Prop Time... M20C - rain down on me with wisdom Mooniacs!

[Stephen Slate]

I am thinking of tossing the prop on my M20C due to the ECI AD.  How much should I spend and what should I do?  Anyone buy new recently?  what are prices at for a new prop?

 

Can I sell my old prop?  If so what's it worth?

 

Thanks all!

Edited April 26, 2021 by Stephen Slate

[Tim Jodice]

what model airplane do you have? 

[carusoam]

Which discussion would you like to visit?

MT...

Hartzell...

Macauley...

 

How much dough do you want to spend?

Are you building a forever-plane, where 15amu is tolerable?

Would you prefer a pre-flown prop... to save a few AMUs...

 

or would you like to spend a few AMUs to keep the same thing without the annual AD test..?

 

Hit the search button... put in the prop you want... you won’t be alone...

Best regards,

-a-

[Stephen Slate]

9 hours ago, Tim Jodice said:

what model airplane do you have? 

M20C, sorry I forgot that!

 

[Stephen Slate]

9 hours ago, carusoam said:

Which discussion would you like to visit?

MT...

Hartzell...

Macauley...

 

How much dough do you want to spend?

Are you building a forever-plane, where 15amu is tolerable?

Would you prefer a pre-flown prop... to save a few AMUs...

 

or would you like to spend a few AMUs to keep the same thing without the annual AD test..?

 

Hit the search button... put in the prop you want... you won’t be alone...

Best regards,

-a-

Honestly just starting out so NO IDEA what I want... I can spend anything if it makes sense, but what I am looking for is based on the collective here what makes the most sense???   I might put in the coin for an overhaul and. B hub, but have people found that to make sense?  How much is a new prop these Days?   I found from 8 Years ago they were around 10K. AS far as a forever plane... I am still undecided.  I like the cheap miles, but I am normal size, and the planes tight for my family...

[DXB]

11 hours ago, Stephen Slate said:

I am thinking of tossing the prop on my M20C due to the ECI AD.  How much should I spend and what should I do?  Anyone buy new recently?  what are prices at for a new prop?

 

Can I sell my old prop?  If so what's it worth?

 

Thanks all!

This old thread is pretty informative.  

There is a modification that puts red dye oil in the old hub to identify cracks based on leakage.  Page from HC-SL-61-273.pdf   However, hubs can leak for other reasons which are benign, so the modification may not be the best (I have no expertise or opinion, others can weigh in).

Assuming the blades haven't been ground multiple times, installing a new B hub may be the best value option, along with overhauling or merely IRAN'ing the blades. 

Most folks putting a new prop on a C model these days go with the Hartzell Top Prop, which has the cool looking scimitar blades.  It may be a tad quiter and may offer a modest performance benefit, but probably not enough to justify the added expense if keeping your old prop is an option - but definitely price out the comparison - I'm not sure.  The negative is the Top Prop is also heavier, and the added forward CG may negate the cruise speed benefit.

The much lighter composite MT prop would be a neat option if useful load gain is desirable - oddly it's STC'd for the Es and Fs but not for the Cs.  I think @Oscar Avalle managed to get one put on his C with a field approval from his local FSDO and so might be able to guide you on that path.

 

[Tim Jodice]

2 hours ago, Stephen Slate said:

M20C, sorry I forgot that!

 

What are you looking to gain if anything? If you are simply looking to get rid of the AD and have healthy propeller take your propeller Overhaul it with a B hub. That is by far the best value. 

[MIm20c]

Not many B hubs out there and the price has really skyrocketed. At $2 per hour I continue to fly on my AD prop.  In reality, for where I’m located, the 20 min test once or twice a year is no big deal. @Stephen Slate have you looked around your area for convenient shops that perform the ND test?

[Tim Jodice]

32 minutes ago, DXB said:

 Most folks putting a new prop on a C model these days go with the Hartzell Top Prop, which has the cool looking scimitar blades.  It may be a tad quiter and may offer a modest performance benefit.

 

It doesn't. It is documented on Hartzells website the it sacrifices take off performance. Someone on here bought one. If I remember correctly he didn't hate it but was disappointed that it didn't preform any better than the stock propeller. 

[Oscar Avalle]

On 4/26/2021 at 7:55 AM, DXB said:

This old thread is pretty informative.  

There is a modification that puts red dye oil in the old hub to identify cracks based on leakage.  Page from HC-SL-61-273.pdf   However, hubs can leak for other reasons which are benign, so the modification may not be the best (I have no expertise or opinion, others can weigh in).

Assuming the blades haven't been ground multiple times, installing a new B hub may be the best value option, along with overhauling or merely IRAN'ing the blades. 

Most folks putting a new prop on a C model these days go with the Hartzell Top Prop, which has the cool looking scimitar blades.  It may be a tad quiter and may offer a modest performance benefit, but probably not enough to justify the added expense if keeping your old prop is an option - but definitely price out the comparison - I'm not sure.  The negative is the Top Prop is also heavier, and the added forward CG may negate the cruise speed benefit.

