Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Compression

Matronics Email Lists Forum Index -> JabiruEngine-List

View previous topic :: View next topic

Author Message

aerobiz1(at)gmail.com
Guest

Posted: Mon Sep 12, 2011 6:49 am Post subject: Compression

Hi Bobby,



This sounds all too familiar. Â From memory, my Jab manual says that you need to pull the cylinders if the reading is 60/80 or less, but I would strongly suggest doing the test again but on a warm engine before getting too excited.

 



Cheers

Martin



On Tue, Sep 13, 2011 at 12:31 AM,  <BobbyPaulk(at)comcast.net (BobbyPaulk(at)comcast.net)> wrote:

 [quote] 



List,

I just finished a differential compression check of my 3300 for it's Conditional Inspection.

It has 125 hrs and has been broken in correctly and oil changed regularly. 

 3 cylinders have dropped to the low 60's over 80. #3, 4 & 5 are down from the mid 70's. #3 was below 70 at last conditional but now I have two more following suit. The #3 & 4Â  are not the hottest cylinders but #5 is second hottest. Engine was cold for 2 days at time of check. At this rate I don't know if it will make Top OH.

 The compression is beingÂ  lost through the rings as it can be heard thru the oil dipstick tube. Has anyone had a similar problem and is there any thing I can do about it. I am going to add Marvel Mystery to the fuel but I think that would be just a band aid on a more serious problem. How low should the compression get before I get alarmed??

 

Bobby Paulk

601 XL N131BP

Jabiru 3300 S/N 1141



  	  Quote: 	
		  



ist" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-List

tp://forums.matronics.com

_blank">http://www.matronics.com/contribution



	


[b]

- The Matronics JabiruEngine-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?JabiruEngine-List

Garth

Joined: 18 Feb 2010
Posts: 5

Posted: Mon Sep 12, 2011 7:33 am Post subject: Compression

From my experience, when doing both leakdown and compression checks, engine temperature can make a significant difference.  Jabiru says "warm to hot" for a leakdown test where the max 25% drop would apply.  You may not have an issue at all.

 

  

 Garth

 [quote]   

From: "BobbyPaulk(at)comcast.net" <BobbyPaulk(at)comcast.net>

To: jabiruengine-list-digest(at)matronics.com

Sent: Monday, September 12, 2011 10:31:19 AM

Subject: Compression



  #yiv439981971 p {margin:0;}   #yiv439981971 p {margin:0;}   #yiv439981971 p {margin:0;}  



List,

I just finished a differential compression check of my 3300 for it's Conditional Inspection.

It has 125 hrs and has been broken in correctly and oil changed regularly. 

3 cylinders have dropped to the low 60's over 80. #3, 4 & 5 are down from the mid 70's. #3 was below 70 at last conditional but now I have two more following suit. The #3 & 4  are not the hottest cylinders but #5 is second hottest. Engine was cold for 2 days at time of check. At this rate I don't know if it will make Top OH.

The compression is being  lost through the rings as it can be heard thru the oil dipstick tube. Has anyone had a similar problem and is there any thing I can do about it. I am going to add Marvel Mystery to the fuel but I think that would be just a band aid on a more serious problem. How low should the compression get before I get alarmed??



Bobby  Paulk

601 XL N131BP

Jabiru 3300 S/N 1141



 	  Quote: 	
		  



ist" rel=nofollow target=_blank>http://www.matronics.com/Navigator?JabiruEngine-List

et=_blank>http://forums.matronics.com

llow target=_blank>http://www.matronics.com/contribution



	






[b]

- The Matronics JabiruEngine-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?JabiruEngine-List

BARRY CHECK 6

Joined: 15 Mar 2011
Posts: 738

Posted: Mon Sep 12, 2011 9:14 am Post subject: Compression

Bobby:



MMO - Not to the fuel, but in to the CYLINDER.  Remove the plug, squirt MMO all over the inside of the cylinder (about 1 oz per cylinder) and let it sit over night.  If luck is on your side you may just free up some sticky rings.

 If you want to add some MMO to the oil - - - ONE HOUR BEFORE AN OIL CHANGE.  DO NOT RUN WITH MMO MORE THAN THAT.

You will see a cleaning of all internal parts.

MMO in the fuel is pretty much wasted.  The ratio of fuel is so high and the flow rate so fast that it really does nothing.   Been there - Done that.

 



Barry

On Mon, Sep 12, 2011 at 10:31 AM,  <BobbyPaulk(at)comcast.net (BobbyPaulk(at)comcast.net)> wrote:

[quote] 



List,

I just finished a differential compression check of my 3300 for it's Conditional Inspection.

 It has 125 hrs and has been broken in correctly and oil changed regularly. 

3 cylinders have dropped to the low 60's over 80. #3, 4 & 5 are down from the mid 70's. #3 was below 70 at last conditional but now I have two more following suit. The #3 & 4  are not the hottest cylinders but #5 is second hottest. Engine was cold for 2 days at time of check. At this rate I don't know if it will make Top OH.

