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Hartzell propeller low pitch setting

AirbusPilot

Well Known Member
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
 
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?
 
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
 
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.
 
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:confused:

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

Thanks for your reply!!!
 
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:D
 
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:rolleyes:
 
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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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.
 
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 :eek:

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.
 
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

Peter you were absolutely right, today I turned 3/4 of a turn (plus one turn that I did before), now RPM are 2620 static and 2690 at 70 knots climbing. I am building a second RV-8 and I will turn 1 1/2 turn to begin.

Thanks for the advise:D
 
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.

I want the governor set to 2700 max rpm and lower prop pitch set to 2650 rpm static.
 
I'm a technical representative for Hartzell, so I thought perhaps I could be of some benefit.

When you are setting your low pitch stop, you want to set it about 50 RPM below max. RPM, so if you have a max RPM of 2700, set the low pitch for 2650 static. You will get 2700 (or perhaps more) shortly into you takeoff roll, as the prop ?unloads? and the airstream enters the prop.

I wrote a service letter a few years ago that discusses setting up your governor. Its available on our website if you follow this link:

http://www.hartzellprop.com/service_support.php?id=81

Find HC-SL-61-277 on the list and click on it to open or download it.
 
Wow

Our team of techies grows!

Welcome to VAF, Kevin, and thanks for the knowledge you bring to the table.

BTW, I did a first flight of an owner-built RV-10 and on takeoff, saw 3100 RPM!! I pulled the power back as quickly as I could (I believe the tips went supersonic) and landed.

What would be your recommended procedure to set the governor on a brand new engine/prop combination for a first flight?

Thanks,
 
The Service Letter addresses your O/S problem. Essentially, set your static RPM first. If you then if you O/S in flight, adjust your prop control to max RPM and land. Don't touch the prop control. Then adjust your max rpm screw on the governor so it just touches the stop, and adjust your prop control cable so you have full throw. That should do it. Read the SL before you do anything.
 
I'm a technical representative for Hartzell, so I thought perhaps I could be of some benefit.

When you are setting your low pitch stop, you want to set it about 50 RPM below max. RPM, so if you have a max RPM of 2700, set the low pitch for 2650 static. You will get 2700 (or perhaps more) shortly into you takeoff roll, as the prop ?unloads? and the airstream enters the prop.

I wrote a service letter a few years ago that discusses setting up your governor. Its available on our website if you follow this link:

http://www.hartzellprop.com/service_support.php?id=81

Find HC-SL-61-277 on the list and click on it to open or download it.

Thank you Kevin, as Pierre said is great to have you here.

Now my prop is set to 2620 static (low pitch set) and get to 2690-2700 during take off roll and flying, I am happy with that setup.

I think many here are setting the prop with 1 1/2 turn in, so I think Hartzell should sell the prop thought Van's with that setup to help builder.

Cheers,
 
Setting static RPM is a "normal" propeller installation task, even on certificated aircraft. On the Van's aircraft, the horsepower output of the engines can vary widely, so it is even more important to do a static RPM check, and adjust the low pitch stop as needed.
 
DGAC

Fernando,

This is a good thread. I'm still in Phase 1 and have to admit that I haven't recorded my exact takeoff RPM yet, except to say it's somewhere between 2650 and 2700. It will be on the checklist for my next flight.

I was also checking out your Maiden Fly album. Great pictures. I was impressed with the imposing size of the DGAC guy, who I assume was conducting your airworthiness inspection. He looked a little intimidating. I guess if you could get through that okay, the first flight would be a cinch:)

Thanks for posting the link to your albums.
 
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Another data point

Just another data point for anyone else looking at this thread. I have a Hartzell HC-C2YR-1BFP/F7497 (beautiful prop, by the way) that I bought from Van's and I needed 3.5 turns in to get the low pitch setting to stay at 2700 RPM during the climb out. I have a TMX IO-360 that is supposedly rated at 180 HP, but I think it's giving me a bit more.

My static during ground testing with the tail tied down was right at 2700 before turning the fine pitch stop - I kept seeing more during the takeoff rolls and climb out, so gradually added turns until now, I think I have it just about perfect.
 
I helped a friend go through this on his IO-540 this week. I don't remember how many turns he had to take it, but I think it was more than 2. My advice is maybe contrary to what others may feel, but I think if you've never adjusted it before, you should not just nibble at the adjustment. Take it at least a full turn and then test. Maybe 2 full turns. It won't take too long then to see when you actually start to be prop stop limited vs governor limited. Then once you see that your hard stops are doing the job, you can easily just estimate how many turns to go back the other way to get it near where you want it.

I did learn in this thread one valuable tip...that 50 RPM low is what you're looking for. I had guessed that it was 30-40, but it's nice to hear in this thread that 50 is where to shoot for. Right now I have to drop mine about 30 RPM, so that will be my next mini project.
 
... My advice is maybe contrary to what others may feel, but I think if you've never adjusted it before, you should not just nibble at the adjustment. Take it at least a full turn and then test. Maybe 2 full turns. ...
I agree - I believe it took me 4 iterations to get it where it is now, and I probably need one more. Not a huge issue - it takes about 2 mins to get the spinner off, but I could have gone 4 turns at first and probably been very close. I read from others that they needed 1.5, which is where I started, but it seems that not all props are delivered from the factory with exactly the same fine pitch setting.
 
