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Viperdoc

Joined: 19 Apr 2014
Posts: 484
Location: 08A

Posted: Thu Apr 23, 2015 6:39 pm Post subject: Air Leak Advice

Sorry Mark, your answers did not show up on my email chain until now. Yes the gasket can be put on backwards but is pretty obvious if you fit the gasket to the base of the compressor first with Permatex 51813 anaerobic gasket maker. The alignment of the oil holes will be intuitive and the sealant does not for until it is heated.

Doc

Sent from my iPad

 	  Quote: 	
		   On Apr 23, 2015, at 9:22 PM, Roger Kemp <f16viperdoc(at)me.com> wrote:

 Gimp,

 Which gasket are you referring to? The aluminum crush washer on the check valve or the gasket on the accessory drive case. It is real tough to get the gasket forming the oil seal on base of the compressor as it mates to the accessory case wrong. I guess if you really worked hard at it one could though. 

 Doc

 Sent from my iPad

> On Apr 23, 2015, at 12:27 PM, AcroGimp <jlknolla(at)aol.com> wrote:

> 

> 

> 

> Checked the logs and compressor has 41 hrs of operation.

> 

> I have had a reverse rotation/dieseling event I think twice in about 15-16 flights, both times only a couple of blades but still it did happen.  Last occurrence was flight prior to flight where everything pumped up correctly, so 3 flights ago. 

> 

> When I overhauled the snot valve side check valve it was very dirty, the fill side was clean, so I am planning to overhaul PRV and snot valve during this down cycle, as well as putting a serious clean on the little piston valve in the coupler at the bottom of the compressor.

> 

> Until I remove the old compressor I won't know if it is a shear shaft issue or something else but I will absolutely check the compressor gasket for the oil passage.  Would you guys go back to the mech for compensation if the gasket was installed incorrectly (asking, first airplane and all)?

> 

> Thanks for the support and info...

> 

> 'Gimp

> 

> --------

> Owner/Pilot N6209F 1987 Yak-52

> COMM/ASEL/IFR/HP-Complex/TW

> 

> 

> 

> 

> Read this topic online here:

> 

> http://forums.matronics.com/viewtopic.php?p=441181#441181

> 

> 

> 

> 

> 

> 

> 

> 

> 

>

_________________
Viperdoc

Viperdoc

Joined: 19 Apr 2014
Posts: 484
Location: 08A

Posted: Thu Apr 23, 2015 6:59 pm Post subject: Air Leak Advice

Not sure what Apple auto correct was trying to say?? "The sealant does not activate until it is heated."

Doc



Sent from my iPad



 	  Quote: 	
		   On Apr 23, 2015, at 9:38 PM, Roger Kemp <f16viperdoc(at)me.com> wrote:

 

 

 

 Sorry Mark, your answers did not show up on my email chain until now. Yes the gasket can be put on backwards but is pretty obvious if you fit the gasket to the base of the compressor first with Permatex 51813 anaerobic gasket maker. The alignment of the oil holes will be intuitive and the sealant does not for until it is heated.

 Doc

 

 Sent from my iPad

 

> On Apr 23, 2015, at 9:22 PM, Roger Kemp <f16viperdoc(at)me.com> wrote:

> 

> 

> 

> Gimp,

> Which gasket are you referring to? The aluminum crush washer on the check valve or the gasket on the accessory drive case. It is real tough to get the gasket forming the oil seal on base of the compressor as it mates to the accessory case wrong. I guess if you really worked hard at it one could though. 

> Doc

> 

> Sent from my iPad

> 

>> On Apr 23, 2015, at 12:27 PM, AcroGimp <jlknolla(at)aol.com> wrote:

>> 

>> 

>> 

>> Checked the logs and compressor has 41 hrs of operation.

>> 

>> I have had a reverse rotation/dieseling event I think twice in about 15-16 flights, both times only a couple of blades but still it did happen.  Last occurrence was flight prior to flight where everything pumped up correctly, so 3 flights ago. 

