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  #1  
Old 10-23-2012, 11:54 PM
AirbusPilot AirbusPilot is offline
 
Join Date: Jul 2007
Location: Santiago, Chile
Posts: 447
Default Hartzell propeller low pitch setting

Hi Folks,

I have a blended Hartzell propeller and I am trying to adjust low pitch setting, I have 2690 rpm at full static and on flight, so according to Hartzell manual if I turn one turn clockwise I should reduce 140-150 rpm, I tried first with half a turn, nothing happens, today again another half turn, but I still get 2690 static rpm, how much turn are you aplying to a stock blended stock Hartzell propeller with a Lycoming YIO-360-M1B to get 2650 RPM static???

Happy flying!!!

PD: I will try one more turn tomorrow
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Fernando Abasolo
Santiago Chile
SubSonex waiting for tailkit to arrive
Flying phase II RV-8 (SCSE) Serial Number 83290, Tail Number CC-AJC
Flying RV-8 (SCTB) Phase II 600 hours and counting since February 22nd 2010
Serial Number 82727, Tail Number CC-PXG
Lyc. IO-360, Hartzell Prop
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  #2  
Old 10-24-2012, 01:14 AM
Andy Hill's Avatar
Andy Hill Andy Hill is offline
 
Join Date: Dec 2005
Posts: 976
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Hi Fernando...

Just to be clear, there are 2 things controlling the minimum RPM of the Prop - the fine pitch setting, and the governor. The RPM will be limited to the more restrictive of these 2.

The fine pitch setting will govern RPM according to the airspeed of the prop, as a FP prop. So it is no use considering the setting at anything other than ~zero IAS. So your <<and on flight>> is not really relevant.

If you tie the aircraft down, and gently run it up to full power, the governor will limit RPM to whatever it is set to. You will not see the "low pitch" Max RPM unless you either adjust the governor to a much higher RPM, or "slam" the throttle open to try and beat the governor.

Personally, I hate running RVs at full power on the ground, with people on the tail or tied down. In the test flying I do, I check the RPMs:

Governor: In flight.. Rarely need adjusting from factory setting unless owner/builder has been "playing" with it

Prop Pitch stop: Either check on takeoff, or an aborted takeoff. Check all clear ahead, brakes off, and open throttle more aggressively than you normally would. Watch the RPM gauge closely and note the maximum you (briefly) see. This is the static RPM. Now adjust this ~1 turn a time and try again next flight. As you say, I would go for 2600-2650RPM unless you operate out of a VERY short strip.

From your post I suspect you are seeing the governor RPM?
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  #3  
Old 10-24-2012, 02:28 AM
kiwipete kiwipete is offline
 
Join Date: Oct 2007
Location: Birmingham United Kingdom
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Fernando

Both the hartzell prop's I have set up required at least 1 1/2 turns in from the factory setting.
As Andy pointed out the governor will most likely be controlling the speed unless you slam the throttle open.
The easiest way to set it up is now you know that the governor will hold 2690, keep winding the low pitch stop in until you get less than 2690 when doing a run up. You only need to go to full power for 1-2 seconds. Just make sure the plane is either has the tail tied or stick hard back with plenty of space in front of you if the brakes can't hold full power and it moves forward.

Peter
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  #4  
Old 10-24-2012, 06:09 AM
Walt's Avatar
Walt Walt is offline
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 6,340
Default

I like to monitor RPM (if you have peak recording tach it easy) on the takeoff run (minimum airspeed) rather than strap the aircraft down. It's not unusual in my experience to have to go 2-3 turns or more to get the drop.

Good for you for adjusting it, I think many folks forget or ignore this important adjustment.
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  #5  
Old 10-24-2012, 07:31 AM
AirbusPilot AirbusPilot is offline
 
Join Date: Jul 2007
Location: Santiago, Chile
Posts: 447
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Quote:
Originally Posted by Andy Hill View Post
Hi Fernando...

Just to be clear, there are 2 things controlling the minimum RPM of the Prop - the fine pitch setting, and the governor. The RPM will be limited to the more restrictive of these 2.

The fine pitch setting will govern RPM according to the airspeed of the prop, as a FP prop. So it is no use considering the setting at anything other than ~zero IAS. So your <<and on flight>> is not really relevant.

If you tie the aircraft down, and gently run it up to full power, the governor will limit RPM to whatever it is set to. You will not see the "low pitch" Max RPM unless you either adjust the governor to a much higher RPM, or "slam" the throttle open to try and beat the governor.

Personally, I hate running RVs at full power on the ground, with people on the tail or tied down. In the test flying I do, I check the RPMs:

Governor: In flight.. Rarely need adjusting from factory setting unless owner/builder has been "playing" with it

Prop Pitch stop: Either check on takeoff, or an aborted takeoff. Check all clear ahead, brakes off, and open throttle more aggressively than you normally would. Watch the RPM gauge closely and note the maximum you (briefly) see. This is the static RPM. Now adjust this ~1 turn a time and try again next flight. As you say, I would go for 2600-2650RPM unless you operate out of a VERY short strip.

