Climb Prop Needed

[AKCrate]

Looking for a climb prop for a C-85

Sensenich preferred 76ak-2-40

Let me know what you got used, new, loners ect.... Got any ideas?

I need something that is going to climb at a high altitude strip

Thanks

[Dano"T"]

Re: Climb Prop Needed

76AK-2-40 will only turn up to 2100rpm on a C-85....I tried it....you need a 71" or 72" with 42 or 40 pitch for a C-85....C90 will turn the 76AK-2-40....but not the C85.

[flyguy]

Re: Climb Prop Needed

Just for my edification Dano, does the 76AK-2-40 have a 74" diameter?
Darryl

[T-Rex]

Re: Climb Prop Needed

If you could get a field approval a Sensenich M74CK-40 you would get about 2300 static and will go to redline in flight. I tried one for a little while on T-Rex.The blade profile may be different? But it gives you the length you want. That prop at that length is not approved on any C85 so I dont know what chance you would have at getting one approved.

[AKCrate]

Re: Climb Prop Needed

The prop that came off my A/C was a 76ak-2-40 with a c-85 and it was excellent performer short field as well as cruising at 92mph.


The 76ak-2-40 is actually a 74" prop

thanks for the replies

[gcgilpin]

Re: Climb Prop Needed

I used to run a McCauley 1B90CM7140 on C85. It worked well.

If I remember right it spun up to about 2400+ on takeoff and would hit redline in cruise.

[astjp2]

Re: Climb Prop Needed

I can get you a new sea plane 75-38 inch prop for 2500, I found some for my STC application for using an O-200. I had a 70-40 on my A-80 and it would turn up to 2900 in a shallow dive, Stick with the 74-40 or there abouts and you should be fine... Call Merrill Field propeller, George might have one. Tim

[Mark Julicher]

Re: Climb Prop Needed

We still have the refurbished McCauley 1B90 CM 71-38 available (see buy-sell section) It could be repitched to 40.

[astjp2]

Re: Climb Prop Needed

How many inches was it before for pitch? You only get a total of 8" of change for the life of the prop!

[gcgilpin]

Re: Climb Prop Needed

How many inches was it before for pitch? You only get a total of 8" of change for the life of the prop!

According to an engineer I spoke to from McCauley there is no limit to the amount of pitch changes on the 1B90 props. However, some prop shops will impose their own limit.

Many guys are reluctant to repitch props more than a couple inches. My experience has shown there are no issues, I recently had a 47 pitch twisted to a 40 pitch and it's great... very smooth. Just make sure you use an experienced prop shop.

Before re-pitching the 7138 to 7140 I'd give it a try. A strong C85 will definitely over-rev it in cruise (if you let it) it probably wouldn't during a climb.

[Mark Julicher]

Re: Climb Prop Needed

Our prop was originally a 71 43. I have the yellow tag where it was repitched down to 38.