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Trying out the new Whirlwind!

Ironflight

VAF Moderator / Line Boy
Mentor
Jim Rust was kind enough to send a new Whirlwind 300 series three-blade prop for us to try out on the RV-8 for awhile, and we took it on its maiden flight this morning. Saving 24 pounds on the nose of an RV-8 is a big deal - I used to fly around with a case of oil in the rear baggage compartment to lighten the nose, and taking the big Hartzell off the front does essentially the same thing.

This morning’s flight was basically envelope testing, and the prop did great - nothing poked out, and we flew from stall to redline and did some light acro as well. Engine acceleration is better with the lighter prop, and the quicker response is noticeable. It was already rather warm at 0830 to do good performance measurements, but a very quick and dirty check on speed makes me think we can get the same speed as we did with the BA Hartzell, and climb is improved. More scientific numbers to come.

I wrote up a little more on the installation on the Kitplanes web site:

https://www.kitplanes.com/how-to-save-24-pounds-and-look-great-doing-it/

I’ll let folks know how it goes as we live with this for awhile!

Paul
 
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Very interested in how this works out. I've been eyeing the 74HRT for my -8 build, though the IO-370 is barely into the HP range WW seems to recommend. (but WW told me it'd be fine) Seeing as how the 300 is a new design, and seems more optimized for my choice of engine, it might be a decent alternative.

What really surprised me was the price, which I just checked on the WW site. I figured it'd be significantly more expensive by virtue of being a thee-blade, but it's only listed at $400 more than the HRT. And it weighs six pounds less than the HRT to boot!

You know, I might have just talked myself into this prop in the course of typing this post...

(also, three-blades just look sexier IMO)
 
Very interested in how this works out. I've been eyeing the 74HRT for my -8 build, though the IO-370 is barely into the HP range WW seems to recommend. (but WW told me it'd be fine) Seeing as how the 300 is a new design, and seems more optimized for my choice of engine, it might be a decent alternative.

What really surprised me was the price, which I just checked on the WW site. I figured it'd be significantly more expensive by virtue of being a thee-blade, but it's only listed at $400 more than the HRT. And it weighs six pounds less than the HRT to boot!

You know, I might have just talked myself into this prop in the course of typing this post...

(also, three-blades just look sexier IMO)

I just ordered the 74HRT. After reviewing WW’s requirements for the HRT, I didn’t think my engine had enough HP. I was all set to order the 300 series until I called WW to discuss. After reviewing my engine and mission requirements, they recommended the HRT. It seems the HP required for the HRT is not as high as the website suggests.
 
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I just ordered the 74HRT. After reviewing WW’s requirements for the HRT, I didn’t think my engine had enough HP. I was all set to order the 300 series until I called WW to discuss. After reviewing my engine and mission requirements, they recommended the HRT. It seems the HP required for the HRT is not as high as the website suggests.

Interesting. Could you provide details on your engine and mission? I'm curious what may have driven WW to point you to the HRT vs the 300.
 
Interesting. Could you provide details on your engine and mission? I'm curious what may have driven WW to point you to the HRT vs the 300.

Fuel injected IO-360 with 9:1 pistons. My engine placard says 190HP, but the engine builder claims 195. I do more aerobatics than cross country.
WW said the HRT will give me more bite for aerobatics than the 300 series. They also said I should not lose any top end speed with the HRT vs the 300. The only real draw back is the extra weight with the HRT. My CG is pretty aft at present, so I think the weight of the HRT is actually going to help me out. Truthfully, I was a little disappointed they led me to the HRT. The 300 looks really awesome. They’re the experts, so I went with their recommendation.
 
I will be following this thread closely. I need to decide on a prop over the next few months, either heavy Hartzell or light WW 300 series, with an O-360, 180hp Lycoming for my in-progress RV-8.
 
