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M20 Turbos Pressure relief valve


Vno

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During my annual the pressure relief valve for the turbo kit was found to be inop and damaged so bad that it probably can't be repaired. According to my shop, it is hard to find the exact replacement for this valve. Has anyone have a serviceable part they are willing to part with or have an idea of how to find one? I did see online there are two shops that say they have this part, but I tend to believe my A&P when he says they are not available. Or has anyone switched to a different part number and gotten field approval to replace it. The part number in question is 470930-9018.

Brian

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This is not a difficult problem.  Contact Aircraft Accessories in Oklahoma.   

https://aircraftaccessoriesofok.com/

They have the ability to take a pop-off valve of similar type, and change its crack pressure, and re-label it with the new part number due to the change.

Should not be difficult finding a valve that can be rebuilt, converted and re-tagged.

John Breda

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I had mine overhauled by Advanced Turbo Components.

When I called them they said they didn’t have authorization to overhaul it, but said to wait and they would call me back.

They called two hours later and said they had done all the paperwork and had authorization to overhaul it.

call them...

 

BTW.  It has more time on it sense overhaul then it had from new when it went bad.

Edited by N201MKTurbo
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Thanks. I wish I had seen this a couple days ago. I (my A&P) found a different shop to do the same. Unless the internal bellows are shot it should be repairable. I'm told the only difference in this part is the pressure setting for it to go off. 32.25". The next lower part number which is readily available goes off at 31.5". A difference the mechanic said is negligible and to the safer side. If only he could legally do it.

Brian

 

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On 10/15/2018 at 9:28 PM, M20F-1968 said:

I just tried to google search your part number, 470930-9018.  A number of sources come up.

John Breda

True and I tried them all. This part is unique to the STC and does not exist in any stock even though some websites say they have them. Nor does the manufacture plan to make anymore. Kinda blows.

Brian

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On 10/15/2018 at 9:25 PM, M20F-1968 said:

This is not a difficult problem.  Contact Aircraft Accessories in Oklahoma.   

https://aircraftaccessoriesofok.com/

They have the ability to take a pop-off valve of similar type, and change its crack pressure, and re-label it with the new part number due to the change.

Should not be difficult finding a valve that can be rebuilt, converted and re-tagged.

John Breda

This is true also and a path we looked at. The issue is they need the spec data for the part number to make it. That data is not available and we haven't been able to get it from the manufacturer. If anyone knows where it is or how to replicate it I would appreciate it.

Thanks John. All good advice.

Brian

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As an owner you have the authority to specify the manufacture or repair for parts of your airplane. You don't have to physically make the part yourself...you can ask a shop to make a valve that goes off at 32" or whatever is required for your installation. You just can't sell that part to someone else.

 

This reg was created for exactly your scenario when the OEM has disappeared and parts don't exist. Worse yet, the OEM data was lost before the business was closed. Even the FAA lost their copy of the original cert data, so it is REALLY gone.

 

 

 

Sent from my LG-US996 using Tapatalk

 

 

 

 

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  • 2 years later...

So, I'm working the same issue on an M20J with the M-20 Turbo installed. Valve has failed. Pops at 45".  470930-9018 was what was installed. having no luck at all sourcing a repair of replacement. Hartzell support stated they have drawings for it and the setting is 32.25" +- 0.25 but that is all they'd give me. Tried all the usual folks and still no luck.

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14 hours ago, DaveM said:

So, I'm working the same issue on an M20J with the M-20 Turbo installed. Valve has failed. Pops at 45".  470930-9018 was what was installed. having no luck at all sourcing a repair of replacement. Hartzell support stated they have drawings for it and the setting is 32.25" +- 0.25 but that is all they'd give me. Tried all the usual folks and still no luck.

Dave,

I had mine rebuilt by QAA with the proper settings. It works fine. I would start by trying to do that. The part number that is the problem is the 9018. You can find replacement valves and they are the identical valve (different part number) with different pressure settings. My tech found a common valve that would fit and the blow off setting was 31.5 inches. He liked that better but the STC doesn't allow any other part number. If your valve can't be rebuilt, then you will probably have to get an approval from the FAA to use a different part number (again same valve housing) with that lower setting.

