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philipguziec(at)yahoo.com
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 Posted: Mon Aug 02, 2010 3:47 pm Post subject: IO 720 Governor/Oil Pressure Issue |
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I've got an issue with my prop governor and oil pressure on my right engine, LYC
IO 720. The oil pressure was at the low end of the range in cruise, and there
was no more adjustment available, so a new spring was fitted, which brought
cruise oil pressure up to match the left engine in mid-range but idle is still
at the bottom of the range. The prop also won't come off the stops, staying at
high RPM. The only change during annual was that the unfeathering accumulator
was rebuilt.
The governor is going out for a test and potential overhaul, but the oil
pressure has me concerned. The plane is new to me, so I don't have any trend
data on the oil pressure. The governor problem, however, is new.
Anyone familiar with common Lyc failure modes? I have some thoughts and
concerns, but thought I'd get a fresh set of eyes on the problem. I know a few
commanders are fitted with IO 720s.
Thanks
Phil
'60 Twin Bonanza Excalibur
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blorber(at)southwestcirru
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| Posted: Mon Aug 02, 2010 4:33 pm Post subject: IO 720 Governor/Oil Pressure Issue |
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Completely off-topic, but why does a T-Bone need an accumulator?
Maybe a question for the older heads? Were they used for training at
some point?
Brock
Philip Guziec wrote:
| Quote: |
I've got an issue with my prop governor and oil pressure on my right engine, LYC
IO 720. The oil pressure was at the low end of the range in cruise, and there
was no more adjustment available, so a new spring was fitted, which brought
cruise oil pressure up to match the left engine in mid-range but idle is still
at the bottom of the range. The prop also won't come off the stops, staying at
high RPM. The only change during annual was that the unfeathering accumulator
was rebuilt.
The governor is going out for a test and potential overhaul, but the oil
pressure has me concerned. The plane is new to me, so I don't have any trend
data on the oil pressure. The governor problem, however, is new.
Anyone familiar with common Lyc failure modes? I have some thoughts and
concerns, but thought I'd get a fresh set of eyes on the problem. I know a few
commanders are fitted with IO 720s.
Thanks
Phil
'60 Twin Bonanza Excalibur
|
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moe-rosspistons(at)hotmai
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| Posted: Mon Aug 02, 2010 5:21 pm Post subject: IO 720 Governor/Oil Pressure Issue |
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Brock,
Before you panic check the seat and plunger behind the oil relief spring.
Some time ago I had the same problem with one of my IGS540B1C engines. This
can be a real problem when the oil pressure goes below 35 PSI at hot idle,
as the injector goes full rich. After removing the oil pressure adjusting
nut, spring and piston there was a small piece which was preventing the oil
relief piston from seating. When the engine was at above about 2,800 RPM
the oil supply was great enough to overcome this "leak hole" and everything
was ok, however at low RPM when the pump volume was low too much of the oil
was bypassing and the pump was not pumping enough hot thin oil to overcome
the leak and consiquently the oil pressure was low. Fortunately, I had
suffered the same problem back in the '80s with my Chrysler powered dragster
and I just happened to remember it. Hopefully this is the problem because
it only takes about 15 minutes to fix and at no cost.
Regards,
Moe Mills
N680RR
680Fp
--------------------------------------------------
From: "Brock Lorber" <blorber(at)southwestcirrus.com>
Sent: Monday, August 02, 2010 5:27 PM
To: <commander-list(at)matronics.com>
Subject: Re: IO 720 Governor/Oil Pressure Issue
| Quote: |
<blorber(at)southwestcirrus.com>
Completely off-topic, but why does a T-Bone need an accumulator?
Maybe a question for the older heads? Were they used for training at
some point?
Brock
Philip Guziec wrote:
>
> <philipguziec(at)yahoo.com>
>
> I've got an issue with my prop governor and oil pressure on my right
> engine, LYC
> IO 720. The oil pressure was at the low end of the range in cruise, and
> there
> was no more adjustment available, so a new spring was fitted, which
> brought
> cruise oil pressure up to match the left engine in mid-range but idle is
> still
> at the bottom of the range. The prop also won't come off the stops,
> staying at
> high RPM. The only change during annual was that the unfeathering
> accumulator
> was rebuilt.
