Time for a new prop

[Wooly]

Our M20J is in need of a new prop. The McCauley blades failed inspection during overhaul. We are considering the Hartzell prop, and would like to hear opinions on the two blade Scimitar or the three blade option. Thanks in advance.

[carusoam]

Welcome aboard Wooly.

You might want to search using the box at the top right of the screen. Search on the words hartzell and TopProp. Click the forum button.

There is a lot of reading in there, including used props and blades for sale....

Good luck,

-a-

[Hank]

I like my Hartzell 3-blade. Many people poo poo the idea on 4-cylinder engines. That's where dynamic balancing comes in. My plane came with this prop, and doesn't vibrate excessively, although some have had that problem.

Cody here is a propeller professional. His experience and advice can be helpful and valuable.

[flyboy0681]

The prop on my '83 J passed inspection this week. I was about to turn blue but I'm breathing again.

[Seth]

I'm getting ready to overhaul my prop. 

 

-Seth

[CCowboy]

Strongly recommend the MT prop.  Is the same price point, is lighter than the metal props.  Have one on the 231, best mod ever, bot better TO and climb with no reduction in cruise performance.  You should at least check it out.

[M20F]

I put a Hartzell Scimitar on when I got my M20F and it also required a new spinner as well due to having SWTA cowling. That got discovered after the prop was hung so a bit of a last minute surprise/expense so make sure when you switch there isn't additional hardware needed.

[Wooly]

I'm getting ready to overhaul my prop. 

 

-Seth

Seth,

Good luck! We just bought the plane in July. The prop hadn't been overhauled since '95, so we were hoping that it would pass, but was not too surprised when it didn't. We factored this into the price so now we will have a new prop up front. We are just trying to make the best decision. This is a great forum and I have reviewed past topics on the matter.

[Seth]

Good luck figuring out the new prop - you've got a lot of good advice.  It's also a good forum with few "trollers" 

 

Everyone here just likes flying - and Mooney's!

 

-Seth

[KSMooniac]

2-blade metal or 3-blade MT, not 3-blade metal.  

[Parker_Woodruff]

2-blade metal or 3-blade MT, not 3-blade metal.  

 

Yep

[orionflt]

there are a lot of people out there that like the MT props but they are not as forgiving when it comes to damage. they are a wood core with a composite coating, they are repairable but it does not take a big nick to require the blade to be replaced. I personally would stay away from them but they do have a good reputation.

 

Brian 

[ArtVandelay]

Possibly stupid questions but...

Can you just replace the blades, not the governor, etc?

How long do props normally last, I didn't know they could wear out?

[N201MKTurbo]

I'm a CB. I would just find a serviceable blade.

 

Props will last until they crack or are ground down till they are too small to meet limits. Props are ground down to remove nicks and to re-profile them at overhaul.

 

To find the real answer you need to look in the overhaul manual and find any Instructions for Continued Airworthiness, and overhaul limits.

[KSMooniac]

They wear out from getting overhauled, frankly, or corroding.  Dressing nicks out also contributes.  

 

The MT props have a stainless steel leading edge bonded to the blade, so they are tougher than aluminum.  The steel edge is replaceable (theoretically), so the blades can last a very long time unless they hit something hard.  The MT is significantly lighter than a 2-blade metal, and REALLY lighter than a 3-blade metal, and that is quite nice for J models and especially K models with forward CG issues.  In some K's you can reduce or remove the "charlie" weights in the tail so your useful load increase is very significant.

 

EDIT:  I'll also add that Hartzell props get repetitive AD's issued when Hartzell needs to boost sales.

[Ftlausa]

What is the concern with the 3 blade metal?  My J came with that prop. 

[N201MKTurbo]

What is the concern with the 3 blade metal?  My J came with that prop. 

 

It looks too cool and they are all jelous!

[KSMooniac]

What is the concern with the 3 blade metal?  My J came with that prop. 

 

They're heavier, don't offer any additional ground clearance or noise reduction (except the MT), slower, prone to vibration on 4 cyl engines, more expensive to buy, more expensive to overhaul.  Other than that, they look great!  

[PTK]

I wouldn't give up the McCauley on the J! It's a mighty fine prop!

Having said that I've heard only good things about the MT. It certainly is pricey though. Its composite and wood material dampens vibration well.

[carusoam]

Thoughts to consider...

1) brittle composite blades that shatter on impact... Does that act of sacrifice, keep the engine from being torn down for inspection....?

2) the four blade composite looks cool on the Acclaim. Reported by the manufacture to be turbine smooth.

3) TopProp scimitar design works really well in conjunction with the 310hp IO550(N) on an O.

4) don't let the new prop hit anything. Modern guidance mandates (most often) pulling the engine for inspection. No more measuring run-out for guidance.

That's all I know about that - Forrest Gump,

-a-

[Guest]

I have an MT on my Comanche 400 as it was the only option to replace my old Hartzell. Hartzell wanted around 40,000 to build a new one and MT was 15,000. It's 38 pounds lighter, much smoother, but as mentioned the are more fragile than an all metal prop.

Clarence

[OR75]

A few things:

Is your prop a C212 ( square tips) or a C214 (round tips) ?

Can your prop be resealed instead of being overhauled ?

If your prop cannot be reaseled, you can either

Look for a used one .... I have one for sale right now ( a C212) . You can look in the for sale section.

Or buy a new one

A used prop will save you about $5000

I just replaced my C212 with a two blade scimitar.

Plenty of discussion on 2 vs 3 blades on this forum and I have nothing to add to that. A question of choice and taste.

Happy to give you my thoughts on the two blades scimitar if you want to.

[KSMooniac]

1) brittle composite blades that shatter on impact... Does that act of sacrifice, keep the engine from being torn down for inspection....?

 

Unfortunately, no.  There is currently no allowance to avoid the tear-down with a composite prop although the probability of a bent crank or other internal damage is essentially nil.

[Jeff_S]

If it were me, I'd go for the Hartzell 2-blade scimitar. I think they look bitchin' and they are supposed to give you some of the climb advantages of the 3-blade without the speed hit.  I had the older 3-blade Hartzell top-prop on my J, which I bought that way, and like Hank I had no problems with it. Never experienced any vibration or anything, and the climb was certainly better than a 2-blade, but I probably did lose a few knots.  I was toying with the idea of replacing it with the scimitar 2-blade but decided to upgrade to an Ovation instead.

 

As the saying goes, there's no replacement for displacement!

[Hank]

I'm getting ready to overhaul my prop.

-Seth

Do you need an overhaul? That means regrinding the blade surfaces. You can have it IRANed to replace seals, fittings, repaint with new decals, etc., and save the blades unless they need to be remilled around the edge or resurfaced on the front.