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Anyone have an E-Props and 912iS?

R

RV8AHopeful

Member
Does anyone have a 912iS engine paired with an E-Props propeller? If so, have you encountered any issues? Specifically any problems with fluctuating airspeed?
 
I have a E-Prop DUR-3-175-C4-T awaiting install on my RV-12iS and am curious about your ‘fluctuating airspeed” question.

Is this question based on personal experience or have you heard of issues that I should consider prior to mod?

Thanks,
 
Invicto89 said:
I have a E-Prop DUR-3-175-C4-T awaiting install on my RV-12iS and am curious about your ‘fluctuating airspeed” question.

Is this question based on personal experience or have you heard of issues that I should consider prior to mod?

Thanks,
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Well, I don't have any evidence that there's anything wrong with the prop. I have a 912iS paired with E-Props DUR-3-175-C4-T and was thoroughly impressed with it at first over the Sensenich it replaced, but about 15 flight hours after I installed it I developed a problem with reduced airspeed and seem to have ruled out everything except for the prop and just wonder if maybe it’s doing something funny due to some manufacturing defect that only showed itself after 15 hours of flying. It's unlikely, but possible, and that's why I'm asking. I also encountered increase spiraling slipstream when I installed the E-Props, which led to more right rudder required and more rudder trim to keep coordinated in cruise.

Performance wise though, it was amazing at first. I saw about 30% increase in climb rate with no reduction in cruise speed. But then about 15 flight hours later, suddenly a problem where both the climb rate and cruise speed has significantly decreased. But literally everything that can be tested has been tested with both the engine performance, ASI/pitot-static, and checking the airframe for drag, and absolutely everything checks out so now I can't help but think about the prop since the problem started just 15 hours after it was installed.
 
I would first contact Anne Lavrand and tell her whats happening. But I figure out you checked torque and pitch, so perhaps you have a prop balance issue?
There are a few e-props flying here and none with any problems and a lot more flying hours than yours. Everything come balanced, even the spinner... but it did happened once that they modified the spinner and affected so much that it was noticeable and they have to add up some washers in the bolts to solve it.
 
Have you looked at the data history of the engine operation?
If the engine is still running at the same RPM in cruise and climb as it was right after you first installed it, then I don’t see it being possible that the issue is caused by the propeller.
 
rvbuilder2002 said:
Have you looked at the data history of the engine operation?
If the engine is still running at the same RPM in cruise and climb as it was right after you first installed it, then I don’t see it being possible that the issue is caused by the propeller.
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It's too far back now and that engine data history is gone.
 
Dabb said:
I would first contact Anne Lavrand and tell her whats happening. But I figure out you checked torque and pitch, so perhaps you have a prop balance issue?
There are a few e-props flying here and none with any problems and a lot more flying hours than yours. Everything come balanced, even the spinner... but it did happened once that they modified the spinner and affected so much that it was noticeable and they have to add up some washers in the bolts to solve it.
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I'm told it's impossible to have a prop balance issue with these because of how they are made? The bolts were all torqued to spec and then retorqued as recommended, and the pitch on all 3 blades are still exactly what they were the day they were installed down to the tenth... exactly 22.2.
 
RV8AHopeful said:
I'm told it's impossible to have a prop balance issue with these because of how they are made? The bolts were all torqued to spec and then retorqued as recommended, and the pitch on all 3 blades are still exactly what they were the day they were installed down to the tenth... exactly 22.2.
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Yes, the whole assembly comes balanced. Thats why you have colours to identify which part goes where and replicate how it was assembled when balanced at factory. BUT... if you modified the spinner or any part for some reason, it might happen. I just made the comment for that. If anything was modified, all things equal and you have a measurable drop in performance. I would check the engine as rvbuilder2002 said.
 
Dabb said:
Yes, the whole assembly comes balanced. Thats why you have colours to identify which part goes where and replicate how it was assembled when balanced at factory. BUT... if you modified the spinner or any part for some reason, it might happen. I just made the comment for that. If anything was modified, all things equal and you have a measurable drop in performance. I would check the engine as rvbuilder2002 said.
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Only thing modified was the spinner cone was painted. But it was painted with instructions for as light a coat as possible. Also, everything was fine for several hours after it was painted. I would think if the paint caused a balancing issue, it would have been evident immediately and not 10+ hours later?
 
Shot in the dark...don't know if possible or likely but could this be a symptom of the gearbox overload clutch slipping?
 
bbaggerman said:
Normally the amount of torque to turn the overload clutch is huge... 442 to 590 ft-lbs from my notes.
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Yes, but if clutch is going bad how much less does it take. The original question stands, can a failing slipping overload clutch present this way?
 
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