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E-prop installation in the Southeast?

scottmillhouse

scottmillhouse

Well Known Member
Recent posts represent switching to an E-prop adds near constant speed performance to a RV-12. Have always wanted to swap to a CS once Mosaic kicks in. This prop appears to perform similarity. Anyone have one installed in the Southeast that I can check out?

Never mind. Got sold on the prop and have one on order. I will stride to do an apples to apples comparison and be a resource for others considering the swap.
 
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Amadeus said:
Looking forward to hearing not only about the performance improvement but also the steps required to make the change!
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For starters I found out Evolution Aircraft out of Zephyrhills FL Larry Mednick has installed a number on RV-12s, is a distributor and is very knowledgeable on the props including the stock ones. I elected to get the model without the pitot tube in the spinner since I planned to move the source to the wing anyway. That eliminates even more weight and is less complex and costly. $2275 delivered rather than the 2700+ euros on the company site. In a couple of weeks I should have the new prop. I'll stride to benchmark my current setup and compare with similar conditions.
 
scottmillhouse said:
For starters I found out Evolution Aircraft out of Zephyrhills FL Larry Mednick has installed a number on RV-12s, is a distributor and is very knowledgeable on the props including the stock ones. I elected to get the model without the pitot tube in the spinner since I planned to move the source to the wing anyway. That eliminates even more weight and is less complex and costly. $2275 delivered rather than the 2700+ euros on the company site. In a couple of weeks I should have the new prop. I'll stride to benchmark my current setup and compare with similar conditions.
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Did you order through Evolution (Larry), or the companies website?
 
scottmillhouse said:
Larry, just told me it should ship end of next week with receipt the following week. I’ll have to get going moving my pitot so I can do comparison testing.
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I am looking forward to hearing your test results.
I am almost ready to pull the trigger after all I have been reading. I think am going to talk to Larry.
 
Just finished pitot and AOA movement to the wing mast. Note a service loop and disconnects at wing root for wing removal.

Hope to do baseline testing of old prop Monday. New E-prop gets delivered Monday so installation and comparative testing will follow.
 

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scottmillhouse said:
Just finished pitot and AOA movement to the wing mast. Note a service loop and disconnects at wing root for wing removal.

Hope to do baseline testing of old prop Monday. New E-prop gets delivered Monday so installation and comparative testing will follow.
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I am eagerly awaiting your results. Especially since my prop hub now has to be disassembled and inspected every 50 hours per Sensenich...
 
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Did testing of old and new. For some reason the Dynon did not keep most of Monday file, may have exceeded storage size so my data is not as comprehensive as I hoped. For that what I provided is from my notes and FlightAware recordings. I provided average climb rates to 7500' for all tests. For both props it was consistent until about 6000' and then dropped about 100fpm. From previous testing I noted climb dropped another 100fpm by 10,000'. I saw no value going past 7500' especially with my sinus congestion. The E-Prop pitch level tool became erratic and I had to use an alternative for my last trial. Prop is still too coarse. Need to get RPM up higher in climbs and drop the top speed. Prop is very smooth and does remarkably well at such low engine RPMs. More to follow....

prop presentation.jpg
 

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More notes: On plane flights starting with 3/4 fuel, solo 170# pilot, take off weight approximately 1030# moment 86633 and arm 84.11 for initial and somewhat less for the E-Prop. The plane will be re-weighted for a new W&B. Pictures show configuration with the pitot moved to wing. Also note that my plane has full wheel pants and is painted. By take off feel at TO trim set it feels that CG is shifted slightly aft so the trim mark may move slightly forward.

I had an even 3/16" gap between spinner and cowl which is now 3/8". I guess they were off a little on geometry. Not noticeable with black carbon fiber spinner finish. Was planning on painting orange but now thinking natural.

An interesting characteristic is a pause and grab during rolling up for take off. You start moving and it appears to slow acceleration probably at around 10 knots and then grabs and accelerates briskly (more than stock) but with the pause the take off distance appears about the same.