>> 

>> When I overhauled the snot valve side check valve it was very dirty, the fill side was clean, so I am planning to overhaul PRV and snot valve during this down cycle, as well as putting a serious clean on the little piston valve in the coupler at the bottom of the compressor.

>> 

>> Until I remove the old compressor I won't know if it is a shear shaft issue or something else but I will absolutely check the compressor gasket for the oil passage.  Would you guys go back to the mech for compensation if the gasket was installed incorrectly (asking, first airplane and all)?

>> 

>> Thanks for the support and info...

>> 

>> 'Gimp

>> 

>> --------

>> Owner/Pilot N6209F 1987 Yak-52

>> COMM/ASEL/IFR/HP-Complex/TW

>> 

>> 

>> 

>> 

>> Read this topic online here:

>> 

>> http://forums.matronics.com/viewtopic.php?p=441181#441181

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

> 

> 

> 

> 

>

_________________
Viperdoc

dsavarese0812(at)bellsout
Guest

Posted: Fri Apr 24, 2015 4:21 am Post subject: Air Leak Advice

I'm not sure why anyone would use any type of "gasket maker" on the 

compressor to accessory case gasket because; 1- the studs the compressor 

mounts to are vertical and protrude from the accessory caseand I don't 

see how the gasket could slide off the studs when installing the 

compressor since it is place on the accessory case, not on the 

compressor.  2- If one truly needed to hold the gasket in place, then 

use fuel lube (also called Easy Turn) very sparingly.



http://www.aircraftspruce.com/catalog/cspages/ezturnlube.php?clickkey=9406



 	  Quote: 	
		   EZ Turn is a specialty lubricant/sealant used for fuel and oil line 

 valves & is resistant to high temps. Especially effective where high 

 octane fuels and aromatics are present. EZ Turn is also extremely 

 efficient as a gasket paste & anti- seize agent. EZ Turn will not gum, 

 crack or dry out. Each shipment is independently tested. Excellent for 

 tapered plug valves, aircraft engine manufacturing, and marine 

 applications. EZ Turn is the functional equivalent of fuel lube. 1 Lb. 

 can 


	




The problem I personally would have with any type of gasket maker, 

especially one that hardens, is if you ever have to remove the 

compressor in the future, removing the gasket compound from the 

accessory case surface could present a problem.



FWIW,

Dennis



A. Dennis Savarese

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1



On 4/23/2015 9:58 PM, Roger Kemp wrote:

 	  Quote: 	
		   



 Not sure what Apple auto correct was trying to say?? "The sealant does not activate until it is heated."

 Doc



 Sent from my iPad



> On Apr 23, 2015, at 9:38 PM, Roger Kemp <f16viperdoc(at)me.com> wrote:

>

> 

>

> Sorry Mark, your answers did not show up on my email chain until now. Yes the gasket can be put on backwards but is pretty obvious if you fit the gasket to the base of the compressor first with Permatex 51813 anaerobic gasket maker. The alignment of the oil holes will be intuitive and the sealant does not for until it is heated.

> Doc

>

> Sent from my iPad

>

>> On Apr 23, 2015, at 9:22 PM, Roger Kemp <f16viperdoc(at)me.com> wrote:

>>

>> 

>>

>> Gimp,

>> Which gasket are you referring to? The aluminum crush washer on the check valve or the gasket on the accessory drive case. It is real tough to get the gasket forming the oil seal on base of the compressor as it mates to the accessory case wrong. I guess if you really worked hard at it one could though.

>> Doc

>>

>> Sent from my iPad

>>

>>> On Apr 23, 2015, at 12:27 PM, AcroGimp <jlknolla(at)aol.com> wrote:

>>>

>>> 

>>>

>>> Checked the logs and compressor has 41 hrs of operation.

