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Prop governor or something else

dreed

Well Known Member
Need some input from the Vans brain trust. Was going to fly the plane for the first time yesterday and the prop would not cycle. I had to get a customer lenth prop cable and with trying to limit the ground run time till yesterday had not run the engine since I got the cable installed.

Anyway, we had several really smart people around with lots of RV time. After getting it warmed up and still not cycling we pulled the prop to make sure there was no crank plug (IO-390)- and there was not.

Setup (all new)
IO-390
Hartzell Composite CS Prop
Hartzell prop governor (from Vans)

Steps we took:

Verified the stops were both being hit

Removed prop looked for crank plug- no plug, but we did not get very much oil that drained out either.

Warmed up again, took to 2200-2300 RPM, would not pull down other than one very small pull once but would never do it again- had Mike Seager sitting next to me running the controls so no user error :D)

Pulled the governor to make sure the prop circuit was not being blocked by a gasket, etc. - all good

Re-clocked the gov to the RV-14 instructions. I think this is more mounting/angle but we tried.

Reinstalled and tried cycling again and nothing



Thoughts? or ideas? Anyone ever see a bad governor out of the box? Hoping not an internal engine issue. Sticky prop?

I found this article and seperate Lycoming SB that I'll attempt. May need to make a block off plate for the lyc DB.

Seem like the avweb one is easy and should be where we start.

https://www.avweb.com/ownership/propeller-governor-diagnostics/


https://www.lycoming.com/sites/default/files/Propeller%20Oil%20Control%20Leak%20Test%20Procedure.pdf


Thanks in advance!
dan
 
Had a buddy with a newly purchased RV-8 and Whirlwind have this happen on his way home after purchase... I told him to do an aborted takeoff to see if the prop goes into range on the roll (RPM sag at 20 knots). Worked fine. Some props won't cycle on the ground at first. My Rocket does it sometimes.
 
Governor

I have a different setup, IO540, Hartzell Governor, and an MT prop.

My experience was that it took quite a few tries to get the prop to cycle the first time. One thing to note is that the Hartzell Governor doesn’t cycle below 2000 rpm. Once it completed that first cycle, no other issues were noted...and that Governor is ROCK solid; it never hunts once it is set...
 
Thanks Guys-

I am headed down to the shop. May try the simple air trick in the prop circuit and then put it back together and give an aborted TO a go. We've 5200 feet of runway to work with.

dan
 
When you pulled the prop off did you see evidence that oil was flowing to the prop.

I agree with others that it can take a decent amount of effort to get all the air out of a new hub for the first flight and generally the S series governor won't start increasing pitch until 1800-2000 RPM.

Larry
 
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I'm not saying this is your problem...but;

A friend of mine building a -14A recently installed his IO-390 and propellor governor and he asked me to look at it.

I noticed that he inadvertently left the pad cover seal in place when he removed the cover and "doubled up" when he installed the prop. governor.

Part #25 in the attached picture
 

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"Removed prop looked for crank plug- no plug, but we did not get very much oil that drained out either."

There should not be a plug in the front end of the crank but there SHOULD be a plug about 8 inches back....just behind the hole that brings the oil in.
 
I never cycled my prop until the second flight. I didn't want to potentially starve brand new bearings of oil by exercising the prop. I also wanted to keep ground running, especially at power, at a minimum. I ran it for a total of about 20 minutes before the first flight during three runs at progressively higher RPMs. On the last run before first flight I very briefly went to as high RPM as I dared (taildragger). When I opened the throttle for takeoff and saw 2700, I knew for sure the governor was working and I didn't need to abort the takeoff. My choice was to not mess with it on the first flight. Left everything wide open and worked on break-in for about an hour. Temps under control - happy pilot. I reduced RPM using the prop control during the second flight, but not as a runup item, more as a break-in procedure. I wanted to vary the RPM at high manifold pressure to help seat the rings.

As far as exercising the prop before every flight goes, I usually don't. It worked in the air. I have no reason to think it won't work this flight. I don't really need to spend a lot of time sucking up dirt and gravel at the runup area. If the weather were very cold, maybe it'd be good to change out the oil in the prop with warmed up oil. In SoCal, not much of an issue most of the time.

Ed Holyoke
 
I'm curious Dan, did you guys ever get this figured out this weekend?

Hey Jereme- I did not. I went down to airport to watch another planes maiden flight, but had some work and home stuff I had to get done yesterday.

I am going to make up a block off plate with a port so we can do the official Lycoming differential pressure check to make sure it's in the normal oil pressure range. Work got in the way so far today, but I am going to try and get that finished up tonight so we can test.

If that checks out- aborted TO time to see if it pulls down.
 
