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John Car

PMF 3200 Engine?

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I think as long as you can get valve springs they’re still airworthy. 

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57 minutes ago, jetdriven said:

I think as long as you can get valve springs they’re still airworthy. 

I thought about this in the past.  Porsche destroyed all the spare parts including valve springs.

So if I owned one, I would check into who makes valve springs for Porsche Race engines.  Then have them supply what I need, for "owner manufactured" parts.

However, another situation may, or may not surface.  Can an A&P repair an engine, or replace valve springs, that they have never received training for?

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On 3/12/2019 at 2:18 PM, Bob said:

I thought about this in the past.  Porsche destroyed all the spare parts including valve springs.

So if I owned one, I would check into who makes valve springs for Porsche Race engines.  Then have them supply what I need, for "owner manufactured" parts.

However, another situation may, or may not surface.  Can an A&P repair an engine, or replace valve springs, that they have never received training for?

I am betting an adequate valve spring replacement is available from the Porsche auto engine inventory. I would think the gearbox to be most problematic.

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1 hour ago, Shadrach said:

I am betting an adequate valve spring replacement is available from the Porsche auto engine inventory. I would think the gearbox to be most problematic.

Wouldn't using the auto version be replacing the valve springs with a wrong part in the FAA's eyes?

Porsche offered a engine swap to current PFM owners at the time.  This was done to allow Porsche to get out and remove their liability. It was split 70K to Porsche and 30K to the owner and the owners basically ended up with an Ovation with a lower maximum gross weigh.  When hurricane Charlie hit and destroyed all but 9 US and 2 Australian unconverted PFM's, Porsche destroyed all the spares to remove the rest of their liability.

As far as using springs from Porsche for a 3.2 or 3.3 Turbo engine......I personally would pass and go to a aftermarket company.  Porsche may sell you comparable springs, however I would bet that they would not assist you in owner manufactured springs.  Additionally I would not be interested in replacing the springs with the exact same spring, with a different part number, only to have the same weak link in the engine that caused the 500 replacement mandate to begin with.  

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I’m not sure how you can substitute the valve springs. The original part is no longer available. They were also called out in an AD. You could substitute others form race cars etc but how do you prove they are the same or better?

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3 minutes ago, jetdriven said:

I’m not sure how you can substitute the valve springs. The original part is no longer available. They were also called out in an AD. You could substitute others form race cars etc but how do you prove they are the same or better?

I was speaking to functionality, not legality.   It's a 3.2L, aircooled, Mezger designed, flat six that produces max power at a paltry 5300rpm.   I am betting that of the there are off the shelf  Porsche units that would work.  However, for legal purposes, why couldn't one have a company like Peterson Spring analyze and fabricate a set to the proper specifications as an owner produced part?

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2 hours ago, Bob said:

Wouldn't using the auto version be replacing the valve springs with a wrong part in the FAA's eyes?

Porsche offered a engine swap to current PFM owners at the time.  This was done to allow Porsche to get out and remove their liability. It was split 70K to Porsche and 30K to the owner and the owners basically ended up with an Ovation with a lower maximum gross weigh.  When hurricane Charlie hit and destroyed all but 9 US and 2 Australian unconverted PFM's, Porsche destroyed all the spares to remove the rest of their liability.

As far as using springs from Porsche for a 3.2 or 3.3 Turbo engine......I personally would pass and go to a aftermarket company.  Porsche may sell you comparable springs, however I would bet that they would not assist you in owner manufactured springs.  Additionally I would not be interested in replacing the springs with the exact same spring, with a different part number, only to have the same weak link in the engine that caused the 500 replacement mandate to begin with.  

was an updated spring ever made? Custom made springs are available. 

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12 minutes ago, Shadrach said:

I was speaking to functionality, not legality.   It's a 3.2L, aircooled, Mezger designed, flat six that produces max power at a paltry 5300rpm.   I am betting that of the there are off the shelf  Porsche units that would work.  However, for legal purposes, why couldn't one have a company like Peterson Spring analyze and fabricate a set to the proper specifications as an owner produced part?

Isn't there some kind of rule that allows for suitable replacements for orphaned airplanes?  I don't know the rule exactly but I read something about that somewhere at some point I think.

Seems crazy to ground an airplane permanently for a little spring.

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12 minutes ago, aviatoreb said:

Isn't there some kind of rule that allows for suitable replacements for orphaned airplanes?  I don't know the rule exactly but I read something about that somewhere at some point I think.

Seems crazy to ground an airplane permanently for a little spring.

Yes...owner produced parts.  According to Mike Busch's interpretation of the most recent FAA  memorandum (1993)

The owner may contract with a mechanic, a repair station, or even a non-certificated individual or firm (e.g., a machine shop) to manufacture the part for him, provided that the owner “participated in controlling the design, manufacture or quality of the part.”   

The FAA deems the part to be owner-produced if the owner does any of the following things:

• Provides the manufacturer with design or performance data from which to manufacture the part—this test would be met if the owner provides the manufacturer with the old part and asks that it be duplicated; or

• Provides materials to make the part; or

• Provides fabrication processes or assembly methods to be used in making the part; or

• Provides quality control procedures to be used in making the part; or

• Supervises the manufacture of the part.

In short, a part whose manufacture is contracted by the aircraft owner will qualify as “owner-produced” if the owner participates in the production of the part in any meaningful way at all.

There are a number of firms in the states that will custom spec valve springs.  Maintaining the reduction drive seems like the bigger challenge. 

Edited by Shadrach

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So many of the PFM engines got removed from service... and one particular hurricane in Florida...

There is at least one or two MSers with the PFM engine still...

There are many more with IO550s and IO540s in them...

The PFM was the first LB, just prior to the TLS...

The Bravo came along with a bunch of improvements for the airframe and the engine... more HP, oil cooled heads, and stronger legs...

PP thoughts only, not a historian...

Best regards,

-a-

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