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-   -   MT P860-3 Prop Gov fail. (https://vansairforce.net/community/showthread.php?t=140879)

GaryK 08-23-2016 06:26 PM

Vic,
Here are a few pics of the "form factor" I was asking about. For some reason the second pic is upside down (looking in the cowl inlet)

Thanks
Gary

[IMG][/IMG]


Kellym 08-24-2016 08:30 AM

Quote:

Originally Posted by woxofswa (Post 1105924)
This gets more confusinger by the day. I dug deep into my documents and there is a card (mostly in German), that says that the 860-3 is specified for 360
Series engines and 2500 RPM.

I've had supposed experts say that the ratio difference of WD and ND is a big huge ticking bomb deal and others say that it is very minor that all it does is slightly vary the speed of the pump and slightly change the distance throw of the arm to make a given change. .

It is clear that the P-860-3 will work on both the wide and narrow deck engines. It is also clear that it has the gear ratio specified for the narrow deck. The rpm specified is for the governor, not engine rpm, so 2700 times the gear ratio give. s you the governor rpm.
What is not clear is why Vans chose this version, when they have always sold wide deck engines, and the P-860-5 has the correct gear ratio for that engine. Also, MT's application document recommends a P-860-19 for the RV-10 with an MT 12B prop. Don't know anything about that version of the governor.
My P-860-5 is going back to MT today to have the SB31 done on it.

vic syracuse 08-24-2016 08:49 AM

I confirmed this week that the P-860-3 is the correct governor.

Vic

Weasel 08-24-2016 09:12 AM

Quote:

Originally Posted by Kellym (Post 1106092)
My P-860-5 is going back to MT today to have the SB31 done on it.

Without the SB31 being published how do you know it needs to be done? Are you aware that maintenance induced failures are a reality?

Bavafa 08-24-2016 09:41 AM

Does any one know the difference between a P860-4 and P860-3. I just looked up my paperwork and it indicates I have a P860-4

civengpe 08-24-2016 10:30 AM

Juergen from MT USA told me today that all P-860 are the exact same except for the clocking. He said he doesn't understand why MT does it that way, because it is very confusing.

This came up, because I asked him why the MT applicability chart shows the P-860-19 as the appropriate PG for the IO-540-D4A5, but MT sold me the -3.

Also, the SB has now been pushed back to Monday next week.

Please don't shoot the messenger here. I am only parroting what I was told an hour ago by MT. I am not a PG expert and barely have an idea of how the dang things work.

woxofswa 08-24-2016 10:47 AM

Quote:

Originally Posted by vic syracuse (Post 1106104)
I confirmed this week that the P-860-3 is the correct governor.

Vic

Can I ask who confirmed that and for what application? I'm at the point where three experts have four opinions on the matter. Not literally, but I'm definitely stuck right on top of the VOR if you catch my azimuth.

scsmith 08-24-2016 03:44 PM

Service interval?
 
I'm just discovering this thread, kinda late, but I think I read through all the details.

I checked my paperwork, and my MT P-860-4 governor was manufactured in 2008 (thankfully outside the affected time period), and has been in service since September 2009 -- so, 7 years. It has 400 hrs on it.

From this thread, I just learned that there is a 72-month service interval in addition to the 2000 hr service interval. That surprised me. Can someone speculate or explain why there would be a 6-year service limit on a prop governor? I would think that calendar age would have no bearing at all on the service life, except perhaps for age-hardening of elastomeric seals.

If this service interval should be respected, I am a year overdue, and from what I have learned in this thread, it costs $800. It would seem a sensible choice to consider just buying a PCU-5000X instead.
Another alternative would be to ignore the calendar-based service interval and just operating the MT P-860-4.

I would love to hear supporting arguments for why a 6-yr service interval should be respected on a prop governor.

Thanks

Bavafa 08-24-2016 04:00 PM

Quote:

Originally Posted by scsmith (Post 1106228)
I'm just discovering this thread, kinda late, but I think I read through all the details.

I checked my paperwork, and my MT P-860-4 governor was manufactured in 2008 (thankfully outside the affected time period), and has been in service since September 2009 -- so, 7 years. It has 400 hrs on it.

From this thread, I just learned that there is a 72-month service interval in addition to the 2000 hr service interval. That surprised me. Can someone speculate or explain why there would be a 6-year service limit on a prop governor? I would think that calendar age would have no bearing at all on the service life, except perhaps for age-hardening of elastomeric seals.

If this service interval should be respected, I am a year overdue, and from what I have learned in this thread, it costs $800. It would seem a sensible choice to consider just buying a PCU-5000X instead.
Another alternative would be to ignore the calendar-based service interval and just operating the MT P-860-4.

I would love to hear supporting arguments for why a 6-yr service interval should be respected on a prop governor.

Thanks

Steve,
I am in exact same boat as you are with the age/model of the governor and only slightly more hours, at 560 now. I have asked MT via e-mail this question and for a quote but if there is convincing evidence for this overhaul at 6 year interval, I will certainly go with Harzel governor which does not have this calendar base overhaul requirement. With only $400 or so more, I will put a brand new instead of an overhauled one.

GaryK 08-24-2016 04:26 PM

Based on some of the information posted by those who have spoken to MT directly there is a specific date range. Can we assume the new units being shipped by Vans today are OK.


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