>
> The governor is going out for a test and potential overhaul, but the oil
> pressure has me concerned. The plane is new to me, so I don't have any
> trend
> data on the oil pressure. The governor problem, however, is new.
>
> Anyone familiar with common Lyc failure modes? I have some thoughts and
> concerns, but thought I'd get a fresh set of eyes on the problem. I know
> a few
> commanders are fitted with IO 720s.
>
> Thanks
> Phil
> '60 Twin Bonanza Excalibur
>
|
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blorber(at)southwestcirru
Guest
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| Posted: Mon Aug 02, 2010 6:39 pm Post subject: IO 720 Governor/Oil Pressure Issue |
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Phil:
What Moe said.
Moe:
At this point in my life, the only panic I have about a commander is
that a client may underestimate the cost of TLC. 
Brock
Jack B. Mills wrote:
| Quote: |
<moe-rosspistons(at)hotmail.com>
Brock,
Before you panic check the seat and plunger behind the oil relief
spring. Some time ago I had the same problem with one of my IGS540B1C
engines. This can be a real problem when the oil pressure goes below 35
PSI at hot idle, as the injector goes full rich. After removing the oil
pressure adjusting nut, spring and piston there was a small piece which
was preventing the oil relief piston from seating. When the engine was
at above about 2,800 RPM the oil supply was great enough to overcome
this "leak hole" and everything was ok, however at low RPM when the pump
volume was low too much of the oil was bypassing and the pump was not
pumping enough hot thin oil to overcome the leak and consiquently the
oil pressure was low. Fortunately, I had suffered the same problem back
in the '80s with my Chrysler powered dragster and I just happened to
remember it. Hopefully this is the problem because it only takes about
15 minutes to fix and at no cost.
Regards,
Moe Mills
N680RR
680Fp
--------------------------------------------------
From: "Brock Lorber" <blorber(at)southwestcirrus.com>
Sent: Monday, August 02, 2010 5:27 PM
To: <commander-list(at)matronics.com>
Subject: Re: IO 720 Governor/Oil Pressure Issue
>
> <blorber(at)southwestcirrus.com>
>
> Completely off-topic, but why does a T-Bone need an accumulator?
>
> Maybe a question for the older heads? Were they used for training at
> some point?
>
> Brock
>
> Philip Guziec wrote:
>>
>> <philipguziec(at)yahoo.com>
>>
>> I've got an issue with my prop governor and oil pressure on my right
>> engine, LYC
>> IO 720. The oil pressure was at the low end of the range in cruise,
>> and there
>> was no more adjustment available, so a new spring was fitted, which
>> brought
>> cruise oil pressure up to match the left engine in mid-range but idle
>> is still
>> at the bottom of the range. The prop also won't come off the stops,
>> staying at
>> high RPM. The only change during annual was that the unfeathering
>> accumulator
>> was rebuilt.
>>
>> The governor is going out for a test and potential overhaul, but the oil
>> pressure has me concerned. The plane is new to me, so I don't have
>> any trend
>> data on the oil pressure. The governor problem, however, is new.
>>
>> Anyone familiar with common Lyc failure modes? I have some thoughts and
>> concerns, but thought I'd get a fresh set of eyes on the problem. I
>> know a few
>> commanders are fitted with IO 720s.
>>
>> Thanks
>> Phil
>> '60 Twin Bonanza Excalibur
>>
>>
>>
>>
>>
|
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moe-rosspistons(at)hotmai
Guest
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| Posted: Mon Aug 02, 2010 7:02 pm Post subject: IO 720 Governor/Oil Pressure Issue |
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|
Brock,
Wait until you get old and are not IFR current, and talk to your insurance
company about an older pressurized Commander. Panic will set in.
Moe
--------------------------------------------------
From: "Brock Lorber" <blorber(at)southwestcirrus.com>
Sent: Monday, August 02, 2010 7:39 PM
To: <commander-list(at)matronics.com>
Subject: Re: IO 720 Governor/Oil Pressure Issue
| Quote: |
<blorber(at)southwestcirrus.com>
Phil:
What Moe said.
Moe:
At this point in my life, the only panic I have about a commander is
that a client may underestimate the cost of TLC.
