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Borer prop benefits pros/cons

I run an 82/42 150hp cub on Amphibs. Slow as molasses, but gets me off the water well. It will run past 2700rpm in cruise, 2500rpm/87mph. I get the min required per stc static rpm.
 
I run a 82 41 on a 150hp Pa12 with EDO 2000's, cruises 90 at 2400 rpm. it was pitched 43 during its life before I owned the plane but I'm guessing 41 was better because it was put back the next season if I remember correctly. I have no complaints but its all I know for a PA12 on floats besides the stock 100hp no flaps 12 I did my float rating in, that was a pig getting off the water compared to mine.
 
I’ve been running a 8241 on my 160 hp cub since 2005 but mostly on bushwheels. Spent part of two summers on EDO 2000’s a few years ago. Even fully loaded, my 8241 was really quick off the water on the EDO’s. My suggestion is to go with the 8242 and adjust from there. You can have it re-pitched up or down based on what you learn.

Another thought is to wait for Sensenich to get their new ground adjustable prop STC’d for the 320. Based on the few comments I have seen, it looks to be a fantastic prop. Thinking of getting one myself.

Jeff


Sent from my iPad using SuperCub.Org
 
Awesome, thanks LC, Jeff, and MoJo, all good info, I'll take anything I can get :) I'll have to look into it for sure, I'm gathering that the Borer is pretty heavy in comparison, from reading the few threads that I have. I do need to stick with the certified / STC'd stuff. It's going to be a bit before budget allows anything, first floats then prop, hopefully pretty close to each other timewise, thanks again all, C
 
We have run an MT constant speed with reverse for around 10 years now on floats. Definitely better bottom end than the borer we took off and better cruise speed than the std cruise prop that came on the cub. Other than the price I wouldn't even consider going back to a borer.
 
I'm hoping to go constant speed on the pa14 I'm building, whirl wind makes a 84" thats only 42# , but the cost is a big factor. I don't fly far very often so cruise speed might not be worth the price for what I do.
 
Just out of curiosity, what is the physics behind long props being better for low speed and short props better for high speed. The F4U had a long prop and went very fast. Aren't longer props usually more efficient due to lower tip losses as a percentage of lift though they lose more to sound waves? How would that change with higher speeds? Is it because of the relative wind putting the tips too close to the speed of sound?
 
Take-off performance (on floats) with my new Catto, as opposed to my old Borer, was a wash. In the air, the Catto was about five mph faster. I like the nickel leading edge on the Catto, but I especially like the weight saving over the Borer. Losing 18 or 19 pounds off the nose is huge!
 
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I spoke with Sensenich yesterday on the availability of their ground adjustable composite prop. They told me they recently had been given FAA approval for production and have just started sending them out. I had elected to go with an O-360 in my Cub project primarily because of what appeared as a limited availability of good wide deck O-320 cores. I believe Lycoming made way more O-360's than O-320's. The forward CG issue was concerning but the word was Catto was working on certification and the fact it would be years before I assemble the pile of parts into an airplane I figured it would all come together at the same time. This Sensenich ground adjustable prop is better yet and approved for that O-360. If you want a Borer I would wait for the O-320 approval for the Sensenich, I suspect you'll see a lot of good deals on used Borer's. Similar to what's happening with the sale of used flaps. Since the p-stol flaps came out I'm noting about a 50% reduction in the asking price on a set of stock flaps.
I would also like to see an apple to apple performance comparison of the wood core Sensenich fixed pitch prop to a Borer. Anyone?
 
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Just look at the shape of the blades. A discussion of the aerodynamics involved would take a book. Let's just say it is obvious that a lot of educated thought went into this design. The "Borer" McCauley 1A175GM82xx is just an old rectangular aluminum prop which was built long before the highly sophisticated machinery and carbon fiber products were developed. This new Sensenich is going places.
2G0M8_82BG7-100x100.png
http://www.sensenich.com/shop/aircr...o-320-o-360-ground-adjustable-stol-propeller/
 
Has anyone done a good apple to apple performance comparison of a Borer prop to the Sensnich composite prop?
I gave one a short time ago on this site in another thread. I ran the sensenich on wheels, skis, and floats and then sold the borer. The pitch I settled on gets out like an 82-41 and cruises faster than the 8243. Much lighter and can be what ever you want it to by easily changing the pitch.
 
I gave one a short time ago on this site in another thread. I ran the sensenich on wheels, skis, and floats and then sold the borer. The pitch I settled on gets out like an 82-41 and cruises faster than the 8243. Much lighter and can be what ever you want it to by easily changing the pitch.

How are your cylinder head temps with the Sensenich ground adjustable?
 
I saw no difference in temps. I am running a 12" spinner. I am running an 0320 with 10-1 compression. On floats on an 85 deg. day my cyls. run around 380degs. That's the hottest I have seen with my CGR30-P monitoring all 4. I should probably note that my exp. uses a narrow J-3 style boot cowl with s. cub size cowls which gives me large gills which I think let out a lot of heat. I built it this way on purpose because I think it makes a difference in getting the hear out.
 
Sensenich is about 8 weeks out from time of order to delivery. I have two STC'd props for the 180 hp on order about a month out and only one is spoken for if anyone is interested. All I have been hearing is good. I ordered 4 for the O-320 with the STC expected in late May or early June.
 
How are your cylinder head temps with the Sensenich ground adjustable?
I keep hearing rumors that the CHTs were high on the Sensenich and not the Whirlwind but haven't been able to pin anyone down on this. The fact that the prop made it through the STC process tells me this wasn't an issue. Do you know more about it?
 
