Need prop governor advice.

[Lood]

I'm having minor issues with my prop governor and because I am rather skeptic when it comes to overhauled or reconditioned things on my engine, I think I will just replace the governor with a new one.

Should I go with PCU or stay with Hartzell?

 

I would appreciate some opinions and advice. Thanks in advance!

[Lood]

I would also like some pointers on where I can go to for a new RPM control cable. The part # is: 660189-5, but I can seem to find anything in this regard on the web, bar an old SB.

[Cody Stallings]

What is the Minor issue?

[aaronk25]

Overhaul parts no good? Ask lycoming why the brand new cam they gave me failed in 2 years and 400 hours and how the re-manufactured cams seem to last.

[Lood]

I'll try and keep this as short as possible:

For quite some time now, I've not seen red line rpm on take off, but rather 2560 rpm. This would happen mostly on the first flight of the day. On consecutive flights, full rpm would be available on take off. I managed this, but I can assure you, when fully loaded, or at hot and high conditions, the lack of power could actually be felt. This reduced rpm would last for about 5 minutes, after which the rpm would slowly increase to reach 2700 rpm. This was not a limit screw issue, but rather an issue with the governor itself. On a flight earlier this year, taking kids back to school, I suddenly lost about 100 rpm, uncommanded.

 

My AME suggested we send the governor in to have it inspected. R2700.00 later, it came back - fixed. Apparently, the relieve valve was stuck. It was installed and worked perfectly well - for about 12 hours. Then it started repeating the reduced rpm on take off issue.

 

On my last two flights, which happened on the same day, the following was observed:

 

First flight:(return flight)

Engine oil level was right on 6 on the dipstick. On take off, I got only 2590 rpm and after 5 minutes, 2700 rpm. During this flight, the rpm was fluctuating continuously, between 2430 - 2480 rpm.
On the return flight, I got full rpm on take off. I set cruise power as usual, WOT, 2450rpm, 75 deg ROP. After clearing the TMA, I started a short 500' climb - from 6000' to 6500'. During this climb, the rpm started increasing, all by itself, from 2450 to 2550 rpm. I dialed it back to 2450 after which it continuously fluctuated between 2390 to 2470 rpm.

On both these flights my oil pressure also fluctuated continuously, between 58 - 66 psi.

 

Second flight, same day:(also a return flight)

I added 1 quart of oil. On take off for both there and back, I got 2700 rpm, oil psi was rock steady on 68 psi and rpm was rock steady on 2450 rpm???

 

I'm not sure if this indicates that my engine doesn't like the oil level to drop below 6? Regardless, there is a problem with the governor. I have already spend almost 25% of a new one's price and I'm certainly not going to have it fixed again, just to have to fix it - again. I always fly my engine until the oil level drops to about 5.5, before I add oil and in the past, this didn't have an effect.

 

During the most recent repair of the governor, the shop did remark the following: "There is evidence, that metal had passed through the governor, at some earlier stage."

They didn't find anything, apart from the relieve valve being sticky, but apparently, scratch?

 

I look forward to your replies.

[carusoam]

Looking at prices... Many choices, all under 2AMU...

http://www.aircraftspruce.com/menus/ap/prop_governors.html

You might search PCU5000. I had difficulty with their website this morning...

The govenor is an oil gear pump that is controlled by a pair of fly-weights. The weights operate a valve to adjust pressure to the prop.

Lots of opportunity for wear.

Ours are supposed to fail and set to max RPM, unless you fly a Missile....

Hope that helps,

-a-

[carqwik]

Are you sure it's the prop governor and not the tach that is failing?  I had an EI tach that was showing similar RPM fluctuations and had my prop governor OH'd....turns out, the problem was in the tach wiring somewhere and for reasons still unknown while looking for a loose connection, the problem rectified itself. 

 

Prior to that, the rpm would suddenly move around by about +/- 150 to 200 rpm on the read out yet I didn't hear a difference...unless I fiddled with the prop lever to "chase" the change.  So I might suggest doing an RPM check with one of those strobe devices to see if the problem is in the governor or in the tach itself.

[HRM]

I'm having minor issues with my prop governor and because I am rather skeptic when it comes to overhauled or reconditioned things on my engine, I think I will just replace the governor with a new one.

Should I go with PCU or stay with Hartzell?

 

I would appreciate some opinions and advice. Thanks in advance!

 

I think you may be a bit "once burned, twice cautious" here.

 

Reconditioned anything is more dependent on the human factor than machine.

 

A good shop will do as good a job as the factory.

 

Any part can fail at any time--new or reconditioned.

 

I spend my time and energy checking references, I've saved a lot that way.