 The compression is being  lost through the rings as it can be heard thru the oil dipstick tube. Has anyone had a similar problem and is there any thing I can do about it. I am going to add Marvel Mystery to the fuel but I think that would be just a band aid on a more serious problem. How low should the compression get before I get alarmed??

 

Bobby Paulk

601 XL N131BP

Jabiru 3300 S/N 1141



  	  Quote: 	
		  



ist" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-List

tp://forums.matronics.com

_blank">http://www.matronics.com/contribution



	


[b]

- The Matronics JabiruEngine-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?JabiruEngine-List

pete(at)usjabiru.com
Guest

Posted: Mon Sep 12, 2011 10:12 am Post subject: Compression

Bobby,

 

Before you start adding mysterious additives please do what the manual says and warm up your engine thoroughly before the compression check.  The engine should be as hot as practical to work with.  We can take any engine cold and get very inconsistent compression results!

 

Pete Krotje

Jabiru USA Sport Aircraft, LLC

931-680-2800

www.usjabiru.com

 

 

 

From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of FLYaDIVE

Sent: Monday, September 12, 2011 12:12 PM

To: jabiruengine-list(at)matronics.com

Subject: Re: Compression



 

Bobby:

 



MMO - Not to the fuel, but in to the CYLINDER.  Remove the plug, squirt MMO all over the inside of the cylinder (about 1 oz per cylinder) and let it sit over night.  If luck is on your side you may just free up some sticky rings.



If you want to add some MMO to the oil - - - ONE HOUR BEFORE AN OIL CHANGE.  DO NOT RUN WITH MMO MORE THAN THAT.



You will see a cleaning of all internal parts.



MMO in the fuel is pretty much wasted.  The ratio of fuel is so high and the flow rate so fast that it really does nothing.   Been there - Done that.



 



Barry



 

On Mon, Sep 12, 2011 at 10:31 AM, <BobbyPaulk(at)comcast.net (BobbyPaulk(at)comcast.net)> wrote:

List,

I just finished a differential compression check of my 3300 for it's Conditional Inspection.

It has 125 hrs and has been broken in correctly and oil changed regularly. 

3 cylinders have dropped to the low 60's over 80. #3, 4 & 5 are down from the mid 70's. #3 was below 70 at last conditional but now I have two more following suit. The #3 & 4  are not the hottest cylinders but #5 is second hottest. Engine was cold for 2 days at time of check. At this rate I don't know if it will make Top OH.

The compression is being  lost through the rings as it can be heard thru the oil dipstick tube. Has anyone had a similar problem and is there any thing I can do about it. I am going to add Marvel Mystery to the fuel but I think that would be just a band aid on a more serious problem. How low should the compression get before I get alarmed??



Bobby Paulk

601 XL N131BP

Jabiru 3300 S/N 1141

 	  Quote: 	
		    ist" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-Listtp://forums.matronics.com_blank">http://www.matronics.com/contribution 	


 

 	  Quote: 	
		     	
0 	  Quote: 	
		   	
1 	  Quote: 	
		   	
2 	  Quote: 	
		   	
3 	  Quote: 	
		   	
4 	  Quote: 	
		   	
5 	  Quote: 	
		   	
6 	  Quote: 	
		   	
7 	  Quote: 	
		   	
8 	  Quote: 	
		   	
9 	  Quote: 	
		  ist" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-List 	
0 	  Quote: 	
		  ist" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-List 	
1 	  Quote: 	
		  ist" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-List 	
2 	  Quote: 	
		  ist" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-List 	
3

   [quote][b]

- The Matronics JabiruEngine-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?JabiruEngine-List

zeprep251(at)aol.com
Guest

Posted: Mon Sep 12, 2011 1:08 pm Post subject: Compression

Bobby,

 Sometimes you can get the pressures up by slowly taking the piston over top center a few degrees and then bringing it back up to tdc WHILE HOLDING THE PROP FIRMLY THROUGH THIS MOTION!! It made a big difference on my Continental O200;s and IO470's

 G.Aman

    

  

     

  

    

     

  

     

  

    --

- The Matronics JabiruEngine-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?JabiruEngine-List

BobsV35B(at)aol.com
Guest

Posted: Mon Sep 12, 2011 2:15 pm Post subject: Compression

Good Afternoon Bobby,

  

 The Comparative Compression Check has been proven to have many faults. So  many such that Continental Motors now recommends that when the Compression gets  below the ancient 75 percent rule, further investigation be used before a  cylinder is pulled. 

  

 They specify that the valves be looked at via a Borescope. If the coloring  is equal all the way around. The valves are not being "burned" and can remain in  service.  

  

 In your case where you feel there is a ring problem, They recommend  that oil consumption be monitored. As long as such consumption is normal  (Whatever that is?) the engine is OK.

  

 CMC recommends that no cylinder be removed on strictly a low compression  number.

  

 See Continental Service Bulletin SB03-3.

  

 My take is that the same principles will apply to the Jabiru.