I never cycled my prop until the second flight. I didn't want to potentially starve brand new bearings of oil by exercising the prop. I also wanted to keep ground running, especially at power, at a minimum. I ran it for a total of about 20 minutes before the first flight during three runs at progressively higher RPMs. On the last run before first flight I very briefly went to as high RPM as I dared (taildragger). When I opened the throttle for takeoff and saw 2700, I knew for sure the governor was working and I didn't need to abort the takeoff. My choice was to not mess with it on the first flight. Left everything wide open and worked on break-in for about an hour. Temps under control - happy pilot. I reduced RPM using the prop control during the second flight, but not as a runup item, more as a break-in procedure. I wanted to vary the RPM at high manifold pressure to help seat the rings.
Ed Holyoke

For break in I plan on running WOT and 2500RPM so need the prop working.
 
....Some props won't cycle on the ground at first....

Is this due to air in the system?

If so, is there a procedure to purge the air that doesn't involve running the engine?

And is it a general behavior for new constant speed engine/props?

Thanks,
Dave
 
For break in I plan on running WOT and 2500RPM so need the prop working.

If you are in forward motion and the prop remains at 2700, it's still "working". The governor starts throwing oil at the prop within about 20 knots on TO roll and keeps throwing more pitch as the airspeed increases. The prop is not "fixed" with the blue knob all the way in - you've just set it to govern at the maximum speed.
 
Is this due to air in the system?

If so, is there a procedure to purge the air that doesn't involve running the engine?

And is it a general behavior for new constant speed engine/props?

Thanks,
Dave

Yes, air in the crankshaft cavity. The air has to pass through the front crank bearing to get out. There is not a lot of oil flow (long bearing) so it can take a few minutes. And it is pretty common.

Something seems odd about this one though. It only takes 20PSI of air pressure to achieve full coarse pitch if the prop does not have air loads. It begins to move at about 10psi. One could provide oil downstream of the governor, but it would be a pain to do and not really solve the basic problem. It could help in diagnostics.

If the air test is performed and fails, then the aft crank plug could be missing.
 
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Hey Folks- quick update. Air test moved the blades no problem. I reinstalled the governor last night and will do another attempt at cycling this morning, and likely an aborted takeoff if she won't cycle in the runup area.

If that doesn't do it, I am going to try another governor. Just wish Vans had the PCU5000 but this Hartzell one should still be under warranty

I guess it is all about the education afrerall :)
 
Update:- Welp, high speed taxi/aborted TO didn't do the trick either.

Talked to a governor service shop in Olympia, WA and may send it up there tomorrow for bench check. They did suggest to just pull the lever all the way out, let it warm up and then run it up to see if I get some oil flowing to the hub but sure seems like I should have plenty of oil out there by now.

I am also finishing up the test plate and will do the oil pressure at the governor inlet port test and the differential/leakdown test on the prop circuit.

More to come
 
Super bummed for you on this one Dan, was hoping it was an easy fix for you!

A local -6A driver told me once, "building a plane is like fighting a war, you just keep fighting until you have won"
 
Update:- Welp, high speed taxi/aborted TO didn't do the trick either.

Talked to a governor service shop in Olympia, WA and may send it up there tomorrow for bench check. They did suggest to just pull the lever all the way out, let it warm up and then run it up to see if I get some oil flowing to the hub but sure seems like I should have plenty of oil out there by now.

I am also finishing up the test plate and will do the oil pressure at the governor inlet port test and the differential/leakdown test on the prop circuit.

More to come

This is what I would do.

The engine did not know you were moving, oil pressure is regulated to the pump inlet. the outlet to the prop is regulated based on lever and RPM. 2000 rpm is plenty to have this function. If not something is wrong. Moving is not necessary and high speed taxi is less safe than tied down. And you MUST tie it down. A friend jumped the blocks on his 14 when the spinning interval of the engine and prop turned in to static thrust when the rpm dropped. He barely got it stopped as others ran from the moving plane.
 
Take a look at this thread, see if there might be something in there that can help.

https://vansairforce.net/community/showthread.php?t=167258

Thanks Mike! That was a new thread for me, but many of those items are part of my troubleshooting tree.

I'm doing the lycoming leak down today (we just did shop air on the prop circuit before without testing leakage).

I did look down the center bore of the crank previously when this first came up, but it was a cursory check, not a really investigative look. If the breakdown is out of spec at all the prop is coming off again.

I'd much rather be flying- but I see this as just part of the journey.
 
Super bummed for you on this one Dan, was hoping it was an easy fix for you!

A local -6A driver told me once, "building a plane is like fighting a war, you just keep fighting until you have won"

Thanks Jereme!