Jim Rust was kind enough to send a new Whirlwind 300 series three-blade prop for us to try out on the RV-8 for awhile, and we took it on its maiden flight this morning. Saving 24 pounds on the nose of an RV-8 is a big deal - I used to fly around with a case of oil in the rear baggage compartment to lighten the nose, and taking the big Hartzell off the front does essentially the same thing.

This morning’s flight was basically envelope testing, and the prop did great - nothing poked out, and we flew from stall to redline and did some light acro as well. Engine acceleration is better with the lighter prop, and the quicker response is noticeable. It was already rather warm at 0830 to do good performance measurements, but a very quick and dirty check on speed makes me think we can get the same speed as we did with the BA Hartzell, and climb is improved. More scientific numbers to come.

I wrote up a little more on the installation on the Kitplanes web site:

https://www.kitplanes.com/how-to-save-24-pounds-and-look-great-doing-it/

I’ll let folks know how it goes as we live with this for awhile!

Paul

Looks terrific. I'll be very interested to follow your progress and performance testing.
 
I will be following this thread closely. I need to decide on a prop over the next few months, either heavy Hartzell or light WW 300 series, with an O-360, 180hp Lycoming for my in-progress RV-8.

Keep in mind there's also a light composite Hartzell option. Not as light as the 300, but much better than the metal one.

As an added benefit, it'll also reduce the weight of your wallet significantly...
 
Keep in mind there's also a light composite Hartzell option. Not as light as the 300, but much better than the metal one.

As an added benefit, it'll also reduce the weight of your wallet significantly...

I’m sure the composite Hartzell is a fine prop but the WW 300 series sure is sexy! That’s a consideration too!
 
Paul,

What did you use for the moment arm for the prop? I’d like to run a CofG on my 8 swapping the Hartzell BA with the WW 300. I’ve got a rear mounted PC680 with an empty CofG at 78.24. I carry around my tool and tie down kits in the rear baggage when solo.

Look forward to see how your performance trials come out.
 
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Pail,

What did you use for the moment arm for the prop? I’d like to run a CofG on my 8 swapping the Hartzell BA with the WW 300. I’ve got a rear mounted PC680 with an empty CofG at 78.24. I carry around my tool and tie down kits in the rear baggage when solo.

Look forward to see how your performance trials come out.

I plumb-bobbed the airplane a couple of weeks ago, and using the center of the blade ferrules as the center of mass of the prop, I came up with 12" for the prop aft of the datum (which is 70" forward of the wing leading edge). My empty CG moved from 76.88" (with an empty weight of 1100 lbs.)to 78.33" (with an empty weight of 1076 lbs).


Sweet propeller, Paul!

We're both getting ready to hit the 2,000-hour mark, and with 1,525 already on the tach, I may very well consider moving over to the WW 300 depending on the reviews it gets. My IO-360-A1A is still running beautifully, but oil consumption and TBO are definitely converging toward critical mass at which point a new propeller option will be on the table along with a new engine.

Since we build our cowling around the props we intend to use, I am curious as to how it was so simple to swap out a Hartzell for the Whirlwind with different hub measurements. Did they fit the blades to a Hartzell hub? In my case, the forward-facing piston system in the MT hub might make it much more difficult for me to make the crossover when the time comes.

Would switching over to the 300 from the MT 3-blade be doable without having to re-fabricate the cowling?

Thanks for the write-up, Paul!

Scott - I can't speak for going from an MT, but changing Hartzell to the WW-300 was a simple bolt on - the aft edge of the spinners are at exactly the same point relative to the cowl. It's almost as if Jim Rust planned it that way.... The hub is made by Whirlwind, so they could engineer it the way they want, and with so many people building their planes to match a Hartzell, that was probably the marketing choice.

Changing the prop at overhaul is not a bad thing to consider - we are just finishing a complete FWF renewal of the RV-6, and although the prop was operating just fine, we sent it in to Stockton Props for overhaul based on time and years - the overhaul cost $4,500 because it needed an $800 central shaft replacement (due to wear)...a pretty large percentage of a new prop cost!

