Do any of you have experience with or can recommend a prop that works very well, even better than others, for effecting a great climb rate for an UL or LSA taildragger?
I'm looking to get an engine at least 80hp, possibly up to 100hp for a new build Ridge Runner, looking around even now for a great prop for short field take-offs. Is there an UL / LSA equivalent to the "Borer" prop?

Ridge Runner wrote:Do any of you have experience with or can recommend a prop that works very well, even better than others, for effecting a great climb rate for an UL or LSA taildragger?
I'm looking to get an engine at least 80hp, possibly up to 100hp for a new build Ridge Runner, looking around even now for a great prop for short field take-offs. Is there an UL / LSA equivalent to the "Borer" prop?

Both Ivo and Warp Drive have ground-adjustable props oriented for the ultralight and LSA weight classes. Ivo has an electric in-flight adjustable pitch prop.

To achieve the "climb" prop performance you're looking for, I'd pick one of these up and pitch it to the desired RPM for max-climb rate. Might take a little experimentation.

Any thoughts or rumors about the Aerolux prop or GSC GTA in-flight adjustable?

http://www.greenskyadventures.com/Prope ... /intro.htm

I had the IVO ground adjustable and then the DUC. Both were good props but it took a lot more fiddling to get each blade of the DUC where I wanted it. Ended up just setting it once for summer and once for winter air. The IVO was so easy that you could tweek it every couple weeks if you wanted or go from cruise to climb pitch with that single center adjustment and tracking was always good. I thought the IVO was great because of that feature.

I see that you mentioned LSA. If you are flying LSA or as a sport pilot, you cant have an in-flight adjustable prop. With that being said, I have the IFA IVO on mine and love it! I dont just set it and forget it, I use the IFA each and every flight. Just like a constant speed, you flatten it out for take off and then roll the pitch in for cruise. If makes a HUGE difference on mine, especially on floats or ski's in deep snow where It may take a little while to get the plane moving forward at a good speed to "unload" the prop.

I see that you mentioned LSA. If you are flying LSA or as a sport pilot, you cant have an in-flight adjustable prop. With that being said, I have the IFA IVO on mine and love it!

Heheheheh...Wouldn't make much difference where I fly at anyway. My "LSA" plane is located in the Philippines. The civil aviation authority there does not recognize the US "sport pilot" rules or "LSA" designations. In fact, a license is not required to fly anything that is considered "home-built", no matter how big or fast it is or how it is outfitted.

That's great you are getting such good performance out of your IVO IFA. What engine, redrive ratio and prop are you using?

right now, 582, C box at 3:1 and 72: IVO IFA 3 blade Ultralight. I am working on a dual ignition 800 that will put out 125-140 HP on take off and plan to run the IVO Medium on that one.

I like the regs you have over there! I just keyed in on the LSA and not your location.

582, C box at 3:1 and 72: IVO IFA 3 blade Ultralight.

That sounds like a good combination there. Any problems with the electrical contacts end of the IFA? Although I'm using a ground-adjustable 68" 2 blade IVO right now and am very happy with it, I'm interested in other options, especially since the new RR will have a bigger engine and be for a much more narrow performance niche (STOL and mountain flying).

I am working on a dual ignition 800 that will put out 125-140 HP

Wow! That's going to be a rocket. But how heavy is the engine? As for me, I can't find any 4 stroke to the weight and power/thrust parameters I am looking for. So it's back to 2 strokes. I'm trying to keep the weight on the new RR engine below 120lbs and the hp at least 80.

I like the regs you have over there! I just keyed in on the LSA and not your location.

no worries! Come over and fly sometime

http://www.yankinandbankin.com

Some will say not to make your 3:1 box a perfect 3:1 with a three blade. There is more chance for harmonic vibration with the firing of the two stroke cylinder recurring at exactly the same point each revolution. I was told the C box (cushioned) helps this but does not eliminate it. It was one down fall of the B gearbox (not a cushioned coupling) which in turn caused a lot of crankshaft problems for Rotax and one main cause for the lowering of the TBO.