>>>

>>> I have had a reverse rotation/dieseling event I think twice in about 15-16 flights, both times only a couple of blades but still it did happen.  Last occurrence was flight prior to flight where everything pumped up correctly, so 3 flights ago.

>>>

>>> When I overhauled the snot valve side check valve it was very dirty, the fill side was clean, so I am planning to overhaul PRV and snot valve during this down cycle, as well as putting a serious clean on the little piston valve in the coupler at the bottom of the compressor.

>>>

>>> Until I remove the old compressor I won't know if it is a shear shaft issue or something else but I will absolutely check the compressor gasket for the oil passage.  Would you guys go back to the mech for compensation if the gasket was installed incorrectly (asking, first airplane and all)?

>>>

>>> Thanks for the support and info...

>>>

>>> 'Gimp

>>>

>>> --------

>>> Owner/Pilot N6209F 1987 Yak-52

>>> COMM/ASEL/IFR/HP-Complex/TW

>>>

>>>

>>>

>>>

>>> Read this topic online here:

>>>

>>> http://forums.matronics.com/viewtopic.php?p=441181#441181

>>>

>>>

>>>

>>>

>>>

>>>

>>>

>>>

>>>

>>>

>>

>>

>>

>>

>

>

mark.bitterlich(at)navy.m
Guest

Posted: Fri Apr 24, 2015 9:17 am Post subject: Air Leak Advice

Yes there one on the 50 Doc.  Maybe not on YOURS,  but on the three others I have had experience with ... yes.



Mark

--

mark.bitterlich(at)navy.m
Guest

Posted: Fri Apr 24, 2015 9:20 am Post subject: Air Leak Advice

When you pull the complete assembly apart in order to install a new compressor, there are two gaskets Doc.   They are not the same.



I do not use any form of gasket maker on these items.



Mark

--

mark.bitterlich(at)navy.m
Guest

Posted: Fri Apr 24, 2015 9:25 am Post subject: Air Leak Advice

Excuse the lack of grammar check.



Yes, there originally was one on the 50, and I own both a 74 and 84 model, both with cooling horns.  Also on the one I ferried out to Ramona some years back.   Pictures if you want.



Mark

--

mark.bitterlich(at)navy.m
Guest

Posted: Fri Apr 24, 2015 9:43 am Post subject: Air Leak Advice

To be specific, there is something called an ACCESSORY DRIVE.  It connects to the COMPRESSOR.   It also connects to the ENGINE.  There is a gasket in-between the engine and the accessory drive stage and then another gasket between the drive and the compressor itself.  When you order a new compressor, it does not come with an accessory drive piece attached.  



Thus two gaskets.   And they look very close to being identical, except one has a hole for an oil passage.  I am not talking about putting on a gasket backwards.  I was talking about two gaskets.  



Gimp, 40 hours is a very short period of time.   One of things you have to consider is the shaft shear point, which is essentially two "rivet"  looking things that hold the two pieces together.  It has already been mentioned that these are the pieces that shear causing the compressor to no longer be driven.   Some people decide to save money and just replace these rivet things with whatever they can find at Advance Auto.  Clearly, if this shear coupling was not replaced by a new one, or by one that came from a good overhaul facility (Jill or Coy) then you have no idea what was put in there.  Take a close look.  See if it looks like some home-brew repair.  



The next issue is your engine reversal on shut-down.  That is a very bad thing and needs to be halted and folks should be talking to you about that as a number one priority.  The fact that this is what might (or probably) was what caused this shear coupling to let go indicates there is some serious force involved here.  Another weak area in this engine design is the ACCESSORY SHAFT GEAR DRIVE.  If this darn thing manages to twist, the first indication will be your timing changing on the engine.  If it does get damaged, you are talking yanking the whole engine out.  So you need to get this reverse rotation on shut down resolved.   A couple of things that comes to mind are: 



1.  You're not running auto gas are you?  

2.  What kind of plugs and wires are you using?  

3.  Check the timing.  Even though you are shutting the mags OFF, ought of whack timing impacts plug temps which could cause a run-on.  