We'll figure it out! One thing I've gotten really good at is pulling the baffling and the governor :)

Unfortunately, the thing that funds the hobby (work) has slowed me a bit this week on the plane.
 
You’re doing all the right things, so this is puzzling - time for a WAY out of the box idea!

Are you sure that you have your EFIS set properly for your engine? If not, you might not be reading accurate RPM - as in, reading a third low. Many years ago, when I originally started my RV-8, everything seemed and sounded fine - until I went to full power for the first take-off, and only got 1800 RPM (indicated). turned out the EIS was set for a six cylinder. Not knowing what the airplane should sound/feel like, it wasn’t obvious.

Very unlikely this is your problem, but you never know....

Paul
 
You’re doing all the right things, so this is puzzling - time for a WAY out of the box idea!

Are you sure that you have your EFIS set properly for your engine? If not, you might not be reading accurate RPM - as in, reading a third low. Many years ago, when I originally started my RV-8, everything seemed and sounded fine - until I went to full power for the first take-off, and only got 1800 RPM (indicated). turned out the EIS was set for a six cylinder. Not knowing what the airplane should sound/feel like, it wasn’t obvious.

Very unlikely this is your problem, but you never know....

Paul

Thanks Paul!

Good thoughts and I will definitely verify. Rob at Advanced was kind enough to help with the setup on the EFIS and update to the latest and greatest software a couple weeks back.
Also, Mike Seager was the guy running the controls during a couple of the trials and I am pretty sure his ear is much better trained than mine.

But... you never know. :)
 
Kind of an update

For those following along-

The test plate mostly complete, I still need to add one more port for the governor inlet oil pressure connection and need a tap, or an adapter to run the same thread size/pitch in the plate. Have most of what I need so that should go pretty quickly

I did a cold differential/leak down test tonight, thinking if there were a massive leak internally I could skip the oil pressure check and start looking for other reasons. Fortunately no massive leak, in fact very little differential at all. The prop blades also moved nice and smoothly with the air pressure applied.

The lycoming SB calls for the engine to be in operating temp range and 40 PSI inlet and acceptable differential range of 5-35 PSI. Cold I had 40 PSI inlet and 39 PSI on the differential side. I am hoping that warmed up there is a bit more clearance and I get within range.

Pardon my plate- I couldn't find 1/2" alu locally and used some scrap, but had to use old nuts as spacers since the studs have an non-threaded area. Also, the pic makes it look like the leak-down tester is on the lower right stud- I can assure you it is not, but it is close enough that I'll need to shave a nut down to get it on the stud and still have clearance for the inlet port. That said, the other three were enough to get it tight enough not to leak.

More to come-

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Nice piece of tooling - that one needs to go in a special drawer for someone to borrow in the future!
 
Update-

Had to make a quick trip over to pickup an IFD540 from Advanced (my girlfriend too) so the plane got no love this weekend. I did complete the plate Friday before I left to test the oil pressure too.

This morning, grabbed a partner and got the plane warmed up and pressure at the governor pad was about 2-3psi below main oil pressure which was within spec of -5 from main oil pressure.

At oil temp of 154 degrees before shutdown, and checking leak down which took a about 15 min post shut down as I had a smallish leak at the pad with only three nuts due to clearance, so I had to make a smaller diameter spacer to get some torque on all 4 corners (did not have this leak when cold). Once this was done, the leak down of 20/40 so well within the specifications of 6-35lbs of on the differential pressure check.

Just for giggles, I checked the prop circuit and the prop started to move about 35lpsi on the prop circuit side. Granted not the same as a an engine running but all signs point to governor which is on it's way to be tested (was brand new from Vans).

more to come- but knocking off the lit of potential issues.

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Hmmmm, air will go through smaller holes than oil, so it makes one wonder why the leakage is so small. If the front plug it out of the crank and the rear plug is installed, the the only other possibility seems to be a mis aligned bearing shell. You are not there yet, but having tested my IO360 with the same leak test I don't remember it being 40-40 even cold. Now, it takes a bit of time to push out all the oil from the bearings to truly determine the leak rate of the air.

I am really looking forward to the final root cause.

BTW - nice adapter, I had to install a 1/8"X 3" nipple to clear that one nut.
 
Thanks Bill!

I sure hope that is not the case :) and the cold test was done without getting any of the oil from the bearing/hub. I had quite a bit of back flow spraying all over me when I Removed the hose that evening so I hope that viscosity of the oil was causing the high reading.

Today we followed the SB to the letter and both test appeared to be perfectly within spec. I found the test cell data from Aerosport and they reported 14/40 with a bit higher oil temp. I did end up using a different fitting that allowed me to get a nut on that bottom left stud and get a good tight seal all around today.