It definitely is pitched too coarse but it was kind of fun seeing TAS over 130 knots (and Dynon Betty telling me to slow down) in the 5500+ rpm range. It appears to have less drag so descents are at a faster speed. Prop is very smooth being dynamically balanced during manufacture. The motor is lugging in climb but is still doing about 1000fpm. Once optimized I expect about 1200fpm and a top speed of about 122. An improvement over stock. It does appear to defy traditional prop physics. More to follow.....
 
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What spacer did you use? My spinner/cowling gap is smaller after the e-prop install with the -15mm spacer (gap 1/8"). Looks like you have the -10 spacer?
 
These seem like very impressive numbers! If I can find a nice RV12is for sale, it's a mod I'll definitely consider
 
scottmillhouse said:
Need to get RPM up higher in climbs and drop the top speed.
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In your numbers it appears that with the eProp manifold pressures are higher for similar RPM. Is this a safe variance long-term for the 912 engine? It seems that it must be or the FADEC wouldn't allow.
scottmillhouse said:
Prop is very smooth being dynamically balanced during manufacture.
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This HAS to help with the -12iS radiator issue!
 
To answer questions gap is with spacer provided. Larry said he’d provide one to reduce gap if I wanted but I’m keeping to ease lower cowl removal. Yes manifold pressure is about 1” higher so the motor is working harder for that RPM as expected with more bite to the prop and higher speed. This is the ULS, carb motor on a legacy RV-12 and not the is. Will repitch to optimum next week once I have the new pitch level tool.
 
I'm currently in process of building a rv12is. I'm very interested in the e-prop. Just wondering what it would take to get Van's to consider the e-prop as a prop option for us in-progress elsa builders?
 
Cobra427man said:
I'm currently in process of building a rv12is. I'm very interested in the e-prop. Just wondering what it would take to get Van's to consider the e-prop as a prop option for us in-progress elsa builders?
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You never know until you ask. But I doubt that they will approve anything without proper testing. And that would mean an added expense for them.
 
Amadeus said:
In your numbers it appears that with the eProp manifold pressures are higher for similar RPM. Is this a safe variance long-term for the 912 engine? It seems that it must be or the FADEC wouldn't allow.
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The higher MAP seems to be ok, and is something I'm encouraged to see verified in this exercise. We can refer to SL-912-016 for guidance on MAP/RPM, at least with respect to detonation which would be the primary concern here.

I'd like to see MAP for the climb portions if available.

Screenshot 2024-10-25 at 7.15.18 AM.png
 
Worst by data review appeared to be 29.5 MP at 5182 RPM for last test flight using 93 octane ethanol free unleaded immediately after lift off (RON98) so I think we are good. I tried to keep RPM above 5200 which made airspeed to above 90 knots. I'd like to drop that down to closer to 70 at 5200 if possible.
 
Couple of thoughts here.
First, have you noticed any change in your CHTs or Oil Temps with the E-Prop? Cooler or Hotter in the climb to 7500'!
Second, Maybe treat it like a Hybrid Constant Speed Prop!
Reduce the Pitch so you get 5750 RPM on climb out. Say a static of 5600 RPM!
After takeoff at the 5 min mark reduce to a climb power setting of 5500 RPM which would be around
5000' PA, continue to 7500' PA level and accelerate, see what that prop will do!
I would think that there is a point where it will only go so fast. But it is intriguing to see what the Max performance with the correct pitch setting will be.

On another note could you start a new thread about how you mounted the pitot tube in your wing.
Thanks
 
Looking forward to more data. I have over 500 hours on my stock Sensenich (all Dynon data downloaded & kept), and I'm considering the E-Prop 3 blade for my ULS. My home airport is 100 MSL, and I'm pitched to 5450 @ 75 knots for continuous WOT climb. That's too fine for fast cruising, and too course for best takeoff. It's the compromise I made years ago, so I have lots of data.
 
