Jump to content

Recommended Posts

Posted

I need to replace my McCauley 3 blade and considering going back to 2. It’s for my 80 M20K. Thinking the 4K difference isn’t worth it. Won’t I get more speed from the two blade anyhow?

Posted

Brian you might want to load in a few more details regarding your engine and prop...

and what you would like to have...

Some Ks have an MT four blade...

The classic 2 vs. 3blade discussion is a compromise...

Which one is best for you?

Do you prefer...

1) Short T/O, faster climb rate... or...

2) Faster Cruise speed...

 

How do you feel about composite props...

Fill in as many details as you can, and people will supply some informed answers...

Including our prop guy who flys an M20K... :)

Best regards,

-a-

Posted
1 hour ago, Briant said:

It was a gear up landing. My preference would be cruise speed.

I looked at MT page and only saw 3 blade for M20K. But that may still be better than McCauley?

The 4 blade isnt available for a k. only for a rocket. the 3 blade MT's available. After flying both a 2 and a 3 blade, I could never go back to a 2. If price wasn't a factor, I probably would have gone 4 blade. The 3 blade carbon is I think around 13 to 15K. A used prop is significantly cheaper than that.

Posted (edited)

The K has a lot of takeoff power regardless of what prop is on it. It is not the kind of plane that you use for short field/obstacle clearance takeoffs very often. You spend most of your time at cruise so why give up your cruise speed? The three blades made a splash when they first came out, but I still don’t see very many of them on K’s as I fly around the country.  There was quite a bit of discussion about two vs. three on this forum a number of years ago, I think the consensus was that the two is the best blade for the “low” horsepower K’s, that you need to get up in the high 200’s to really benefit from a three much less a four. There were also some vibration issues as I recall. At any rate, when I replaced my prop four or five years ago I put a new two blade on. Don’t regret it.

Edited by jlunseth
  • Like 2
Posted

2 vs 3 blade props... and near 200hp...

1) On Mooneys they are all the same diameter.... give or take...

2) 3 blades are better for T/O and climb.... Better at getting the power delivered...

3) 2 blades is best for cruise speed... the drag of the extra blade actually counts...

4) more blades are required for more HP... usually 100hp per blade...

5) Then decide if +1 or -1 makes a difference for your taste...

6) Some Eagles got delivered with a two blade prop...with lowered HP rating for their engine...

 

Then include our prop guy.... @Cody Stallings

Posted

Vibration wise the 3 blade prop on a K seems to play much better with the 6 cyl engine.

Does help in climb, but after that I think it’s just sexy Ramp appeal. 
A K Model being utilized properly will spend its life in the Teens or low Flight Levels an a 3 blade prop isn’t worth piss there, unless it on a bigger higher HP engine.

The folks in Kerrville understood what was needed propeller wise an installed the proper propeller for the intended applications mission.

The C221 on the K’s is a great propeller.

Personal option:

Would have like to seen the narrow blade that’s used on the early Ovation or Eagles used with the 220hp 252’s.

It would have used a little more runway getting off the grd, but that blade is much easier to twist than the wider chord blades that are in the C221 propeller in Cruise.

But one can only dream. That’s why there are engineers that are on a completely different pay grade making those decisions.

  • Like 3

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.