Enjoyed the photos. Phillipines are on my to do list.

dirtstrip wrote:Some will say not to make your 3:1 box a perfect 3:1 with a three blade. There is more chance for harmonic vibration with the firing of the two stroke cylinder recurring at exactly the same point each revolution. I was told the C box (cushioned) helps this but does not eliminate it. It was one down fall of the B gearbox (not a cushioned coupling) which in turn caused a lot of crankshaft problems for Rotax and one main cause for the lowering of the TBO.

Enjoyed the photos. Phillipines are on my to do list.

IVO cautions on the 3:1 and 3 blade. In over 200 hrs I have not had the SS tape across the blade roots (per IVO instructions) crack so there is no movement in the blades. I am guessing that having the clutch is the key as the worst impulses seem to be at the lower RPM when warming up. I don't have that issue with the clutch.

The 800 should turn the lil avid into an awesome performer for sure! Double the HP and double the Tq of the 582.

Thanx guys for your input on this.

Including IVO, 72" IFA, I'm considering several other props.

The KoolProp 73" 2-blade http://www.airtrikes.net/propellers.shtml

The AeroLux 70" 3 blade http://www.greenskyadventures.com/Prope ... /intro.htm

The GSC IFA http://www.greenskyadventures.com/gssGTA.htm

Any of you guys know of or use a reliable tip speed/ redrive/ pitch/ rpm/ calculator?

I don't know about the redrive business, but:
prop rpm x diameter (in inches) / 63,360 = tip speed in mph.
I don't know the speed of sound off-hand, but I think the P Ponk website has an online tip speed calculator where you punch in rpm & diameter & it tells you if it's at or near speed of sound & therefore inefficient.
Akavid, what's that 800 engine you're working on? Is that some new model of Rotax?

hotrod150 wrote:I don't know about the redrive business, but:
prop rpm x diameter (in inches) / 63,360 = tip speed in mph.
I don't know the speed of sound off-hand, but I think the P Ponk website has an online tip speed calculator where you punch in rpm & diameter & it tells you if it's at or near speed of sound & therefore inefficient.
Akavid, what's that 800 engine you're working on? Is that some new model of Rotax?

The 800 is an Arctic Cat engine. Dual plugs and very SMOOTH running engine. I would only consider the 06-09 yrs as they changed the compression ratio after 09 and took 4 pounds off the crank. The power is VERY linear on the 800, almost like an electric motor and there have been NO know issues with it in the sleds. I know I have put alot of miles on these engines without one single problem, hence my desire to put one in the plane. As soon as I get the gear box mated to it, I will put it on the stand and do some testing on the ground prior to flying with it to make sure it is up to my expectations.
I am betting that with the EFI I will have less fuel burn than with the 582. I know for certain that the AC 800 gets better mileage than my AC 600 in many side by side tests we have done.

The power is VERY linear on the 800, almost like an electric motor

Do you think you'll get the take-off thrust and short wind-up time that you get now with your Rotax 582?

Also, how much does it weigh with gearbox and starter?

Ridge Runner wrote:

The power is VERY linear on the 800, almost like an electric motor

Do you think you'll get the take-off thrust and short wind-up time that you get now with your Rotax 582?

Also, how much does it weigh with gearbox and starter?

it is going to come out around 15-20 pounds heavier than the 582. The biggest issue will be a functional exhaust system that will fit inside the cowling. I am going to run the stock snowmachine exhaust on the test stand and pitch the prop for that exhaust as my baseline. Then I will start cutting it up and rotating it around to get it to fit in the cowling. Right now I dont have plans to go electric start with this engine. With the EFI, I have never had to pull the rope more than twice even at -20 temps. To put a starter on it would probably mean going to the rotax "E" gear box or getting very creative and making my own electric start ring gear etc.