Jetguy said:
Couple of thoughts here.
First, have you noticed any change in your CHTs or Oil Temps with the E-Prop? Cooler or Hotter in the climb to 7500'!
Second, Maybe treat it like a Hybrid Constant Speed Prop!
Reduce the Pitch so you get 5750 RPM on climb out. Say a static of 5600 RPM!
After takeoff at the 5 min mark reduce to a climb power setting of 5500 RPM which would be around
5000' PA, continue to 7500' PA level and accelerate, see what that prop will do!
I would think that there is a point where it will only go so fast. But it is intriguing to see what the Max performance with the correct pitch setting will be.

On another note could you start a new thread about how you mounted the pitot tube in your wing.
Thanks
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Already several threads on the RV-12 forum for installing a pitot tube in the wing. One example:

https://vansairforce.net/threads/heated-pitot-for-rv-12is.213352/#post-1660627

John Salak
RV-12 N896HS
 
Here is about as good as I could get for a direct prop comparison for similar days. As indicated in another thread I spent a lot of time optimizing my Sensenich from Vans 71.4 degree pitch to 70.0 to get my target mix of climb rate and additional speed. After false starts with a defective prop level, pitched way too course, 25 degrees on the E-prop approximates the Sensenich and my objectives. In a nutshell this prop at this pitch gives an increase of 200 fpm climb and 3 knots in top speed and cruise at about an inch increase in engine manifold pressure. No measurable changes in temperatures. My target indicated climb speed of 75 knots dropped the RPM down lower than maximum power output on both props so climb rate may increase at a higher climb speed but I did not test for optimum climb. Other E-prop pitches showed as much as 10 knot increase in top speed with reasonable climb rates but the engine was lugging at too high MP for engine health. Prior tests with corrected prop pitch are attached. Could not attach an excel so substituted an image.

The prop is very smooth with less drag so your descent and low MP speed increases. It also appears less responsive to turbulence. It does weigh less. I'm redoing my W&B for a direct comparison that I'll share when complete. I know a number of RV-12 drivers interested in changing props, especially with the recent prop SB. I've talked to Larry at Evolution and he will offer a special rate of $2500 total delivered with the new prop gauge and spinner included for Vans through the prop pitot until 1 January for the group. Cheaper if you relocate the pitot to the wing. About a $500 savings. Just mention scottmillhouse on order to get special rate. (I gain nothing, just interested in sharing a good deal)
prop comp.jpg
 

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Did a new W&B with the E-prop with supplies/spares as I typically fly solo. Effect is that it is easier to get an aft CG. Weight is reduced 2.5#, 6.5# to nosewheel. Only thing added since original W&B is a Koger sun shade. Originally solo with full fuel I could only have 40# of baggage before aft CG, with the prop change it has been reduced to only 26#.

View attachment prop CG calcs..jpg
 
Now that I did a new W&B I can report that the E-prop flight was at a weight of 1031.5#, 86745 moment and 84.1 arm, 170# pilot and 3/4 fuel. Also I posted average climb rate to 7500’ but should note that this prop is better at lower altitudes in climb actually 1100-1200 fpm with a significant drop (more than stock prop) above 5000’. It gets a better bite at lower altitudes. Here is my typical test flight plan. Used autopilot with altitude hold and ground track to establish test speed and rpm at altitudes.
IMG_1887.png
 
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Just received my new e-prop yesterday. Thanks Scott for all the info and letting us know about Larry's deal. Unfortunately for me, I missed out on the special price by two weeks, but I am looking forward to installing it.
 
To follow up after a few more flights I can report some more observations. Similarity loaded but OAT about 65 in flight, after initial lift off using 85-90 IAS I see about 1100 fpm climb. At 3200’ 123 KTAS at 5500 rpm and 120KTAS at cruise. Plane now has it’s side stripes and is considered finished.
 

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Just ordered an E-Prop for my -12 with the ULS. Boy am I looking forward to smoother shutdowns. I’m not even really in it for the performance increase, I just want to treat my gearbox better. What location did you use to zero out the protractor?
 
I used the spinner back plate. Larry’s video show using an engine bracket but I did not think it was repeatable for multiple sessions. The information with the prop says use 27 degrees to start. I found out Larry has been using 26. I found that too coarse and used 25 to keep RPM up above 5200 in full power climb to avoid detonation
 
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