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rls14
01-20-2012, 04:43 PM
I'm in the market for a prop for my Rocket. Whirlwind has a nice looking prop, as well as MT. Any opinions on there respective 3 blade offerings.
Thanks Ron

Bill Dicus
01-20-2012, 05:21 PM
We have a 3 blade MT prop on our Pitts S-2A. It noticeably underperforms the 2 blade Hartzell we had before. If you get a new one it might have an improved blade design and perform better. No data on other 3-blade props on same airframe. Are you flying now with a 2-blade?

rls14
01-20-2012, 06:14 PM
I know 2 blades perform a bit better, but 3 are much smoother. I will have the
F-1 flying this summer an cant make my mind up which prop performs best. I had an MT on the 8 an loved it, but Rick Gray swears by the whirlwind. MT 3 grand cheaper

logansc
01-20-2012, 07:02 PM
No prop is perfect, so you always give up a little here to get something there, but nowadays the better ones are pretty closely matched. As I understand it, most F1 Rockets are flying with either the Hartzell BA two-blades or MT three bladed props. A few apparently have Whirlwinds. You don't really hear anyone complaining about any of them. Pretty rare too apparently, for anyone to swap one out for the other---everyone is happy enough (I guess) with what they have. I have an MT 3-blade on mine (I'm pretty sure a majority of F1's do) and though I'm told there are (approx) 3 knots to be had by going with a Hartzell, I like the lighter weight, climb performance, and the smoothness of the MT.

If you like the looks of the two-blade best then you get a little speed for 'free'. If you like the looks of a 3-blade better, then you get better climb and a smoother engine, for 'free'. How can you go wrong? Frankly, I bought mine
on it's looks and Mark had a good catalog price to boot that sweetened the deal.

Lee...

Tom Martin
01-20-2012, 07:24 PM
I have owned two rockets with the old paddle style blades. They caused a "thump" that you really noticed in smooth air. Apparently clocking them a different direction will help with that issue but I was not aware of that when I owned them. I did swap one of those for a three blade MT. It was very smooth but I promptly lost 4 knots and it took me a year of tweaking the rest of the airplane to get that back. My first F1 rocket had a three blade Hartzell. Now this is a smooth prop but 22 lbs heavier then a two blade Hartzell or a three blade MT. It would be a good prop if you had an EVO wing to help shift a bit of weight forward. It tended to make the pitch forces a bit heavy but also helped make it more stable in pitch.
My current EVO started with a three blade MT. You know what it is like to drive a car that has a four speed transmission and you feel it really needs a fifth gear? That is how it felt on my airplane. I swapped it out for a BA two blade Hartzell and picked up EIGHT KNOTS, on the top end speed. Below 2400 rpm there is not much speed difference and no fuel difference. It is a very smooth prop, I was pleasantly surprised. Is it as smooth as the MT? very close, but I really feel that the engine likes those metal blades. The engine shuts down less abruptly and has enough flywheel effect to make starting easier. I forget exactly but I believe it was 5 pounds heavier then the MT.
I like the metal blades and the fact that it is made in the US. I have no experience with the Whirlwind, it is a nice looking prop but more expensive. Made in the US is also an advantage.
On the ground three blades do have a nice look but they do not look as good when I easily slide past them!

pierre smith
01-21-2012, 05:43 AM
At 200 MPH, no one notices.:)

My two-blade BA Hartzell is around 7 knots faster than my friends 300 horse -10, compared to my 260 horse -10.

What's the priority....smoothness or speed? Seems that a Rocket owner has it for speed, no?

Best,

Kahuna
01-21-2012, 06:06 AM
Tom nailed it pretty well.
My saga of the MT 3-blade is here (http://mstewart.net/super8/performance/propcomparisons.htm).
Short version. MT was so slow I returned it.

rv6rick
01-21-2012, 11:12 AM
Prop for a Rocket is a no brainer for me. I've flown my Whirlwind 3 bladed prop alongside of most of the usual rocket/prop combinations. You always have to keep in mind that some planes are a little heavier or lighter or have this or that built in to make it a bit slower or faster. All I can say is that I wouldn't trade the looks, smoothness, light weight, or performance of the Whirlwind for any of the other props on the market. That's me.

Yes...I am a dealer for Whirlwind, but my decision to purchase their props was made up long before they asked me to be a dealer. I only agreed to be a dealer because I KNOW how their props perform and I KNOW that they stand behind their product long after you make your purchase.

Gather the info then buy what you think will best suit your needs and budget. If money is an issue...I get a 10% discount on the WW ;).

EDIT - forgot to mention that the SOUND of the 3 bladed Whirlwind is like NO OTHER. If you listen to a tape of all the props on the Rockets your ears would pick the Whirlwind everytime....my opinion of course....sound is in the ears of the beholder :).

sailvi767
01-21-2012, 11:30 AM
How much additional clearance do you gain avoiding a prop strike with a 3 blade verses a 2? Is it something thats a non event because if you reach the point with a two where you might hit the prop with a 2 blade you are going over on the nose anyway or is it something to be considered when making a choice? I have noticed that a lot of Rockets have had prop strikes.