If your low pitch stop is set to limit your climb out RPM, then what static RPM are you seeing?
 
Fine Pitch Adjustment

Good for you for adjusting it, I think many folks forget or ignore this important adjustment.

I agree! I think many folks miss the fact that proper (or improper) propeller hub fine-pitch adjustment is a significant safety issue. Limiting how fine the propeller pitch can go with no oil pressure helps reduce windmilling propeller drag in an engine out with loss of oil pressure situation.

I'm convinced that most people don't adjust it. I prefer to set 2650 static RPM @ sea level as the fine-pitch limit. It will come up to 2700 almost immediately on the takeoff roll as the plane starts rolling forward.

Skylor
 
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I finished the adjustment on mine yesterday. My governor was previously set to run about 2740rpm, out of the box. The prop RPM on the ground was about 2700 rpm static, but on takeoff I could see 2720-2740 if I left the lever full forward.

I turned it a little less than 1/4 turn of the hex screw, in.

Now it's 2660 rpm static on the ground, and was a perfect 2700 on takeoff. I did see 2710 for a brief second. Since I didn't adjust my governor down from 2740, there is a slight amount of extra oil pressure available to try to push the pitch, which should give a little margin if oil temp or pressure fluctuates a little and would have caused me to not reach 2700.

The big relief is that I'll not have to worry about an extreme overspeed event from here on out.
 
I finished the adjustment on mine yesterday. My governor was previously set to run about 2740rpm, out of the box. The prop RPM on the ground was about 2700 rpm static, but on takeoff I could see 2720-2740 if I left the lever full forward.

I turned it a little less than 1/4 turn of the hex screw, in.

Now it's 2660 rpm static on the ground, and was a perfect 2700 on takeoff. I did see 2710 for a brief second. Since I didn't adjust my governor down from 2740, there is a slight amount of extra oil pressure available to try to push the pitch, which should give a little margin if oil temp or pressure fluctuates a little and would have caused me to not reach 2700.

The big relief is that I'll not have to worry about an extreme overspeed event from here on out.
I’m confused, Tim. Your first paragraph implied, I thought, that the mechanical stop limited static rpm to 2700 rpm, while your governor would limit rpm to 2740 with significant forward motion. How could you make a single adjustment and get both of these numbers lower? I also don’t understand the last sentence; if your governor fails (or you run out of oil) at cruise speed there will be a significant overspeed.
 
Sorry about that. Here's a better run-down.

Previously I had a P-860-3 governors on my old IO-540. The new IO-540 required a P-860-5. My old governor limited my prop to 2700 rpm. But, that was governor limited. My hard stops were much higher. I'm not sure what the limit was, because I wasn't interested in pushing it there. I know it was over 2780 at one point. I recently put on a new engine and within the first 8 hours put on a new governor also, just because it was a different drive ratio between the 2 engines, and mine was overdue for service. When I put the new governor on, I was surprised that it went higher. So I previously adjusted the new governor down a little.

On my last test after turning the prop adjustment in 1 full turn (which really is back to where I had originally had it set many years ago) I could get static RPM on the ground of 2700 or so, and could get 2740 in flight. This was a week or two ago.

So yesterday I turned in the prop adjustment a little less than 1/4 turn, because that's about 40 RPM drop. Now I get 2660 RPM static, and 2700 in flight.

So at this point, my governor can call for more RPM than that, but my hard stops won't let it go any finer pitch than the redline of 2700 RPM. So I'm hard stop limited. The governor will allow it to go a little higher, but the stops prevent it.
I wanted the governor slightly higher, so that variations in viscosity or oil pressure shouldn't cause much of a reduction in RPM. Perhaps simply flying in cold air may change things in my cold climate, but I'll see this winter.

So yes, the mechanical stop is limiting it now to 2660 static, which translates to 2700 in flight. I didn't make 2 adjustments yesterday, just the prop.

At any rate, the important thing is, I can't have a significant overspeed anymore, since it's hard stop limited.

The real finishing touches, if I choose to do it, would be to turn my governor set screw in until I can no longer get 2700 RPM. Once I get to where I see something like 2680 or so, I could then back the screw out 1 turn which I think is 25 RPM. That would put me just over 2700 RPM in the governor capability. Or maybe 1.25 turns just for a little extra pressure margin.

BTW: These are MT Governors...others will have different adjustment amounts or methods.
 
Tim, that’s not the way things work. The mechanical stop limits the pitch, not the rpm. If the prop stayed against the hard stop for some reason, it would act just like a fixed pitch prop. As the forward speed increases, the angle of attack on the prop goes down, and the rpms then increase. Look at the FP props - typically 2300 static, 2700 or more cruise (full throttle). You must have bumped the governor adjustment down to 2700. And, if the governor fails in cruise, the hard stop only limits the pitch to a pretty fine angle - and pretty high rpm (at power).
 
To be clear, yes, you’re correct, but limiting pitch also
Limits the ultimate RPM that you can make. So by changing the blade angle of finest pitch you’re also changing max static RPM.
 
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