Nice '67E

[smitty9006]

If you loose a blade with a three blade, you still have two. If you loose a blade on a two blade...

Just trying to lighten it up.

I do appreciate everyone's input though. Thanks.

[Rustler]

KLRDMD--

Your statements do not match any of my experience with 3-blade props. I installed a 3-blade MT composite at annual this year and here are my observations.

          1. The MT, as it came from the factory, is smoother than any 2-blade I've ever had after dynamic balancing (1 on a Cheetah, 2 on a Twin Comanche, and the previous one on this Mooney).

          2. Climb is noticeably enhanced, something very comforting at 7100' MSL where I hangar.

          3. Virtually no decrease in speed at cruise has been experienced. I true at 150, exactly as I did pre-installation.

          4. The prop is significantly quieter and smoother (almost no vibration) at all speeds than the original, particularly enjoyable on long trips.

          5. The MT is about 9 pounds lighter than the 2-blade that was on the plane. That's not a typo.

Just some observations from 60+ hours behind the 3-blade.

I have no connection with MT except to have bought someone there part of his swimming pool.

 

 

 

[KLRDMD]

Quote: Rustler

Your statements do not match any of my experience with 3-blade props. I installed a 3-blade MT composite at annual this year and here are my observations.

[KLRDMD]

Quote: scottfromiowa

Any articles showing vibration as an issue with "3 blades on a 4 cylinder" whether Hartzell or Macaulley?  I not only DON'T concur with your assessment Ken I think you are generalizing here and should NOT be stating this as fact without quoting from a specific reference.  I HAVE flown in two blade Mooney's and I FLY a 3-blade MaCaulley, what I do find is that my climb is SUPERIOR (rate) and the vibration signature at full power (in climb and cruise) while subjective is a NON-issue...Either give me some specific references or STOP stating that 3-blade props have a high "vibration" signature.

[KLRDMD]

I also found this from Aviation Consumer:

In 1998, when Mooney was recertifying the K-model for its brief reintroduction as the Encore, it tested three-blade propellers and found that cruise speed losses were unacceptable in a low horsepower airplane.

The new M20K was reissued with the two-blade prop it had always had. Furthermore, 252s converted to three-blade props in Europe for noise abatement reasons suffered cruise speed losses of 4 to 6 knots, according to Mooney.

On high horsepower engines—say 300 HP and above—it’s a different story. Mooney’s data indicated that with that much power, the extra blade is useful in efficiently converting power to thrust, which is why airplanes such as the Ovation, Bravo and Lancair have three-blade props. Two-blade models would clearly depress climb rates and increase takeoff distances.

[KLRDMD]

Believe anything you want about three blade props on four cylinder engines in Mooneys. I don't just make this stuff up for my own amusement 

[jax88]

Interesting, makes me consider talking to my shop about swapping my three blade for a two blade.  I don't notice any vibration, but I could always use the extra speed.

[scottfromiowa]

I had a 3-blade McCaulley prop installed with overhaul (first overhaul) on my '66 M20E.  I believe WHAT I SEE...No increase in vibration...in fact full power on take-off, climb and cruise appeared to have NO negative impact and or increased noise/sound signature...I wear a Bose because I think all light aircraft are LOUD...I definitely have a reduced ground roll and superior climb for a minimal, if any reduction in cruise.  I would NOT go back to a two blade prop.

I DID read numerous articles that stated that if a prop (two or three blade) is installed mid-engine time NOT with overhaul that the change/balance from the old prop could be different (in the engine) creating an increased vibration.

I BELIEVE NOT WHAT "I WANT", but what I see in MY aircraft.  I would gladly trade a couple of knots and a few pounds in weight for reduced rotation time and increased climb.

And it is "SEXY" 

[Tom]

Quote: KLRDMD

Well . . . 

 . . . also consider this 1966 E that a friend of mine has for sale.

It vRefs at $56,000 today and he wants $53,500. I personally know this airplane have have somewhere between 10 and 20 hours in it myself.

[KLRDMD]

Quote: Tom

The $56K vRef has one error for sure (not a 201 windshield), and one "round up" (Garmin in situ appears to be 430 while vRef cited as 430W...perhaps you could clarify).  Of course the upgrade cost to W is considerable, and doing so would outclass the current S-tec.

[carusoam]

Things to ponder...

[1] 4 cylinder power pulses don't match perfectly with 3 bladed props.

[2] 6 cylinder power pulses match better to 3 bladed props.

[3] Ovations were made with 3 and 2 bladed propellors depending on O1, O2 or O3.

[4] My M20C had a yellow arc for RPM: We were to avoid continuous operation in this arc because of vibration harmonics.  Honestly, I don't think I could feel the harmonics.  I am sure somebody could measure it.  But just because I can't feel it doesn't mean that it isn't harmful. 

[5] High power and High RPM gave plenty of vibration, but that is outside the yellow arc and prior to redline.  Go figure.

[6] Prop balancing is a wonderful thing.  After overhaul things vibrated perceptably less.  I am sure dynamic balancing is good too.

I think the value goes to the newest propeller, one without rpm restrictions or ADs, no matter if it is two or three blades.

-a-

PS Tom,  what was this?

"people interested in Mooneys are typically frugal/efficiency freaks/cheap bastards and this is a buyer's market."

You might look up some threads related to turbos.  You will find the concentration of mooney people willing to pay more to go faster....  There is a balance between efficiency "freaks" and speed "freaks" here.

Then there are the folks who want to go reliably in all conditions.  They will pay more for air conditioning, glass upgrades and FIKI.

There are people willing to pay extra to put glass into M20Cs,  Regardless of wether they will get money back when/if they sell it.

There are mooneys for everyone and every budget.  What a country!

[scottfromiowa]

Carusoam, or as I will call him the "Mooney Whisperer".  Good stuff

[tablor]

Mooney installs any/all props that prop makers send to them - which recently included MT 3 blade.  Whichever yields the highest cruise speed wins.  There have been other composite props and they all were slower.  When McCauley ownership changed to Cessna their engineering dept began to suffer, they weren't supporting Mooney and the change to Hartzell happened.  I was always told the 3 blade AL prop was too heavy for the 200 hp engine and was a bad idea (although I don't know the actual weight difference).  I think if you were looking for takeoff/climb improvement than it would be a reasonable swap.

[danb35]

According to the W&B records for '48Q, the McCauley 3-blade prop is 68 lb., 5 lb. for the spinner.  The Hartzell 3-blade (not sure which model; installed in '97) is 71.35 lb. with the spinner.  The 2-blade now installed (which is the original model) is listed at 53.75 lb., not clear if that includes the spinner or not.

[conom06d]

I don't much care about this little dispute of props...all i know is that my plane looks dead sexy with the polished pointy spinner and 3 blades. As long as my blades dont shoot off when spinning, I am perfectly ok with the miniscule vibrations i get from it...if i even feel it

[carusoam]

I have hard proof that the two bladed prop is more efficient that the three bladed prop....

The three bladed prop can only hold two towels "naturally", the two bladed prop can hold up to four without assistance!

(Add smiley winky face here....)

Best regards,

-a-

[DaV8or]

Quote: smitty9006

I hear you and agree with you Dave. Although I have not flown in the plane, I have spoke with the owner. He is a very nice guy and the plane is almost exacly what I am looking for. I am not too concerned about it not having any speed mods and I like the fact that it has been well looked after. I too think that the extensive logs and records warrent a premium. I just can't take on the expense on an overhaul if I pay 50K plus for a plane.