From your post I suspect you are seeing the governor RPM?
Yes Andy, prop governor is holding down my RPM and not prop pitch stop, what really is worrying me is that I have turn a complete turn and I haven't be able to reduce the RPM, so probably prop from Hartzell are not set for RV, even we bought the prop from Van's. I have been flying the plane for 3 years and more than 300 hours and now I am thinking if my governor have failed RPM would go very high, maybe I wouldn't be able to maintain enought power to fly

I will keep turning that screw today till I setup the prop (I should did at the beginning, my fault)

Thanks for your reply!!!
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Fernando Abasolo
Santiago Chile
SubSonex waiting for tailkit to arrive
Flying phase II RV-8 (SCSE) Serial Number 83290, Tail Number CC-AJC
Flying RV-8 (SCTB) Phase II 600 hours and counting since February 22nd 2010
Serial Number 82727, Tail Number CC-PXG
Lyc. IO-360, Hartzell Prop
VAF #2056
EAA Member 774981
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  #6  
Old 10-24-2012, 07:33 AM
AirbusPilot AirbusPilot is offline
 
Join Date: Jul 2007
Location: Santiago, Chile
Posts: 447
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Quote:
Originally Posted by kiwipete View Post
Fernando

Both the hartzell prop's I have set up required at least 1 1/2 turns in from the factory setting.
As Andy pointed out the governor will most likely be controlling the speed unless you slam the throttle open.
The easiest way to set it up is now you know that the governor will hold 2690, keep winding the low pitch stop in until you get less than 2690 when doing a run up. You only need to go to full power for 1-2 seconds. Just make sure the plane is either has the tail tied or stick hard back with plenty of space in front of you if the brakes can't hold full power and it moves forward.

Peter
Probably you are right, I have turned 1 turn and nothing happens, a good start should be 1 and a half, turn. Today I will try another half a turn
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Fernando Abasolo
Santiago Chile
SubSonex waiting for tailkit to arrive
Flying phase II RV-8 (SCSE) Serial Number 83290, Tail Number CC-AJC
Flying RV-8 (SCTB) Phase II 600 hours and counting since February 22nd 2010
Serial Number 82727, Tail Number CC-PXG
Lyc. IO-360, Hartzell Prop
VAF #2056
EAA Member 774981
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  #7  
Old 10-24-2012, 07:34 AM
AirbusPilot AirbusPilot is offline
 
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Location: Santiago, Chile
Posts: 447
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Quote:
Originally Posted by Walt View Post
I like to monitor RPM (if you have peak recording tach it easy) on the takeoff run (minimum airspeed) rather than strap the aircraft down. It's not unusual in my experience to have to go 2-3 turns or more to get the drop.

Good for you for adjusting it, I think many folks forget or ignore this important adjustment.
I have been very lazy, I am adjusting now after 3 year and more than 300 hours. Better late than never
__________________
Fernando Abasolo
Santiago Chile
SubSonex waiting for tailkit to arrive
Flying phase II RV-8 (SCSE) Serial Number 83290, Tail Number CC-AJC
Flying RV-8 (SCTB) Phase II 600 hours and counting since February 22nd 2010
Serial Number 82727, Tail Number CC-PXG
Lyc. IO-360, Hartzell Prop
VAF #2056
EAA Member 774981
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  #8  
Old 10-24-2012, 08:47 AM
Noah's Avatar
Noah Noah is offline
 
Join Date: Jun 2007
Location: Rhode Island
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Quote:
Originally Posted by AirbusPilot View Post
I am trying to adjust low pitch setting...to get 2650 RPM static
Just curious- why are you trying to achieve 2650 rpm when 2700 is Hartzell's and Lycoming's limit? You will not damage the engine or prop if you momentarily reach (or even exceed) rpm by a little bit. Am I missing something?
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Last edited by Noah : 10-24-2012 at 08:58 AM.
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  #9  
Old 10-24-2012, 11:10 AM
aerhed aerhed is offline
 
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Location: Big Sandy, WY
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If you adjust the governor to 2650 static you will not be able to make 2700 in flight. Run-up to full throttle while tied, reduce RPM to desired setting with prop control and leave it there. Reduce throttle to idle, shut down and go look at the gap between the governor arm and the stop-screw. You can then turn the screw until it contacts the arm.
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  #10  
Old 10-24-2012, 11:12 AM
Andy Hill's Avatar
Andy Hill Andy Hill is offline
 
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Posts: 976
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Quote:
Just curious- why are you trying to achieve 2650 rpm when 2700 is Hartzell's and Lycoming's limit?
A good point

A fair number of reports on here of RPM surging i.e. poor Governor control e.g. on takeoff. Reducing the static RPM seems, anecdotally, to reduce this.

In essence, the governor takes a second or 2 to govern. If you set the static a little low, it ensures the governor has time to catch up

In addition, whilst you and I know you are allowed +10% (2970!) for 3s, your average engine monitor does not, and springs into life with all sorts of lights, noises predicting the end of the world

Quote:
so probably prop from Hartzell are not set for RV, even we bought the prop from Van's
It's not setting the prop "for RVs", but for the engine output. More HP = coarser pitch required @ 2700RPM.
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