Brian

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1 hour ago, Vno said:

Dave,

I had mine rebuilt by QAA with the proper settings. It works fine. I would start by trying to do that. The part number that is the problem is the 9018. You can find replacement valves and they are the identical valve (different part number) with different pressure settings. My tech found a common valve that would fit and the blow off setting was 31.5 inches. He liked that better but the STC doesn't allow any other part number. If your valve can't be rebuilt, then you will probably have to get an approval from the FAA to use a different part number (again same valve housing) with that lower setting.

Brian

Tried them and hit a brick wall. They sent me to Aerorecip. Called Hartzell. support there had the drawing and the setting info but could not help after that. Stated it was proprietary and not PMA'd.

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44 minutes ago, DaveM said:

Anyone know what happened to M-20 Turbos, Bill Sandman? I doubt he made parts for this system. Must be someone out there somewhere that knows something. May be looking for a wastegate for this system.

I talked to Bill Sandman quite a few times. The short version is He died and so did the company. 

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...and then his wife attempted to run it for a while with the help of a mechanic who ended up buying the STC. He then failed to complete the entire purchase and ended up in prison on unrelated but aviation related crimes. This person, from what I understand has been released from prison and still claims ownership somehow. Surviving family of Bill Sandman want nothing to do with it...this is my understanding.

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On 9/3/2021 at 9:55 PM, N201MKTurbo said:

 

I talked to Bill Sandman quite a few times. The short version is He died and so did the company. 

I believe the wastegate is the same as Mooney used in the fixed wastegate equipped 231.  The prints are the same parts that were designed by Rocket Engineering and used in the Turbo Bullet.  I understand Bill Sandman obtained the prints and started producing the same turbo system except installed it as a turbo normalized system without any modification of pistons on the IO-360.

John Breda 

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On 10/18/2018 at 12:20 PM, Vno said:

Thanks. I wish I had seen this a couple days ago. I (my A&P) found a different shop to do the same. Unless the internal bellows are shot it should be repairable. I'm told the only difference in this part is the pressure setting for it to go off. 32.25". The next lower part number which is readily available goes off at 31.5". A difference the mechanic said is negligible and to the safer side. If only he could legally do it.

Brian

 

There is no reason to quibble on a valve that pops off at 32.25" v. 31.5".  The 31.5" is actually preferable.  The intent on this valve is to save the engine should manifold pressure go above 30"  The Operation manual does not advise any operations above 30" (if it even allows that).   Replacing the Valve with one that pops off at 31.5" is well within the operating specifications of the system, and likely within the working tolerance of the valve.  This kind of problem can be solved with a propulsion DER if needed.

John Breda

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1 hour ago, M20F-1968 said:

I believe the wastegate is the same as Mooney used in the fixed wastegate equipped 231.  The prints are the same parts that were designed by Rocket Engineering and used in the Turbo Bullet.  I understand Bill Sandman obtained the prints and started producing the same turbo system except installed it as a turbo normalized system without any modification of pistons on the IO-360.

John Breda 

The fixed wastgate is the same as a 231. I doubt it will ever fail.

The turbo, scavenger pump and check valves are 231 parts too.

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1 hour ago, M20F-1968 said:

There is no reason to quibble on a valve that pops off at 32.25" v. 31.5".  The 31.5" is actually preferable.  The intent on this valve is to save the engine should manifold pressure go above 30"  The Operation manual does not advise any operations above 30" (if it even allows that).   Replacing the Valve with one that pops off at 31.5" is well within the operating specifications of the system, and likely within the working tolerance of the valve.  This kind of problem can be solved with a propulsion DER if needed.

John Breda

The function of this valve is different than a normal turbo system. It controls the upper deck pressure. It is what makes this system so stable.

It looks like a normal pop off valve, but it is actually an absolute pressure controller. It has an Android in it so it opens at an absolute pressure. A regular pop off valve opens at a gauge pressure.

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