinning at 2477rpm.

I want to repitch to slow the engine down to 5200 ,giving me a prop speed of 2385. That's great , Right?

First I need to know what the conversion is for Euros to USA dollars.

Also would like to see a picture or drawing of what this adapter will look like. It may be hard to get a price on that adapter until he knows what I need, but a ballpark figure on that would be nice also.

Someone said that the Windspoon gave 50lbs more thrust than the IVO....does he stand by those claims ?

I appreciate you talking to him for me & hope that you can get the answers to these questions.

How will I contact him & who will I have to place my order through ?

Thanks again, I am very interested !

GyroRon

05-08-2007, 04:32 AM

Hey Chris.... I have some air you can put in your tires that is lighter than regular air... And I can get you a gizmo to clamp onto the fuel line that adds 20 horsepower, along with a special airfilter that also adds 20 horsepower..... Oh and I also know of a fuel additive that will increase your horsepower, and while were at it we could put in some Slick 50, as that will not only add horsepower but your engine can run without oil if you forget to check the level and somehow end up dry.

Am I being a smartass? Yes. Why?...... I don't believe the hype on this Duc prop. I would have to be SHOWN that it will give me this extra thrust before I put out my money to buy one. Dollars to Euros... well lets just say that you can figure on about 1500$ US to buy that prop. That is alot of smack for a prop that your buying just because one guy said it makes 50 pounds more thrust than a warpdrive. Show me a particular gyro hooked up to a thrust scale pulling with a warp and then a duc with the 50 pounds difference on the scale and then I would order one too, but my guess is MAYBE 10 more pounds max, or possibly less, you never know.

Remember ROC a few years ago when Maxie Wildes and Dan Leslie thrust tested their gyros? Remember both gyros were absolutely identical other than Dan had a Powerfin and Maxie had a Warp drive prop....... Everyone was expecting Dan to have much more thrust than Maxie with the old tech Warp Drive, but no one expected what happened and that was Maxie making 20 pounds more than ole Dan!

Anyway, I don't believe the hype. I would want to see proof or have a solid bullet proof money back warranty, where you could test it yourself and send it back if it didn't live up to the hype.

Also just FYI, the entire prop hub is made out of carbon Fiber, not Aluminum like Warp and Powerfin and all others. I am not comfortable with a carbon Fiber hub myself.

Aussie_Paul

05-08-2007, 02:37 PM

IMHO noise reduction would be the main benefit of a DUC prop. In Europe they are extrmelly stringent with the noise requirements.

Aussie Paul. :)

Mike G

05-08-2007, 11:17 PM

Chris I'll talk to Mr Dunquine again but I'm pretty sure it's not him who claims that his prop give 50 lb more thust than an IVO (if it was him it would have been 22.7 kg :lol: ). I think this number comes from Raphael Celier, you'd have to go back through the threads to find out where it came from.

For the adaptor he said it would be a modified version of the one he uses for another engine so he should be able to give you a price.

Apart from that I agree with Ron I wouldn't part with any money without some sort of guarantee.

Paul, I agree it looks quieter but based on noise studies I did on centrifugal compressor blade passing noise generation for my work I'm convinced the biggest noise scource for pusher gyros is the (usually) small distance between the prop tip and some part of the structure. On my Magni the prop is very close to the frame and I'm sure that's what causes most of the noise. Fitting a "quieter" prop may give dissapointing results compare to a tractor drive because the interference would always be there. The ELA, MT03 and Xenon may be better in that respect, it would be interesting to know the distance between the prop tip and the nearest structural part.

Mike G

Aussie_Paul

05-09-2007, 12:31 AM

Paul, I agree it looks quieter but based on noise studies I did on centrifugal compressor blade passing noise generation for my work I'm convinced the biggest noise scource for pusher gyros is the (usually) small distance between the prop tip and some part of the structure. On my Magni the prop is very close to the frame and I'm sure that's what causes most of the noise. Fitting a "quieter" prop may give dissapointing results compare to a tractor drive because the interference would always be there. The ELA, MT03 and Xenon may be better in that respect, it would be interesting to know the distance between the prop tip and the nearest structural part.

Mike G

Mike I have found that a props tip speed is the main problem with most props.

Aussie Paul. :)

CLS447

05-09-2007, 01:27 AM

Mike, Thanks for being my communicator, but since my email was never answered, how will I ever talk with him myself.

I'd like it if I could deal with the Canadian distributer & he could handle everything for me,but he never reponded either. I think the phone calls to Canada would be cheaper!

I agree with all of you as to wanting hard facts.

I will probably be ordering an IVO to try. I hate adjusting the Warp, it's a pain in the butt !