[urbanti]

Recently I started getting weird engine rpm behavior, checked prop rpm with an optical checker and the old governor was worn out.

The shop that my mechanic sent it out to said it was really shot and that parts are difficult to get for the oem governor, and they weren't sure how long a rebuild would last.

I purchased a new aftermarket governor. Now prop control functions fine, and the new governor maintains the correct max rpm below redline on climbout now.

best

Tim

[Cody Stallings]

Sounds a lot like the issues I had with a Hartzell H-1(Hamilton Std).

Sometimes it was 150 RPM under T/Off RPM, Sometimes it wasn't.

Last flight with it consisted of the propeller trying to fix pitch an runaway in RPM.

With the Propeller control all the way aft, 2500 was as low as it would go.

A McCauley Gov fixed all my issues, everything has been working great, an it was an O/H unit.

The Hartzell H-1 is a good Gov, it's been around for yrs. Many Many yrs, Most round engines from the WWII era have one.

Over many O/H's Fits an Clearances become comprimised.

Back to the newer more Modern designs.

The McCauley an PCU5 seem to be holding up really well, I have heard very few complaints about them after installation.

[Tommy]

I would, definitely check it against an optical tach before pulling anything major like this! Can you actually feel the prop changing rpm when the fluctuation happens?

[urbanti]

The governor I bought was an Aero Technologies PCU5000

It was recommended as a drop in replacement for the oem governor, and seems to work fine.

The one idiosyncrasy of the new governor is that you have to perform your prop control check at 1,600 rpm rather than 1,500 rpm.

Any questions feel free,

Tim

[Guest]

Was there a weight savings with the new one?

Clarence

[Andy95W]

Was there a weight savings with the new one?

Clarence

What about a TAS increase?

[N601RX]

Was there a weight savings with the new one?

Clarence

I purchased the used PCU 5000 listed on here a several months ago. The weight savings was about 2.5 lbs and it is considerably smaller, giving better access to the lower back side of the engine. They apear to be well made and are put together with orings instead of gaskets. The rear plate and arm will swivel 360 degrees by loosing the rear screws a couple of turns. The customer service was top notch when I called them even though they knew I purchased it used. After answering my questions they asked for my name and address so they could transfer the remaining warrenty to me.

http://mooneyspace.com/topic/14066-fs-pcu5000-ath-1/#entry186811

[tony]

I have the PCU 5000 installed as well and I would recommend it. 

[Cwalsh7997]

I'm having a problem in mine where my rpm during takeoff will go to almost 2900rpm????

[carusoam]

There are some important things to avoid regarding overspeeding the engine. How much for how long are the key measurements.

Talk to your mechanic before things get expensive.

Look up Lycoming guidance on the same subject to get educated before talking to your mechanic.

Or, is it a bad RPM gauge?

Best regards,

-a-

[Marauder]

I'm having a problem in mine where my rpm during takeoff will go to almost 2900rpm????

As Anthony pointed out, you want to make sure it is not an indication problem over a governor issue. You should never see 2,900 on a plane with a 2,700 redline.

On page 7 of the document below there are details on what to do with a prop over speed situation: http://flighttraining.aopa.org/students/presolo/topics/SA06_Propeller_Safety.pdf

Sent from my iPad using Tapatalk

[Lood]

Hi gents,

Sorry for my absence, been away for a sporting event with my kids and didn't have access.

 

To answer the tach question, I'm sure it is not a failing tacho. My reason for being quite sure is that I have the digital readout on the JPI EDM900 and I have the OEM cable driven one. Both correspond rather closely and after the EDM900 installation, I was actually quite amazed at how accurate my old, stock gauge was.

Both these can't lie equally at the same time and like I said, the lack of power during take off and initial climb out on those reduced power days, is very very noticeable.

In fact, when my AME came to fetch my Mooney, his partner, also a qualified AME, remarked that he could actually hear that the engine was not getting full rpm when it ran past as during take off.

 

Please enlighten me: can I fit a McCauley on my engine, to drive the Hartzell prop? I got quotes on both the PCU5000 and Hartzell and it's probably not a big deal if you live in the US, but in our money, landed here it is going to set me back just shy of R30k!!!!! Then it still has to be installed...

[Tommy]

I'm having a problem in mine where my rpm during takeoff will go to almost 2900rpm????

 

You are awfully close to the 110% over speed! Lycoming stipulated that if you have an 110% overspeed - even just for briefest moment - you will need a prop inspection and a possible engine tear down inspection too!

 

Use an optical tach to confirm that you are not in 2900rpm. If you are and you had it in 2900rpm the whole take off and you did it few times....

[Cody Stallings]

Yes you can. The McCauley Gov bolts right up!