4. Engine running rich at idle... a whole slew of things can cause that.  

5.  Valve Lash.  



Are you letting the engine cool down before you shut it off?  Dennis, I know you have something to add here.  You're better on the engine than I am, and so are a number of other people.  



Mark

--

GeorgeCoy

Joined: 02 Dec 2010
Posts: 310

Posted: Fri Apr 24, 2015 9:48 am Post subject: Air Leak Advice

And just to confuse things, we have in inventory an alternator drive for

those who do not use air compressors and want a backup alternator IFR.

George Coy



--

mark.bitterlich(at)navy.m
Guest

Posted: Fri Apr 24, 2015 9:59 am Post subject: Air Leak Advice

Cool.



George, what is the proper name of the piece between the engine itself and the compressor drive assembly?  Is it a mounting BLOCK, or just what?  I called it an accessory drive, which is not really correct.  What is the name of that piece can you tell me please?



--

dsavarese0812(at)bellsout
Guest

Posted: Fri Apr 24, 2015 12:01 pm Post subject: Air Leak Advice

Shear coupling.

Dennis

        From: "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil>

 To: "yak-list(at)matronics.com" <yak-list(at)matronics.com> 

 Sent: Friday, April 24, 2015 12:59 PM

 Subject: RE: Re: Air Leak Advice

--> Yak-List message posted by: "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)>

Cool.

George, what is the proper name of the piece between the engine itself and the compressor drive assembly?  Is it a mounting BLOCK, or just what?  I called it an accessory drive, which is not really correct.  What is the name of that piece can you tell me please?

--

AcroGimp

Joined: 11 Jun 2013
Posts: 45
Location: San Diego, CA USA

Posted: Fri Apr 24, 2015 12:52 pm Post subject: Re: Air Leak Advice

Mark, I'll get back to the kick-back issue shortly.



I have all 6 bolts off and the banjo disconnected but one of the guys has mentioned recalling a sleeve or something between the compressor and the accessory case that can drop down into the case.



We're breaking for lunch but want to go ahead and get this thing pulled today since we are weathered out (yes, really, in San Diego, really).



Anything else we need be aware of when we go to pull it off?



Thanks in advance.



'Gimp

_________________
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW

AcroGimp

Joined: 11 Jun 2013
Posts: 45
Location: San Diego, CA USA

Posted: Fri Apr 24, 2015 1:19 pm Post subject: Re: Air Leak Advice

 	  mark.bitterlich(at)navy.m wrote: 	
		  



1.  You're not running auto gas are you?  

2.  What kind of plugs and wires are you using?  

3.  Check the timing.  Even though you are shutting the mags OFF, ought of whack timing impacts plug temps which could cause a run-on.  

4. Engine running rich at idle... a whole slew of things can cause that.  

5.  Valve Lash.  



Are you letting the engine cool down before you shut it off?  Dennis, I know you have something to add here.  You're better on the engine than I am, and so are a number of other people.  



Mark

-- 	
1 - 100LL only

2 - Auto conversion

3 - Seems to be running fine but will check

4 - Will check

5 - Would need to check



Has not been overly hot on shutdown but I could pay more attention.



'Gimp

_________________
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW

Viperdoc

Joined: 19 Apr 2014
Posts: 484
Location: 08A

Posted: Fri Apr 24, 2015 2:39 pm Post subject: Air Leak Advice

Mark, Mine never had one. I am putting One from Doug on now. Dennis, the Permatex anaerobic remains gummy like fuel lube. You can remove the gasket with it if done carefully.

Doc



Sent from my iPad



[quote] On Apr 24, 2015, at 12:16 PM, Bitterlich, Mark G CIV NAVAIR, WD <mark.bitterlich(at)navy.mil> wrote:

 

 

 

 Yes there one on the 50 Doc.  Maybe not on YOURS,  but on the three others I have had experience with ... yes.