Ivo claims that their prop will beat the warp & they will take it back if I am not happy. I'll start there.

Rob Dubin is the best Xenon contact & he could not tell me much about the DUC. Except how quiet it is.

Again......no facts on the thrust !

If nobody does the testing, nobody gets the truth !

I can say that my EA81 with Warp gave me 2 pulls of 520lbs.

Larry B.s 2 RAF's with EJ22s both gave right around 550.

I'd hate to have to go to an engine that weighs 100lbs more, just to gain 30lbs more thrust.

I just want to maximize what I already have.

Thanks guys

Ron, There is another thing that bothers me.....Do you agree that the RAF seems to show lower numbers in thrust as compared to an open machine ?

Look at Jonathan Weis' 700lbs & Jamie Bodies 2.2 did what ? 600?

Why is this ?

Mike G

05-09-2007, 01:45 AM

Paul
Obviously tip speed is a big part, especially for tractors that don't have any hardware near the prop but if it was mainly tip speed, changing from one prop to another wouldn't change the noise because they would both have the same tip speed.

I've watched tractor FW aircraft with the same engine is mine and the difference in noise is noticable.

One of the Magni owners at St Ciers (the French Magni agent's gyro club) told me he noticed that the later Magnis with the radiator and oil cooler moved forward were noticably quieter due to the reduction in interference with the prop. Someone else there said that by raising the engine to the max height in its mounts (don't ask me how) there was a noticable reduction in noise. This all tends to confirm my thinking that you have to keep stationary hardware as far away from the blades (especially the tips) as possible.

One day I'll borrow a noise meter from work and do a spectrum analysis, I'm sure that most of the sound power will be in the blades passing frequency.

Mike

Mike G

05-09-2007, 01:46 AM

Chris

I'd like to know where this 50lb came from. Did somebody actually measure it or is this just typical sales talk?

Mike G

CLS447

05-09-2007, 01:52 AM

Post #22

Xenon.....Xenon performance at Sun & Fun.

Read that.

StanFoster

05-09-2007, 02:03 AM

Mike G mentioned that any part of the structure close to the prop tip makes noise. I do know that the SparrowHawk 11 moved their tail boom support further away from the prop tip and that was one of the reasons.

Stan

Mike G

05-09-2007, 03:13 AM

Thanks for the feedback Stan it conforts my belief.

Chris I've started a thread under "Xenon - DUC prop performance".

Mike G

GyroRon

05-09-2007, 03:48 AM

Chris, On Jonathans machine I think the reason he pulled so much thrust was a combo of a larger 4 blade prop, and a very much carefully built and assembled engine. I wouldn't say it was hot rodded, as that means superchargers and turbos and nitrous in my mind, but it was pumped up with cams and a huge carb and like I said basically a balanced and blueprinted assembly.

Most RAF's and Sparrowhawks have junkyard subarus, bone stock. Who knows the true milage of these engines or how they were maintained or broken in. In the case of the RAF, they usually have a small carb on them in place of the fuel injection and who knows how dialed in the carb really is.....

Also the cabin gyros do have the engine and prop right behind a huge cabin, which could be blocking or disturbing some of the airflow into the prop, giving a lower number than the engine could produce otherwise on a a open machine.

One thing about a RAF, is even with only 550 pounds, I have seen those gyros lift off and fly seemingly well with two big guys in them.

I never watched Jamies machine do a thrustpull, but it too was Hot rodded, with bigger carb and Delta grind cams and so on....

GyroRon

05-09-2007, 03:53 AM

And from what I have seen, the Ivo won't give you more thrust than the Warp. I think they are nearly even in thrust output.

Watching how one small bolt going through the prop on Ultracruisers machine last week, how it completely ruined one of the blades, that really changed my opinion on Ivos.... I know from experience, a Warp drive would have been chipped from that bolt, but easily fixed with some baking soad and superglue.

Changing pitch on the Warp drive does take some time, but how often do you really need to change it?

This Kiev prop on my gyro does seem to make more thrust than a warp drive, but it is also expensive and seems fragile. I wouldn't buy another one to replace it if I needed to.

Chuck Roberg

05-09-2007, 05:44 AM

Yes, it was Raphael Celier who claimed the DUC gave 50# more thrust than the IVO prop. I was there when he was talking about it. I never asked how his research team came up with that number. I just assumed it was a thrust test.

Raphael also stated that the DUC was the only prop, from all that was tested, that could meet the European standards for noise on a gyroplane. The European standard for gyros is 68db. With the DUC prop it came in at 64db.