Paul
 
Keep in mind there's also a light composite Hartzell option. Not as light as the 300, but much better than the metal one.

As an added benefit, it'll also reduce the weight of your wallet significantly...

I went with the Hartzell 8301 Composite blades on my RV-10. Depending on what metal blades you were using, it's at least 16 pounds lighter!! It's an awesome prop and I would do it again in a heartbeat. I was tempted to put it on my Super 8 before the RV-10, but I was afraid I'd never take it off.
 

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Valkyrie looks good in three blades. Happy to see Whirlwind is keeping the light weight dream alive. Smooth as silk says it all.
 
Whirlwind props... but which one?

After reading this discussion I Googled “Whirlwind Propellers” where the first hit led me to the Whirlwind Propeller website; I searched all thru this website and found nothing related to these props being discussed here... so then I Googled “Whirlwind series 300” and up popped Whirl Wind Aviation with a whole different website and set of propellers to look at.

So, what’s the story on this? Whirlwind Propellers (El Cajon, CA) and Whirl Wind Aviation (Austinburg, OH); are they two different companies? Same company, different subsidiaries? A silly and confusing marketing gimmick? Forgive my caveman brain here, I’ve been running a CS blended Hartzell since day 1...

So here’s the website relating to the Whirl Wind Aviation (not Whirlwind Propellers) Series 300;
https://m.whirlwindaviation.com/props/300series.asp

And here’s the page relating to the HRTs being discussed;
https://m.whirlwindaviation.com/props/index.asp

Beautiful props! But priced at $12500, I think I’ll stick with my old Hartzell.
 
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IIRC, one is constant speed, other is ground adjustable.Two different companies, but related.

I think I remember one makes all the blades, other makes the C/S hub and assembles them with the blades from the other company.

Or, maybe I am just getting senile?
 
Yeah....I was looking for some data and ran into the same “two web site” problem John. But here’s the scoop as I understand it.....

Jim Rust is the creative genius behind everything that says “Whirlwind”. He’s located in El Cajon (next door to Robbie Grove - they have a Reno Racer together). He designs everything - blades and hubs - for fixed pitch, ground adjustable, constant sped. he does props for airplanes, ultralights, air boats, wind tunnels, and UAV’s. He sells and markets all of those through Whirlwind Propellers in SOCAL.

Whirlwind Aviation sells and supports the constant speed line - Jim makes the raw blades and hubs, then sends them to Ohio for finishing, assembly, and sales. The Ohio group is aligned with (I think they share facilities and the owner) Titan Aircraft - maker fo the T-51 kits. As I understand it, the arrangement got started when Titan wanted some custom four-blade C/S props to make the T-51’s look right, and that got Jim designing props for them. I honestly don’t know how the current arrangements and split in responsibilities developed.

Now the interesting thing to me is that the new 300 came direct (to me) from SOCAL, not Ohio - but that doesn’t seem that odd since it is new, and I am giving Jim feedback on it. The blades have the “Whirlwind Propeller” logo on them, not the “Whirlwind Aviation“ That is on our -151 (which came from Ohio).

Paul
 
Whew! That's a good explanation, thanks Paul!

Seriously though, my first 10 minutes down the google rabbit hole trying to find and then comprehend the props from two different (yet related?) companies and websites... I thought I'd been snacking down on some crazy pills! From a marketing perspective, shouldn't they try to sorta tie their products together on one single website? I'm neither a rocket surgeon nor a marketing genius, but the way they're doing it just seems really odd...

I'll admit, that new 3 blade on the Val just looks fantastic... plus it's lighter with good performance? Man, I want one! But the price differential, ouch. Like Scott C posted above, at 1700+ hours on my engine, my TBO and oil consumption are trending towards a large $$ expenditure already... might be looking at a top overhaul at least for my old ECI Cerminil jugs.
 
