Idle speed setting

Discussion of the Aerovee kit engine.

Idle speed setting

Postby Bryan Cotton » Wed Dec 07, 2022 2:11 pm

Hay all,
The manual specifies 800-900 rpm. I have a hard time getting it set that accurately. The problem is that I've had it too high a few times and that isn't good for landing. My current idle stop is set so the engine won't quit, but I need to add a little throttle to get the speed right. Anybody else having this issue? What are your thoughts on my setup?
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
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Location: C77

Re: Idle speed setting

Postby Area 51% » Wed Dec 07, 2022 3:42 pm

Bryan Cotton wrote: My current idle stop is set so the engine won't quit,


Is that idle stop setting above the 800-900 rpm specification? If so, why do you have to add throttle to "get the speed right"?

If that idle stop setting is below the 800-900 rpm specification, I don't see the problem.

What am I missing?

Rattling around in the box with the rest of the rocks here @Area 51%
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Re: Idle speed setting

Postby Bryan Cotton » Wed Dec 07, 2022 7:31 pm

My idle speed at the stop is too low for my MFD to read. So I have to bump it up. Idle stop speed too high was a previous iteration.
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
User avatar
Bryan Cotton
 
Posts: 5035
Joined: Mon Jul 01, 2013 9:54 pm
Location: C77

Re: Idle speed setting

Postby pfhoeycfi » Thu Dec 08, 2022 8:40 am

Getting the idle speed right is the only thing holding me back from the first flight. After initial start w the trottle at the idle stop I can get the 800 to 900. Once the engine runs for a few minutes and gets warms I'm at 1100 to 1200 at the idle stop. Getting the right balance has been difficult.
Peter Hoey
SEL Pvt, Comm Glider, CFIG, Pawnee & L19 Towpilot
Philadelphia Glider Council
Sonex B SNB0021, N561PH, Taildragger, Aerovee Turbo, MGL MX1, First flight Dec 18, 2022
Also built Sonerai IIL N86PH
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Re: Idle speed setting

Postby Bryan Cotton » Thu Dec 08, 2022 8:55 am

I had a similar high idle on my first few flights. It was ok but we all know you use more runway. Yesterday we had marginal VFR and I spent an hour and a half in the pattern. Idle stop too low, but engine doesn't quit on the ground when warm. Seems good. Once I'm done slowing down I just tweak it up off the stop.

It's really cool to go out and beat up the pattern like I was flying a Pawnee or something. Took a while to get here. You will too. Good luck on your first flight!
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
User avatar
Bryan Cotton
 
Posts: 5035
Joined: Mon Jul 01, 2013 9:54 pm
Location: C77

Re: Idle speed setting

Postby Bryan Cotton » Thu Dec 08, 2022 12:06 pm

One other thought - a slightly high idle on my first flight was not a big issue for me. I had 3773' of runway, and the Waiex has plenty of sink on the backside of the airspeed curve, even in ground effect. Would have been unnerving to have it quit.
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
User avatar
Bryan Cotton
 
Posts: 5035
Joined: Mon Jul 01, 2013 9:54 pm
Location: C77

Re: Idle speed setting

Postby Arjay » Thu Dec 08, 2022 4:55 pm

My Aerovee with Rotec tbi runs just fine idling at about 1000rpm. Below that it feels like it wants to stop running. I have to lean it out for best smooth running at all rpm’s. I get 3200 rpm at takeoff, increasing to 3240 just after liftoff.

Ron, legacy Sonex tailwheel.
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Re: Idle speed setting

Postby pfhoeycfi » Thu Dec 08, 2022 7:24 pm

Bryan Cotton wrote:It's really cool to go out and beat up the pattern like I was flying a Pawnee or something. Took a while to get here. You will too. Good luck on your first flight!


One of the endearing attributes of the club farm equipment (Pawnees) is that if you lose power its easy to determine where you are going to land. Simply visualize an imaginary line drawn from your eyes past your feet to the ground. You can never be too high. But yes they are fun to fly.
Peter Hoey
SEL Pvt, Comm Glider, CFIG, Pawnee & L19 Towpilot
Philadelphia Glider Council
Sonex B SNB0021, N561PH, Taildragger, Aerovee Turbo, MGL MX1, First flight Dec 18, 2022
Also built Sonerai IIL N86PH
pfhoeycfi
 
Posts: 378
Joined: Wed Jun 28, 2017 3:45 pm

Re: Idle speed setting

Postby Bryan Cotton » Thu Dec 08, 2022 11:56 pm

pfhoeycfi wrote:One of the endearing attributes of the club farm equipment (Pawnees) is that if you lose power its easy to determine where you are going to land. Simply visualize an imaginary line drawn from your eyes past your feet to the ground. You can never be too high. But yes they are fun to fly.


Yep, never too high! On a day smooth enough to run to Vne it is amazing how much green and how little blue is in your forward view.
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
User avatar
Bryan Cotton
 
Posts: 5035
Joined: Mon Jul 01, 2013 9:54 pm
Location: C77


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