Raphael also stated most of the noise is from the prop tips being close to something like the keel. The theory of the Windspoon DUC, as it was explained to me, it has the tips curved back. So instead of the shock wave (don't know if shock wave is the proper terminology) hitting the keel at 90 degrees. The curve of the DUC angles the shock wave back stricking the keel at an angle (don't know what the angle is) resulting in less noise.

Whatever the theory. The Zenon is a lot quieter than than any other gyro with that engine size that I heard. How about you guys that were at Bensen Days and Sun and Fun. What did you think of the noise level from the Zenon?

StanFoster

05-09-2007, 04:54 PM

Ron: I have to tone down your "junkyard" engine term. I was told that SparrowHawk has a source for engines that have less than 30,000 miles on them. There are strict polution requirements and these engines get switched out and SparrowHawk ends up with them. They go through them,,,new timing belts...plugs...do all the setup...bore scope them...compression checks...etc. So these engines dont quite fit the picture that is in my mind of a "junkyard engine" These engines never were in a junkyard. I see a "junkyard" engine as an ol beater car...the hood off...and bird nests on the maniflold....

I have had real good running Subarus in both my RAF and my SparrowHawk. Unfortunately I had a minor head gasket leak either all along...or shortly after I started flying. I have been so impressed with the overall performance of my 2.5 that actually am glad the small leak finally just let go. Now I can massage another few horses out of her.

Stan

Chuck Roberg

05-09-2007, 05:14 PM

I had heard the engines in Japan were only good to 40,000 miles because of the polution laws. But I was wrong. I found this.

FACTS AND QUESTIONS

How used are they, or "What about that 40,000 mile story?"

Let's set the record straight right now. Regardless of what rumors you might have heard, there is no point at which car owners in Japan must change their engines or junk their cars. Used engines from Japan are available because of several unique factors. The climate in Japan causes cars to rust out in very short order, usually no more than 7-10 years. The Japanese Car Inspection (JCI), or sha-ken as they call it in Japan, is a very rigorous bi-annual inspection of nearly 50 systems and components on the vehicle. Once a vehicle begins to have serious rust, it cannot pass the JCI, and the vehicle is scrapped. The average Japanese drives his car much less than the average American. Some estimates claim about 50 percent less. Read our blog for more info on the mileage story.

Here's the link;

http://risingsunengines.com/faq

More info from the web site;

The 40,000 Mile Story

Everyday we are asked, "is it true cars in Japan are junked after 40,000 miles?". This is a urban myth. The Japanese government does NOT come and take cars off the road at 40,000 or any other pre-defined mileage.

However, there are real reasons why there are very good, reliable autombile engines and transmissions available from Japan.

First, they put about half the miles on their cars per year as we do in the USA. So, a 10 year old car in Japan might have 50,000 miles on the engine compared to 100,000 on a USA motor.

Second, the Japanese Car Inspection program or sha-ken as they call it in Japan, is a tough bi-annual inspection that every car is subject to. Over 50 systems and components are inspected. The primary reason for failure is body rust. The weather in Japan is like our east coast winter weather--cold and wet. Cars can rust out in 7-10 years.

This combination of light driving loads, rough weather and tough inspection programs has provided us with great access to very good motors and transmissions from Japanese automobiles.

We will NEVER quote you mileage on a motor we offer to you. In fact, unless someone has the entire vehicle with the odometer they cannot really provide you with the exact mileage.

Our focus is on ensuring you that the condition of our engines is excellent no matter what the mileage is. Cleaning, inspection and one-of-a-kind testing is our way of ensuring such quality.

Our next blog post will discuss in detail proper refurbishment and testing protocals. We hope you will visit our web site, www.risingsunengines.com or give us a call (800 660-4664) with your questions.

In any event. The Sparrowhawk engine has a lot less mileage than your typical U.S. used engine.

GyroRon

05-09-2007, 06:51 PM

Junkyard engine..?. Engine pulled from Rusted out Subaru from Japan..?. whatever, who knows other than the guys who sell these engines! But I would not believe for a minute that they - the Japanese public rip out engines at 30 thousand miles and replace them because of some government laws, that is ridiculous! Here in the USA we have strict laws governing emissions and all newer cars and trucks are to be in compliance for well over 100,000 miles, and they do meet those requirements, so there is no reason these engines can't do the same in Japan.

I too agree, Junkyard engine seems like a bad term, but that is what they are, they are engines out of junked cars. I am sure they inspect them and look for oil leaks and do a compression check and whatnot, but they are not new engines nor rebuilt engines, they are simply used engines that are claimed to be low milage.

CLS447

05-10-2007, 01:35 AM

Chuck, Thanks for all that!

I would like to know if that prop really makes 50 more or not.

Expect a call from me soon, I need to speak with you.