 

 Mark

 

 

 --

_________________
Viperdoc

Viperdoc

Joined: 19 Apr 2014
Posts: 484
Location: 08A

Posted: Fri Apr 24, 2015 2:57 pm Post subject: Air Leak Advice

Mark,

Copy. When I pulled mine it was the entire compressor from the drive shaft as it mated to the accessory drive case. Have not pulled it apart otherwise but will look at it tomorrow in that I have a complete compressor in my spares stock. My parts catalog is in the cabinet in my hanger. I will look at it also.

By the way, my louvers are not even slotted (notched) for a trumpet to be mounted. Mine is a 74 also. There is a hole in the baffles for air to pass through though. 

Doc

Sent from my iPad

[quote] On Apr 24, 2015, at 5:39 PM, Roger Kemp <f16viperdoc(at)me.com> wrote:

 Mark, Mine never had one. I am putting One from Doug on now. Dennis, the Permatex anaerobic remains gummy like fuel lube. You can remove the gasket with it if done carefully.

 Doc

 Sent from my iPad

> On Apr 24, 2015, at 12:16 PM, Bitterlich, Mark G CIV NAVAIR, WD <mark.bitterlich(at)navy.mil> wrote:

> 

> 

> 

> Yes there one on the 50 Doc.  Maybe not on YOURS,  but on the three others I have had experience with ... yes.

> 

> Mark

> 

> 

> --

_________________
Viperdoc

AcroGimp

Joined: 11 Jun 2013
Posts: 45
Location: San Diego, CA USA

Posted: Fri Apr 24, 2015 5:44 pm Post subject: Re: Air Leak Advice

Got the compressor off, it was the shear coupling.  Verified compressor itself is still healthy (turns smoothly and pumps great).  Also verified gasket installed correctly and in great shape.



Will repair/replace the shear coupling and get a cooling horn for the compressor then re-install with new crush washers at banjo.



Plan to overhaul PRV and clean snot valve, reverse flush compressor to snot valve line while down.



Next issue will be check mag timing and idle mix.



Thanks all for the support so far, especially the Yak Collection guys here in San Diego for the assist.



More later.



'Gimp

_________________
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW

AcroGimp

Joined: 11 Jun 2013
Posts: 45
Location: San Diego, CA USA

Posted: Sun Apr 26, 2015 10:05 am Post subject: Re: Air Leak Advice

And now the later...



I do occasionally have a stumble on Mag 2 during run-up check that I had chalked up to occasional plug fouling during extended warm-up periods, usually clears up after a brief run-up.  Had not considered this related before, but now comes up with respect to the timing question brought up - possibly related?



Also, on shutdown , I run it up 65-70% for 20 seconds watching oil temp and CHT (only to see if green previously, will now pay more attention), then I pull throttle to idle, let it stabilize at around 28% idle but only for a second or two, then cage the mags.  As I got into the search function I see there is a recommendation to open the throttle as the mags are cut, or to cut the mags on oil pressure drop but before idle - what is the recommendation on the shutdown?



'Gimp

_________________
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW

mark.bitterlich(at)navy.m
Guest

Posted: Mon Apr 27, 2015 5:08 am Post subject: Air Leak Advice

Thanks Dennis, I knew I had the name wrong.



--

mark.bitterlich(at)navy.m
Guest

Posted: Mon Apr 27, 2015 6:12 am Post subject: Air Leak Advice

Ought to be a lot of different opinions here, but I bring my engine to idle (20% by the way), kill the mags, and when doing so open the throttle wide open until the prop stops and then pull back.  



I don't think that makes a hill of beans as to your issue though. 



How often do you change the plugs (I am thinking a carbon hot spot on the plugs maybe?).  I change mine once a year.  I never clean them, just replace them.  



What is the gap on the plugs?  (.018 - .022)



I'm running out of ideas to be honest.  We've covered most of the bases.  