Brock
Jack B. Mills wrote:
>
> <moe-rosspistons(at)hotmail.com>
>
> Brock,
>
> Before you panic check the seat and plunger behind the oil relief
> spring. Some time ago I had the same problem with one of my IGS540B1C
> engines. This can be a real problem when the oil pressure goes below 35
> PSI at hot idle, as the injector goes full rich. After removing the oil
> pressure adjusting nut, spring and piston there was a small piece which
> was preventing the oil relief piston from seating. When the engine was
> at above about 2,800 RPM the oil supply was great enough to overcome
> this "leak hole" and everything was ok, however at low RPM when the pump
> volume was low too much of the oil was bypassing and the pump was not
> pumping enough hot thin oil to overcome the leak and consiquently the
> oil pressure was low. Fortunately, I had suffered the same problem back
> in the '80s with my Chrysler powered dragster and I just happened to
> remember it. Hopefully this is the problem because it only takes about
> 15 minutes to fix and at no cost.
>
> Regards,
> Moe Mills
> N680RR
> 680Fp
>
> --------------------------------------------------
> From: "Brock Lorber" <blorber(at)southwestcirrus.com>
> Sent: Monday, August 02, 2010 5:27 PM
> To: <commander-list(at)matronics.com>
> Subject: Re: IO 720 Governor/Oil Pressure Issue
>
>>
>> <blorber(at)southwestcirrus.com>
>>
>> Completely off-topic, but why does a T-Bone need an accumulator?
>>
>> Maybe a question for the older heads? Were they used for training at
>> some point?
>>
>> Brock
>>
>> Philip Guziec wrote:
>>>
>>> <philipguziec(at)yahoo.com>
>>>
>>> I've got an issue with my prop governor and oil pressure on my right
>>> engine, LYC
>>> IO 720. The oil pressure was at the low end of the range in cruise,
>>> and there
>>> was no more adjustment available, so a new spring was fitted, which
>>> brought
>>> cruise oil pressure up to match the left engine in mid-range but idle
>>> is still
>>> at the bottom of the range. The prop also won't come off the stops,
>>> staying at
>>> high RPM. The only change during annual was that the unfeathering
>>> accumulator
>>> was rebuilt.
>>>
>>> The governor is going out for a test and potential overhaul, but the
>>> oil
>>> pressure has me concerned. The plane is new to me, so I don't have
>>> any trend
>>> data on the oil pressure. The governor problem, however, is new.
>>>
>>> Anyone familiar with common Lyc failure modes? I have some thoughts
>>> and
>>> concerns, but thought I'd get a fresh set of eyes on the problem. I
>>> know a few
>>> commanders are fitted with IO 720s.
>>>
>>> Thanks
>>> Phil
>>> '60 Twin Bonanza Excalibur
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>
|
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cloudcraft(at)aol.com
Guest
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| Posted: Mon Aug 02, 2010 8:41 pm Post subject: IO 720 Governor/Oil Pressure Issue |
|
|
| Quote: | | Quote: | Completely off-topic, but why does a T-Bone need an accumulator?
Maybe a question for the older heads? Were they used for training at
some point?
Brock
|
|
Brock,
While not quite comfortable with being called one of the older heads, I guess I am because I've flown AC680-F series that had accumulators. They weren't very effective but they were there to help with restarting the IGSO-540s.
By the way, I had about a 50/50 success rate with restarting those beasts after a shut-down. The IGSO-540s were certainly not engines recommended for multi-engine flight training. I think the accumulators provided a false sense of security -- or -- they worked really well 40 years ago and not since.
Moe, that was some great information on the oil pressure setting for the IO-720 our T-Bone brother was asking about. Thanks for posting that.
The 680F series Commanders and the Beech Twin Bonanzas were direct competitors at the time. Both had similar power plants (Lyc. xGSO-540 and Simmonds fuel injectors) and interestingly, both went through an engine / airframe upgrade program: The Mr. RPM for the Commanders and the Excalibur for the T-Bones. There's lots of cross-over for these types when it comes to owning and operating them now.
Keith S. Gordon
Wing Commander Gordon
Life is not simple anywhere. Probably less so elsewhere.
--
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