Mike G

05-10-2007, 01:53 AM

Chris

My thread on the Xenon hasn't drawn any response yet.

Mike

Mike G

05-10-2007, 03:20 AM

Chris
In post 6 you asked about Arplast props, that's what I have on my Magni, I think they're standard.
Arplast is a French company their website
http://pros.orange.fr/arplast/index.html
is all in French and doesn't give much technical data.
One thing they say about my prop is that there is supposed to be at least 2" radial tip clearance which I don't think the Magni has, I'll measure it next time at the base.

Mike

LARRYEBOYER

05-10-2007, 10:03 AM

Chris and I did some thrust tests last Friday and the numbers prove a couple misnomers. One thought is that fuel injected is better for HP increase. Mybuster! Both the carbed EJ-22 at 15 degrees of pitch and fuel injected Ej-22 put out the same RPM and thrust.So I can conclude the same HP. Second myth. A prince prop outperforms a warp drive by 20%. Not true. We ran the 3 bladed warpdrive on the ej-22 carbed and got 5050 RPM . Apx 520 lbs of thrust. We switched to a Prince P-tip carbon prop. It turned 5150 and 540 lbs of thrust. If I had taked off a little pitch from the Warp, I would gotten more rpm and thrust.therefor, similiar results. Myth busted. Stay with a warp or similiar prop for a lot less money and the 3 blade is smoother.We ran the EJ-22 at 12.5 degrees on the FI engine and got 570lbs at 5450rpm.. Less pitch-more RPM and thrust.Less cruise speed. That IVO inflight adjustable sounds sweet!

jos

05-10-2007, 12:40 PM

I fully agree with you Larryboyer.
I have seen many DUC props on gyroplanes and made comparisons as did many of my customers
The best prop for a gyroplane http://www.aero.lg.ua/index_e.htm
G 1750
An ea 71 subaru or 1600 the little sister of the ea81 puts out 235kg or 500 pounds of static thrust for half the money of the duc on 3 times the lifespan.
Probably noise is less.

JOS

Trez

05-10-2007, 01:38 PM

I fully agree with you Larryboyer.
I have seen many DUC props on gyroplanes and made comparisons as did many of my customers
The best prop for a gyroplane http://www.aero.lg.ua/index_e.htm
JOS

JOS,
How much is the cost of the AERO props? The D1600 would be neat to try on an UltraWhite/Rotax503. What do you think?
Trez (cracker)

jos

05-10-2007, 02:09 PM

The Aero webpage has a dealer list for you.
The worst case scenario I send you one for testing or contact Vadim Perevosnyuk in Lugansk.
A new world will open for you.

JOS

Aussie_Paul

05-10-2007, 02:51 PM

magilla

05-10-2007, 04:09 PM

If the carb was jetted correctly, it would match electronic fuel injection for HP - you can't get better than a perfect stoichiometric ratio for power.

However - change the altitude, temp, etc, and the fuel injection would maintain its power (if its mappable) whereas the carb would need to be rejetted.

Bottom line: carbs aren't always bad - if you spend the time to jet and tune them for your application, they can work as well as fuel injection.

As far as props, I thought two blades were better than three as far as thrust was concerned ????

I thought the only reason you went with three or four blades was if you were size limited. Each blade passes through dirtier air...and becomes less efficient...and you are swinging extra weight, etc etc, etc

I thought that was the general consensus on standard props (I don't know much about the newfangled DUC, Arplast, and Kiev with the scimitar shape)

An extra 2 inches of prop length will outperform an extra blade, any day. Or is that too a myth???

Mike G

05-11-2007, 12:43 AM

Jos the Aero web page says

"In case of observance of all the rules (transportation, exploitation and storage), specified life of the AP is 400 hours."

Do they really mean that the warantee is limited to 400 hours?

Which Aero prop would you put on a 914?

Mike G

CLS447

05-11-2007, 02:27 PM

Larry, in defense of the Prince prop. it only allowed that EJ22 to turn 5030 rpm. The Warp was turning faster. Oh, and by the way, the Prince pulled 560lbs of thrust, whereas the Warp with 15.5 degrees of pitch pulled 550.

I believe that if they were set for the same rpm the Prince would have won!

I liked the way the Prince sounded also. I did not get to fly with it but Larry did. He said that he didn't notice any resonance. I think it needs to be depitched a little to get at least 5250rpm.

We don't know the history of this particular Prince prop....It could have been ordered for an EJ25.

Paul, I agree with what you said about the fuel injection, but Larry was a little dissapointed to see a plain jane carbed EJ22 do as well as his "custom Built" Colorado Component engine.

I would be also. I am curious about the cams in his engine.