Lastly.... Let me say that the M-14P engine is really NOT my field of expertise.  Like a lot of people, I am just repeating my own personal experiences although I do have a fair amount of wrench time on (older model) high performance automobile engines.  The simple fact though is that if the engine kicks back, it has to have fuel and a source of ignition, which COULD be a carbon hot spot.  I know I am going to catch hell for this, but I am going to offer you one last suggestion.  Go buy a QUART of Marvel Mystery Oil and pour the WHOLE QUART into your fuel.  Yes, I know.. this is well beyond recommended mixture ratios, but rest easy... I have done it many many MANY times with no damage on these engines, in fact one quart per 30 gallons!  Go fly and run the fool out of the engine.  Keep full throttle and about 90% for about 30 minutes, this assumes that you can keep oil and cylinder head temps out of the red!  But you want to get the engine turning and burning hard.  Let it slowly cool down in flight and then land and try it again.  ALSO bring your idle RPM down for 28% to about 20% before you do this.  Now land, cut it off and see what happens.   For the next month or so, run MMO at the recommended levels.  See if this helps.  Don't be surprised if the engine idles much better as well.  



I have my flame proof suit on, so others can have at it.      By the way, no, I am not wearing a FLIGHT SUIT (inside joke).  



  

Mark

--

dsavarese0812(at)bellsout
Guest

Posted: Mon Apr 27, 2015 6:27 am Post subject: Air Leak Advice

All good advice Mark.  MMO does work!



Only one comment - the idle on the M14 should be around 26%with the 

throttle all the way back.  At 20% many of the M14's will not continue 

to run.  Most will stumble and stall out.  The M14 maintenance manual 

does say 26%. How to properly set the idle is another subject.

Dennis



A. Dennis Savarese

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1



On 4/27/2015 9:07 AM, Bitterlich, Mark G CIV NAVAIR, WD wrote:

[quote] 



 Ought to be a lot of different opinions here, but I bring my engine to idle (20% by the way), kill the mags, and when doing so open the throttle wide open until the prop stops and then pull back.



 I don't think that makes a hill of beans as to your issue though.



 How often do you change the plugs (I am thinking a carbon hot spot on the plugs maybe?).  I change mine once a year.  I never clean them, just replace them.



 What is the gap on the plugs?  (.018 - .022)



 I'm running out of ideas to be honest.  We've covered most of the bases.



 Lastly.... Let me say that the M-14P engine is really NOT my field of expertise.  Like a lot of people, I am just repeating my own personal experiences although I do have a fair amount of wrench time on (older model) high performance automobile engines.  The simple fact though is that if the engine kicks back, it has to have fuel and a source of ignition, which COULD be a carbon hot spot.  I know I am going to catch hell for this, but I am going to offer you one last suggestion.  Go buy a QUART of Marvel Mystery Oil and pour the WHOLE QUART into your fuel.  Yes, I know.. this is well beyond recommended mixture ratios, but rest easy... I have done it many many MANY times with no damage on these engines, in fact one quart per 30 gallons!  Go fly and run the fool out of the engine.  Keep full throttle and about 90% for about 30 minutes, this assumes that you can keep oil and cylinder head temps out of the red!  But you want to get the engine turning and burning hard.  Let it sl!

   owly cool down in flight and then land and try it again.  ALSO bring your idle RPM down for 28% to about 20% before you do this.  Now land, cut it off and see what happens.   For the next month or so, run MMO at the recommended levels.  See if this helps.  Don't be surprised if the engine idles much better as well.



 I have my flame proof suit on, so others can have at it.      By the way, no, I am not wearing a FLIGHT SUIT (inside joke).



    

 Mark

 --

mark.bitterlich(at)navy.m
Guest

Posted: Mon Apr 27, 2015 6:37 am Post subject: Air Leak Advice

I strand corrected. 



My engine idles at about 21% smooth as a watch.  I must have gotten lucky.    



Was hoping you'd come in with better ideas actually. 

--

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