The much lighter composite MT prop would be a neat option if useful load gain is desirable - oddly it's STC'd for the Es and Fs but not for the Cs.  I think @Oscar Avalle managed to get one put on his C with a field approval from his local FSDO and so might be able to guide you on that path.

 

Indeed, I had a MT prop installed on my M20C. Not a big deal. Call Larry Schlasinger MT rep for the US. He can assist you. My experience with the MT Prop has been great. Much quieter and smoother operation. No more RPM limitations. 

 

[0TreeLemur]

On 4/26/2021 at 9:36 AM, Tim Jodice said:

It doesn't. It is documented on Hartzells website the it sacrifices take off performance. Someone on here bought one. If I remember correctly he didn't hate it but was disappointed that it didn't preform any better than the stock propeller. 

That was my assessment among others.   Definitely a bit quieter.  No speed difference in cruise.   The Hartzell Top Prop on a C has no rpm limitations.   Infinite ramp appeal when the engine is turned off!

If my prop had had good blades, I'd have overhauled and installed a B hub.  But, alas, my old prop had "undercut" blades, so OH with those blades was not an option.

Good luck.

[Tim Jodice]

1 hour ago, 0TreeLemur said:

If my prop had had good blades, I'd have overhauled and installed a B hub.  But, alas, my old prop had "undercut" blades, so OH with those blades was not an option.

@Stephen Slate I think this is a good starting point. have them do a check on how thick your blades are.

If there isn't enough meat left for them to file off to make the profile then I would agree with @0TreeLemur that a new propeller regardless of which make/model you go with is the best bet.

[Hank]

Seeing this'll fit. Doc will know.

 

[jamesm]

What about the weight difference between the MT versus Hartzell  or Mc Cauley ?

Did you have 2 or 3 blade before?

 

Thanks for sharing,

 

 

[Guest]

8 hours ago, Hank said:

Seeing this'll fit. Doc will know.

 

I believe that it would physically fit, but wouldn’t be approved.

Clarence

[AerostarDriver]

On 4/26/2021 at 10:36 AM, Tim Jodice said:

It doesn't. It is documented on Hartzells website the it sacrifices take off performance. Someone on here bought one. If I remember correctly he didn't hate it but was disappointed that it didn't preform any better than the stock propeller. 

It is a reduction in takeoff performance by 3%, however, on my E model it is an increase in cruse TAS by about 6 knots. Your mileage may vary. The top prop is about 10 pounds heavier then the prop you would be replacing so just kept that in mind.

[Tim Jodice]

8 minutes ago, AerostarDriver said:

It is a reduction in takeoff performance by 3%, however, on my E model it is an increase in cruse TAS by about 6 knots. Your mileage may vary. The top prop is about 10 pounds heavier then the prop you would be replacing so just kept that in mind.

I tried to find the post I have been referring to and I forget what model airplane he had but he reported no gain in speed. 

At the end of the day it is hard to go wrong with a brand new no AD propeller.

On top of that short of hitting something you will get at least one smooth sailing no blade replacement overhaul.

I bring that up because I don't think everyone thinks about the value of hedging future maintenance when buying a brand new prop as opposed to hoping that you can overhaul a 20-30 year SMOH propeller. 

[AerostarDriver]

59 minutes ago, Tim Jodice said:

I tried to find the post I have been referring to and I forget what model airplane he had but he reported no gain in speed. 

At the end of the day it is hard to go wrong with a brand new no AD propeller.

On top of that short of hitting something you will get at least one smooth sailing no blade replacement overhaul.

I bring that up because I don't think everyone thinks about the value of hedging future maintenance when buying a brand new prop as opposed to hoping that you can overhaul a 20-30 year SMOH propeller. 

If I had the budget the MT is a pretty nice prop but I think the Top Prop is about 11K new. I think speed gains will depend on the airplane. My E with the top prop trues out at 157 to 162 knots regularly with only the only two mods being the lasar cowl closure and oil cooler relocation. Before the Top Prop 155 was about all she had.

[Tim Jodice]

5 minutes ago, AerostarDriver said:

If I had the budget the MT is a pretty nice prop but I think the Top Prop is about 11K new. I think speed gains will depend on the airplane. My E with the top prop trues out at 157 to 162 knots regularly with only the only two mods being the lasar cowl closure and oil cooler relocation. Before the Top Prop 155 was about all she had.

If top speed is your goal I would think the 2 blade hartzell is the best. I didn't gain any speed from the MT propeller.

[DXB]

4 hours ago, AerostarDriver said:

It is a reduction in takeoff performance by 3%, however, on my E model it is an increase in cruse TAS by about 6 knots. Your mileage may vary. The top prop is about 10 pounds heavier then the prop you would be replacing so just kept that in mind.

I wonder if the fair comparison is to put enough weight in the back to offset the shift in forward CG from the Top Prop.  My C has a Top Prop and has been widely remarked to be usually fast, with cruise speeds at 70% power at 6000 ft that are in the 152-155kt range.  It already had the prop when I got it, so I'm not sure how much it contributes, if anything.