I keep hearing rumors that the CHTs were high on the Sensenich and not the Whirlwind but haven't been able to pin anyone down on this. The fact that the prop made it through the STC process tells me this wasn't an issue. Do you know more about it?
I guess the performance is the same between the sensenich and the newer WW blade design? The only difference is a slight cuff on the back of the WW and the indexing at the hub?

Will you be able to get the 82” blade on the O320 model?
 
I couldn’t find a weight on the 82inch adjustable sensenich, the spec sheet on their website shows the 72 inch prop at 12 lbs. I’m guessing 14 or so?


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I have the Sensenich new ground adjustable prop on my 0-235 powered Tcraft. The original style cause high CHT but this one has no problems. It pulls harder on take off at a lower rpm than the standard aluminum props. Haven’t tried it on floats yet but I bet it will be great. I would highly recommend the prop. Light and smooth.

Jim
 
I keep hearing rumors that the CHTs were high on the Sensenich and not the Whirlwind but haven't been able to pin anyone down on this. The fact that the prop made it through the STC process tells me this wasn't an issue. Do you know more about it?
Steve, I ran the whirlwind for over a year with no temp issues. Found it to be a great prop at 80". I kept it for a spare when I sold the Borer. The Sensenich is 82" which I think is just a tad better and is easier to change pitch. If they hold up, I won't be going back. Much smoother too.
 
I guess the performance is the same between the sensenich and the newer WW blade design? The only difference is a slight cuff on the back of the WW and the indexing at the hub?

Will you be able to get the 82” blade on the O320 model?
Yes, the blades are 82".

Weight of the propeller and spinner is 21 pounds.
 
I keep hearing rumors that the CHTs were high on the Sensenich and not the Whirlwind but haven't been able to pin anyone down on this. The fact that the prop made it through the STC process tells me this wasn't an issue. Do you know more about it?

I've spoken with a few people who had high CHT issues with them. Not sure if it's an isolated issue or if there's different blade profiles coming out now that help with that situation. Still considering bringing them in for sale but need to hear more positive news about the CHT issue.

Again, not saying it's a common issue, just that I've heard of issues. Want to hear more field reports about them.
 
I am very interested in any first hand reports on the Sensenich ground adjustable prop. Very curious about the cht issue. Thanks for your input Supercrow. Looking to possibly putting one on a O-360 cub.
Thanks
Mark
 
[FONT=&quot] Sat for hours grinding away at 80 mph with the engine screaming with no load on it behind a Borer prop. We only run on floats and skis. Picked up a Husky on wheels quite a few years back thinking it might be the answer to speed things up as our camp was 300 miles one way. When we flew it home on wheels it was as fast as everyone said. Couldn't wait to get it on floats. It lost a surprising amount of speed on floats. Just shy of 20 mph on Baumanns. Take off performance light or medium load was excellent. Loaded to super max handling was yikes a bit scary to say the least. Ours had that old bungee trim set up. Decided to switch back to a cub. Stuck with the 320 engine for the lower fuel burn but did a few legal mods to a new engine and put a constant speed MT reversing prop and a set of Aerocet floats on it. At 24 squared its runs a solid 95 knots by gps which I was quite surprised to see even though we have seen before the Aerocets are faster than 2000’s for some reason. Not that a man would but you can put 4 jerry cans of fuel in each float which gives you 76 gals total and with 2 people and gear it will get off no problem and handle way better than the Husky with the same payload and range. A light weight composite prop the same length as the borer with better shaping and the ability to dial it in to the max engine rpm out of the gate and stay there through the takeoff run and then coarsen it up for cruise is obviously the ultimate for float operations. I think people will see the cub isn't quite as high drag as one might think when they get running these newer props. [/FONT]
 
Before I say anything. I’m only a 200hr pilot. Soooo....
im in a pa-18a on a 150hp had a 80/44. I cruised mid 90’s and the plane did just fine. 31” bw. Plane flew everything I have asked it to and never took more than 400’ to get airborne. But it wrapped up slow, not a lot of pull behind it. Which really noticed when I got on skis.

im now sitting behind a 82/41 and it’s night and day difference. Static rpm is only about 20rmp higher (2370) but the pull off the block is way noticeable. Also it climbs much much better now. Couldn’t tell you numbers but I sure can tell it likes to climb where as before it like to circle stuff to gain altitude. No longer. Point it up and add power.

it looks like I lost less than 8mph off my cruise speed. Which I don’t care about.plus wind is always blowing anyway. Getting in the air is what makes a super cub a airplane. So the quicker and stronger I can get and stay airborne the better. I don’t use many developed strips where I am so pull off the ground is key.
 
My cub (320-B2B) made (I sold it.:-() 92 MPH with 42" Borer prop and 31" tires. In no wind trips, this was established by GPS many times. This was at 2400 RPM's. I hd previously an 82X41 borer, but when I put a new engine in I changed the pitch of the prop. Didn't really see any real change. I think the 3 most significant mods are 1) borer prop, 2) VG's, 3) bush wheels.
 
Peter,
That was an excellent post on the Cub with MT and Aerosets! Sounds like a very nice set up, The 95kts would certainly be sweet on a 300 mile trip��. Like you said from flying lots of different Cubs that belonged to various
Employers, I was used to seeing 80/85 mph in 150 /18's
Running 41/42 pitch Borers. My Cub I have now is a 160 with the Catto 84/36 Seaplane prop on it, Excellent performance out of the hole, but at 2450 on wheelskis or
Edo 2000's it's still a 90mph Cub. I think I might see 95kts
With a Whirlwind twisted up on 8:50's at 2600! Lol. Anyway thanks for that excellent report on the MT, coming from an "old pro"; With your experience that is some great info!IMG_20210222_093606665~2.jpg
 

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