Looks like its only good for a max of 8.5:1 for the IO-360?

I agree - that is what their web site says right now. I have been to Whirlwind’s facility and seen props pretty heavily instrumented for testing, and have seen videos of them doing testing on various engine/prop combinations, so I know that Jim is very serious about making sure the props are safe for the engines on which they are approved.

We flew the prop again yesterday and did some preliminary performance numbers - I don't consider anything final until we’ve repeated the tests a few times for consistency, but It looks like takeoff performance is better, top speed is about the same, and climb is improved.

Gotta give the other airplanes some love, then back to the Val next week!

Paul
 
I know the whirlwind guys browse in here so I'll ask. What's the average cost and timeline for the 650 hour overhaul on the 300 series? Is your turn around time closer to 2 weeks or 2 months once you receive it? Is it going to socal or Ohio for the service? The owners manual says see the placard that came with your prop for overhaul schedule, but without buying one first, I don't have access to a placard for the definitive schedule.
 
I know the whirlwind guys browse in here so I'll ask. What's the average cost and timeline for the 650 hour overhaul on the 300 series? Is your turn around time closer to 2 weeks or 2 months once you receive it? Is it going to socal or Ohio for the service? The owners manual says see the placard that came with your prop for overhaul schedule, but without buying one first, I don't have access to a placard for the definitive schedule.

300 series teardown inspection (TDI) time is 500 hrs, but that will increase over the next year. TDI can be done in SoCal, Ohio, or other propeller shops around the country. Here in Southern California our cost is $500 and turn around time less than a week.
 
300 series teardown inspection (TDI) time is 500 hrs, but that will increase over the next year. TDI can be done in SoCal, Ohio, or other propeller shops around the country. Here in Southern California our cost is $500 and turn around time less than a week.

My manual from my 300-70RV prop purchased in April, 2020 says 650 hours.
 
My 300-72 prop with blade serial numbers 001, 002, and 003 say 650 hr service as well. 85 hours so far and performing great.
Jack
 
Some Testing Data....

I promised a few preliminary testing results on the new WW-300 series on the Valkyrie, and here they are! I’ll be doing some more comprehensive testing as time goes by, but this should keep people from wondering….

I did speed runs at WOT, leaned for peak power, at a Density Altitude of 8,000’, at different RPM's. Finally, I did a time-to-climb between 10,000 and 11,000 Density Altitude using the best climb speed of 95 KIAS (previously determined to be best rate for that altitude), WOT leaned for best power, and full RPM. Fuel was full at engine start for both cases, all loading the same (but the airplane is 24 lbs lighter with the WW).

Why so high? We live at 4400’, and it is August! 8,000 DA was just a touch above pattern altitude…..

Take-off Data (4400’ msl, DA= 5900’):

Hartzell BA WW-300
Time to liftoff 15.3 Seconds 14.0 Seconds
Distance to liftoff 983’ 823’


Speed Data (8,000’ Density Altitude, WOT, Leaned to Peak Power)

KTAS KTAS
RPM Hartzell BA WW-300

2700 173 173
2600 175 174
2500 172 172
2400 170 171
2300 169 170


Climb Data (95 KIAS, 111 KTAS, between 10,000-11,000 Density Altitude, WOT, 2700 RPM, Best Power)

Hartzell 59 Seconds 1016 fpm
WW-300 54 Seconds 1111 fpm

Sorry about the formatting - Pasting from WORD always messes up tabs...
 
So, any more thoughts on the new prop? Not that it matters to me in particular since I already ordered a 300-72, but I can dream of my finished plane in data. :)
 
So, any more thoughts on the new prop? Not that it matters to me in particular since I already ordered a 300-72, but I can dream of my finished plane in data. :)

Still doing great! We’ve got about 10 hours on it and I’m enjoying the much lighter nose on the -8.
 
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