I know that just cause you double the torque and hp does not translate into double the thrust, however, I am expecting significant improvements over the 582 (seriously, how can the double factors not give your gobs more thrust). If I can take the engine from a dead stand still in a sled from 15-1700 RPM to WOT of 8000 in about 2 seconds, I don't see where it would be any different in spool up times than the 582.

I had planned to have this engine flying by now, but my work schedule has precluded me from doing anything on it for the last 6 months. Starting next month I will be back on my 2 week on 2 week off schedule and I will be able to devote lots of time to getting this engine in the air ( I hope anyway) haha.

avidflyer,
As I recall there was a 583 Rotax used in a Ski Doo snowmobile too. It was similar in many respects to the 582 but the 583 was not recommended by Rotax for use in aircraft. It did not have two independent ignition systems. It may be also that the Artic Cat engine, which is actually built by Suzuki, has only dual plugs and not two independent ignitions. Of course in an experimental you can do pretty much what you want but be aware of the difference. In the case of fuel injection you might want a backup battery for electrical supply in case of battery failure. The old 582 I had used the crankcase pulse tube system for pumping fuel to the carburetor. I plumbed in a Facet electric fuel pump for backup after the pulse tubing to the Mikuni pump failed in flight and I made my second of three forced landings with that old silver top engine. Either way it is better to be redundant with some type backup in the fuel system.
Do you have gear reduction system in mind for this engine and what clutch system is this you described for the prop.

See, I did get back to the thread topic. Almost..

Okay well it sure sounds like an interesting project. Please let us know how things develop..and pix, of course!

As for me, Im looking for the extra hp and thrust, but without the weight. If I end up with a Simonini 110 hp (thanx EZflap for turning me on to that engine), I'll be getting 60 more hp than my existing RR has with the 503, and gaining only 10 to 12 lbs....supposedly. Thats definitely acceptable to me. A big part of this though will be what type and size of prop will be up front.

It will probably be a last minute decision after months of agonizing, tedious comparing. I wish there was some program out there (free?) that figures out thrust for a given hp engine, prop size, rpm, pitch et etc.

Vassilli Takaranov from KoolProp says I should get between 525 to 550 lbs of static thrust with a 100hp engine, a 73" 3 blade KoolProp and 3.06 reduction. For a little plane like the RR, that should be pretty good. I just wonder if the IVO medium IFA would be any better?

Ridge Runner wrote:Okay well it sure sounds like an interesting project. Please let us know how things develop..and pix, of course!

As for me, Im looking for the extra hp and thrust, but without the weight. If I end up with a Simonini 110 hp (thanx EZflap for turning me on to that engine), I'll be getting 60 more hp than my existing RR has with the 503, and gaining only 10 to 12 lbs....supposedly. Thats definitely acceptable to me. A big part of this though will be what type and size of prop will be up front.

It will probably be a last minute decision after months of agonizing, tedious comparing. I wish there was some program out there (free?) that figures out thrust for a given hp engine, prop size, rpm, pitch et etc.

Vassilli Takaranov from KoolProp says I should get between 525 to 550 lbs of static thrust with a 100hp engine, a 73" 3 blade KoolProp and 3.06 reduction. For a little plane like the RR, that should be pretty good. I just wonder if the IVO medium IFA would be any better?

Here is a US company's online calculator.
http://www.culverprops.com/pitchselection.htm

akavidflyer wrote:I had planned to have this engine flying by now, but my work schedule has precluded me from doing anything on it for the last 6 months. Starting next month I will be back on my 2 week on 2 week off schedule and I will be able to devote lots of time to getting this engine in the air ( I hope anyway) haha.

And then he's gonna build me one!

AvidFlyer wrote:

akavidflyer wrote:I had planned to have this engine flying by now, but my work schedule has precluded me from doing anything on it for the last 6 months. Starting next month I will be back on my 2 week on 2 week off schedule and I will be able to devote lots of time to getting this engine in the air ( I hope anyway) haha.

And then he's gonna build me one!

That will be the general plan once I have it proven .