George

rv6rick
01-21-2012, 12:53 PM
I don't have the distance measurement in front of me but I could measure my 3 blade in level attitude and have someone else do the same with their 2 blade and report back. That said I don't think it's and issue either way. I'd have to agree that if you 'almost' went over you'd have a better chance of a strike with the 2 blade (stating the obvious).

As far as your comment "I have noticed that a lot of Rockets have had prop strikes".....I think a specific count of "strikes vs. Rockets" flying would be helpful, I wouldn't want folks to get the impression that Rockets are any more prone to a flip over than an RV or 'other'. I am aware of 2 flip overs and they were both Harmon Rockets. The Harmon Rocket is very light on the tail compared to the F1 Rocket. The mount/gear leg socket on the F1 was designed (among other things) to shift more weight back to the tail which IMO was a big improvement. I'm sure Mark F. will jump in here if my comment is too far from reality ;). Doesn't mean they never happened but I'm unaware of any F1 strikes.

Probably a good time for a couple F1 Rocket/Whirlwind prop combo pics :D:

http://img805.imageshack.us/img805/9827/img0644g.jpg (http://imageshack.us/photo/my-images/805/img0644g.jpg/)

http://img688.imageshack.us/img688/6114/2v2e34683487.jpg (http://imageshack.us/photo/my-images/688/2v2e34683487.jpg/)







How much additional clearance do you gain avoiding a prop strike with a 3 blade verses a 2? Is it something thats a non event because if you reach the point with a two where you might hit the prop with a 2 blade you are going over on the nose anyway or is it something to be considered when making a choice? I have noticed that a lot of Rockets have had prop strikes.

George

F1Boss
01-23-2012, 09:03 AM
Hey Ron:

I see you asked specifically about 3 blade props.

The Hartzell 3 blade would be the best for an Evo; the MT 3 blade would be the best 3 blade for the Sport wing (weight differences).

I cannot offer any data on the Whirlwind - no one has raced any of those, and there is no side-by-side flight comparison data either. Keep in mind those props are not certified. I asked for one to flight test, and was refused. I said I'd buy one for testing, but if it didn't perform as the producer said it would, I would get my $$$ back. Again, NO. So, I wrote that brand off as 'claims with no proof', thus I can not recommend that brand, no matter how good they look.

The diameter of the MT & Hartzell props is ~80", with the 3 blade versions being maybe 79.5". So, ground clearance is arguably the same for all.

If you are going racing:
Sincerely, the Hartzell 2 blade is the fastest, and it is almost as smooth as the MT; weight is within 1/2lb. It does carry a bit of the 2 blade thump, but not much. I have an MT laying on the floor of my hangar, and I have not put it back on, and likely won't. If you are interested in such, I can look into having it switched to a Lyc hub, as it currently has the TCM style hub on it. Email me off-list for further info.

Speed gain: I went from ~248mph to ~262mph at Reno by switching to the Hartzell 2 blade. There was at least 5lbs of tape and some waxing involved, and maybe a tiny bit of pilot skill improvement too, but the prop change was at the heart of the gain.

Prop strikes: My last tally on prop strikes was that ~20% of the HR2 fleet had been over on its nose. This is old data, and maybe the percentage is better? or worse? I know of 1 F1 that required a new prop etc due to a 'nose-up' strike, and this incident was caused by a bad starting technique (wide open throttle while cranking). I am not counting ground-loops or running into stuff in either case. So, you are pretty safe in the F1, unless you are distracted while taxiing and hit something.

Carry on!
Mark

rvmills
01-23-2012, 10:25 PM
Ron,

Super Six, not a Rocket, but I just swapped from a Hartzell D-Twist Paddle to a Hartzell BA. Gained the hoped-for 4-5 knots, and went from the thump to butter smooth. Great prop. But that's the 2-blade world, and you opened with three blades...

Just for comparisons sake in your search, I chased Mark around with his MT last year and traded races with him. With his new Hartzell BA, I couldn't touch him at Reno, so his speed gains are real. Now of course, his spray bars and a few other Team Rocket Skunk Works mods may have helped too ;), but as he said, the lion's share was the prop (MT to BA).

It'll be interesting to see what speed Greg Nelson gets if he ever switches his MT to a BA...though he has been heard to say "never", because the MT is so smooth. I think he was waivering after Mark's performance in Reno.

I too would love to see a side-by-side with the WW! I love the elliptical lines of that prop, and have always wondered if that shape adds speed, the way Paul Lipps' Elippse props did. Rick, that is one purty prop for that gorgeous machine, that's for sure. 3 blades are just dang sexy, for sure!

Good luck Ron...its a nice dilemma to contemplate! :)

Cheers,
Bob

Toobuilder
01-24-2012, 06:45 AM
...It'll be interesting to see what speed Greg Nelson gets if he ever switches his MT to a BA...though he has been heard to say "never", because the MT is so smooth. I think he was waivering after Mark's performance in Reno...

...I can confirm that "never" is out of his vocabulary now...