Will be interesting to see what the governor shop finds.

What do you find on yours?
 
Update

Welp... I can't recall being so happy to receive a call that an airplane part was FUBAR.

Governor shop called and after testing my brand new hartzell is no putting out any pressure/has no control.

I am going to Hartz first thing tomorrow to see what they'll do. After a little research the warranty is 1 year from in-service so I should be good. But honestly at this point, if I need to spring for a new one I am ready to.
 
Welp... I can't recall being so happy to receive a call that an airplane part was FUBAR.

Governor shop called and after testing my brand new hartzell is no putting out any pressure/has no control.

I am going to Hartz first thing tomorrow to see what they'll do. After a little research the warranty is 1 year from in-service so I should be good. But honestly at this point, if I need to spring for a new one I am ready to.

Glad you got an answer dude! Hopefully Hartzell will make it right but if all else fails just slap a PCU5000 in there!
 
Thanks Jereme! Hope to have one soon. I may end up with the PCU- we'll see

Thanks to you too Mike! All of those are smoking deals, but the time frame is a bit outside of what I need. Still may consider picking one up at those prices though
 
You might make a deal with someone who has a gov sitting around that will not need it for a few months. Get theirs, and when the new group buy comes around, you buy them a replacement??

Or, just contact the folks that are doing the group buy, and see if there is any chance of getting one early due to your immediate need?
 
Thanks Mike!

I spoke with the folks at Hartzell this AM. I think the are a bit perplexed too as all governors are tested before shipment. I am going to have the governor shop ship directly to them for investigation/warranty/repair. They said turn around should be a couple weeks. If I can borrow one locally I will, but 2 weeks is probably about as fast as I could get another one here. Also, since I've already spent the $1600ish on this one I'd sure like to see if work if at all possible.

Not sure what could be wrong if it worked when it went out the door but didn't work when we installed it. We took it right out of the box and installed it and it didn't work. We later re-clocked the top to get better geometry (found in the RV-14 manual) but it made no difference in operations. As much as I would rather be flying, I am very interested to see what is found when they test/inspect it.

The governor shop said the new style Hartzell's are rock solid and this was a first for him (DOA). He was also a fan of the PCU's but said this unit should absolutely work well with my setup and said these are great at holding speed and no RPM hunting even with rapid changes.

On a funny note- the gentlemen at Hartzell asked if I was Dan Reed, apparently his colleague is either and RV guy, or was on the boards and had seen all of my posts on this issue. :D As I told him- at least they can see I've been doing everything I can to isolate the issue between engine, prop or governor and didn't send the governor off until I was pretty darn sure it was the potential failure point.
 
The PCU5000 guys are also on here listening in :) Hopefully things work out!

We are running a group buy for the VAF Members right now. Unfortunately it doesn't end until Aug 1st. I'm sure you want to be back up in the air by then.
 
Same issue > more info

Yesterday I did an initial engine run on my YIO-390-EXP with Hartzell blended and Hartzell governor S-1-79 (Vans' standard for the 390).

Following two days of getting my facts together and a few contacts each to both Hartzell and Lycoming tech support getting some directions, then talking things over with Stirling at Van's. Sorting out little bit of conflicting info and advice that got resolved in the end.

Long story, short > Ends up that I do have the correct governor for the engine and prop, a little mis-information eventually corrected - about maybe not having the correct governor, the S-1-79 is the correct governor, 0.895:1 (gov:engn) gear ratio.

The prop not cycling during first run-up may be that the procedure is to get the engine oil temp up to at least 90 F and the rpm to around 2100 and then pull the prop control to coarse and leave it there until the engine/governor/prop purges the air in the system, reportedly typically takes about 1 minute but can be as long as 2-3 minutes.

Seems that cycling to coarse for the typical few seconds as you do during a pre-takeoff run up doesn't purge the air from the system. This procedure is not published anywhere - Stirling suggested it to me today. Makes sense to me, I hope it does the trick to get the juices flowing.

I'm going to try this procedure tomorrow morning when it's cool.

I'll report the results afterwards.

>> Did another run-up this morning; rpm to 2000, pulled control to coarse pitch, took about 15 seconds, prop cycled. Cycled a few more times and then shut down. Happy.
 
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Jeff, both of our props failed to cycle initially when we attempted at the then-recommended 1800 rpm. Multiple contacts with Hartzell, Lycoming, and Vic Syracuse, including returning both governors to Hartzell for testing, concluded we needed to cycle at 2100 rpm. Problem solved. It did take a few cycle attempts the first time. I predict you will be fine. ;)
 
Was there any resolution with the Hartzell governor? Did it ultimately perform/behave the way that it should?
 
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