Hi Fellow Zenith flyers and builders, I'm in the process of fitting a new propeller to my CH701.  I'm running a Rotax 914 turbo (115hp).  I'm not keen on a constant speed propeller, so what propeller would be appropriate to get good results for my aircraft?  If you have any experiences good, bad or otherwise, please let me know. Volkys

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Comment by Harley McCartney on January 17, 2019 at 6:12pm

Hey hope this helps any other 801 drivers out there? 

Comment by Harley McCartney on January 17, 2019 at 5:52pm

Have a fixed pitch 76 sens. fixed to an IO360 Lyc. my home airport is 3375 FT. It will get a meat load off in 700 ft.

at 15 C. My plane is an 801 four seat. It will hold 60 us gallons. Cool with two people four two hundred pounders 

leaves you with a half hour flight ( I always land with 1 hr. reserve). the mountains are not forgiving. Beware density altitude. I would never load to max on a hot day. Sorry I am nobody special 400 hrs ppl 300 in my 801.

Count on $ to service a variable. In Canada it is also an endorsement on your licence and requires a course.

Would I like a variable pitch you bet. Examine the cost carefully.

  

Comment by Sebastian Dewhurst on September 6, 2016 at 10:45am

Hi All, 

I'm a little late to this thread, but thought I'd add my 2 cents...

I've been flying for several years now with a 72" Warp Drive. As my good friend Felipe points out - heavy but reliable. However, no leading edge protection meant that over the years of landing in places an airplane probably should not go, I had a pretty battered prop.

I met with the folks at Sensenich who are just up the road from me here in Florida (I like doing business locally where possible). Their website actually recommends the 68" with a 912S. However, after thinking hard about it, I decided to stick with a 72". Mathematically, a bigger prop will give you more static thrust per horsepower, and with hot humid Florida days and a 600 ft private strip, I didn't want to sacrifice one bit of short field performance. Also, I really like the braking effect of a larger prop at a lower pitch. Really helps with getting the touch down right where you wanted.

I am conscious of the fact that the 68" would have given me a couple more inches of ground clearance, but, I haven't had any issues to date with a 72". I tend not to land on really rough stuff - mainly fields, and dirt roads, and the occasional beach (if nobody is looking). I also know I might have seen a few more knots at cruise - but honestly, if you want to get there fast, rent a Bonanza or fly commercial!

So, I went with the 72", using the super pin indexing system Sensenich provides. I set it first to the 2nd finest pitch available, and then to the finest, and did a test flight each time. Well, in short, a huge disappointment - the prop was nice and quiet, and take off performance wasn't bad, but I was clearly over-propped. Could not get more than 4800 RPM WOT straight and level, even using the finest pitch setting!

The good folks at Sensenich offered to swap out my blades for 68" at no charge (very decent of them given they would not be able to sell the 72" as new). But they also suggested first trying the 72" set to a finer pitch using a conventional digital level rather than the pins.

I'm glad they made this suggestion; a bit of math and a spreadsheet later, I concluded I wanted about 11.5 degrees of pitch to get red-line RPM at best climb speed. Just for interest, I measured the pitch on the old Warp Drive (which had been set by someone else) - wouldn't you know it - 11.5 degrees.

So, I set it to 11.5, and it's perfect. Quiet, spools up almost instantaneously on take off or whenever you add power, reasonable braking effect. And, it looks just perfect (nice of Sensenich to make them in red and white to match N2701D...!). I think Sensenich agreed because they put it on the cover of their new brochure. Pics below.

Comment by Scott Hunter on March 4, 2014 at 12:14pm

Per your question for contacts on the HP conversion, don't have his e-mail, (208)-891-4041 M.S.T., Mark Ferkin.

Comment by Dietrich Ulrich on March 4, 2014 at 5:27am

Thanks Leonard...interesting figures!

Comment by Dietrich Ulrich on March 4, 2014 at 4:06am

Scott, Field elev. in Switzerland is 2'146 ft (grass), at this time I'm spinning a 3-Blade Warp 70" tapered the pitch is set at 9 degree at 2". If I remember correct: at MTOW and best rate, I get 5400+ rpm up to about 5'000ft. I know that I should set for max rpm, however the prop pitch seems already so low for cruise  (high rpm). I have another 3-blade Warp 68" squared...maybe that is a better suit for the 80 horses (we prefer horses over ponies :-)

My plan is to export this airplane to Canada in 2016 and convert it to a floatplane. First flying in the east and then take it into the Rockies for higher altitudes. So your mention of the Kit to increase the 912 from 1211 to 1484 sounds very interesting (as to the turbo alternative). Do you have any contacts for this application?

Comment by Leonard Lewchuk on March 3, 2014 at 5:53pm

Check out Koolprop site. I've got a 69" on my 701 Subaru 100hp.

Comment by Scott Hunter on March 3, 2014 at 2:23pm

I do not know of anyone flying w/80 ponies + floats. Hopefully some one will reply. There is a kit out, but $4,200 U.S.D., increases your 912 from 1211cc to 1484 + comp. from 8.75 to 9.5. There are currently 5 flying in the U.S. w/150 hrs. The 1484 is more than the 1350cc in the  stock 100 ponies. You/ve not stated your home field elev. in Switzerland.

Comment by Dietrich Ulrich on March 3, 2014 at 2:12pm

Scott, Thank you for your info. Actually, with the pilot controlled variable pitch propeller I had the mechanically adjusted pitch control in mind, as GSC offers with the GTA Propeller hub. This has a control knob in the cockpit and with each revolution you optain one degree of propeller pitch. So there is no governor which maintains a pre-set constant speed and while I would watch for airbox temperature, lake trafic and debris I have my concenrns about adjusting the mechanical knob to keep optimal rpm. But as you say Scott, I have a feeling that I won't get much out of the adjustable pitch if the plane stays as draggy as it is :-) 

Comment by Scott Hunter on March 3, 2014 at 12:11pm

Dietrich - As I previously addressed this post, review. However, no, the electric variable pitch IVO 66" Magnum was not a distraction-posted installed a toggle switch on center console. Just set for max T.O. RPM. Cruise-throttle back to cruise RPM, then adjust cruise pitch. 2) Most prop MFG's recommend setting pitch 2" inward from blade tip. The prop flange should be plumb. Often on 2 E.A.B.s currently, I deflate nose wheel, cut 5' 6" 2x6, or 2x8 under tail to obtain the flange to be plumb via level. 3) On a tapered tip, the pitch @ 2" inboard from tip will be 1.5 degrees different than a sq. tip. On my 701 w/turbo as stated, I did not use variable pitch due to the high drag-I just had the same power @ high altitude, would cruise 80-85 mph. As you are in Switzerland, you need full RPM + climb.

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