  

 Happy Skies,

  

 Old Bob

 Stearman N3977A

 Downers Grove, IL

 LL22

  

  In a message dated 9/12/2011 4:08:23 P.M. Central Daylight Time,  zeprep251(at)aol.com writes:

  	  Quote: 	
		  Bobby,

Sometimes you can get the pressures up by slowly taking    the piston over top center a few degrees and then bringing it back up to tdc    WHILE HOLDING THE PROP FIRMLY THROUGH THIS MOTION!! It made a big difference    on my Continental O200;s and IO470's

G.Aman

   



   



   

   



   



   -----Original    Message-----

From: BobbyPaulk <BobbyPaulk(at)comcast.net>

To:    jabiruengine-list-digest    <jabiruengine-list-digest(at)matronics.com>

Sent: Mon, Sep 12, 2011    11:11 am

Subject: Compression



      #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 td{color: black;} #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 p { margin: 0; }       #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 td{color: black;} #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 p { margin: 0; }       #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 td{color: black;} #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 p { margin: 0; }    



List,

I    just finished a differential compression check of my 3300 for it's Conditional    Inspection.

It has 125 hrs and has been broken in correctly and oil changed    regularly. 

3 cylinders have dropped to the low 60's over 80. #3, 4 & 5    are down from the mid 70's. #3 was below 70 at last conditional but now I have    two more following suit. The #3 & 4  are not the hottest cylinders    but #5 is second hottest. Engine was cold for 2 days at time of check. At this    rate I don't know if it will make Top OH.

The compression is being     lost through the rings as it can be heard thru the oil dipstick tube. Has    anyone had a similar problem and is there any thing I can do about it. I am    going to add Marvel Mystery to the fuel but I think that would be just a band    aid on a more serious problem. How low should the compression get before I get    alarmed??



Bobby Paulk

601 XL N131BP

Jabiru 3300 S/N    1141

	


 [quote][b]

- The Matronics JabiruEngine-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?JabiruEngine-List

BobsV35B(at)aol.com
Guest

Posted: Mon Sep 12, 2011 2:22 pm Post subject: Compression

HMMM---

  

 One more thing Bobby,

  

 I should have mentioned that the Borescope inspection should include  looking at the cylinder wall to check for scratches which may indicate a  broken ring.

  

 Happy Skies.

  

 Old Bob

 AKA

 Bob Siegfried

 Ancient Aviator

  

  In a message dated 9/12/2011 5:15:55 P.M. Central Daylight Time,  BobsV35B(at)aol.com writes:

  	  Quote: 	
		     Good Afternoon Bobby,

    

   The Comparative Compression Check has been proven to have many faults. So    many such that Continental Motors now recommends that when the Compression    gets below the ancient 75 percent rule, further investigation be used before a    cylinder is pulled. 

    

   They specify that the valves be looked at via a Borescope. If the    coloring is equal all the way around. The valves are not being "burned" and    can remain in service.  

    

   In your case where you feel there is a ring problem, They recommend    that oil consumption be monitored. As long as such consumption is normal    (Whatever that is?) the engine is OK.

    

   CMC recommends that no cylinder be removed on strictly a low compression    number.

    

   See Continental Service Bulletin SB03-3.

    

   My take is that the same principles will apply to the Jabiru.

    

   Happy Skies,

    

   Old Bob

   Stearman N3977A

   Downers Grove, IL

   LL22

    

      In a message dated 9/12/2011 4:08:23 P.M. Central Daylight Time,    zeprep251(at)aol.com writes:

    	  Quote: 	
		  Bobby,

Sometimes you can get the pressures up by slowly taking      the piston over top center a few degrees and then bringing it back up to tdc      WHILE HOLDING THE PROP FIRMLY THROUGH THIS MOTION!! It made a big difference      on my Continental O200;s and IO470's

G.Aman

     



     



     

     



     



     -----Original      Message-----

From: BobbyPaulk <BobbyPaulk(at)comcast.net>

To:      jabiruengine-list-digest      <jabiruengine-list-digest(at)matronics.com>

Sent: Mon, Sep 12, 2011      11:11 am

Subject: Compression



          #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 td{color: black;} #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 p { margin: 0; }           #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 td{color: black;} #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 p { margin: 0; }           #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 td{color: black;} #AOLMsgPart_1_79a14479-9575-491a-9f92-315c8cc51652 p { margin: 0; }      



List,

I      just finished a differential compression check of my 3300 for it's      Conditional Inspection.

It has 125 hrs and has been broken in correctly      and oil changed regularly. 

3 cylinders have dropped to the low 60's over      80. #3, 4 & 5 are down from the mid 70's. #3 was below 70 at last      conditional but now I have two more following suit. The #3 & 4  are      not the hottest cylinders but #5 is second hottest. Engine was cold for 2      days at time of check. At this rate I don't know if it will make Top      OH.

The compression is being  lost through the rings as it can be      heard thru the oil dipstick tube. Has anyone had a similar problem and is      there any thing I can do about it. I am going to add Marvel Mystery to the      fuel but I think that would be just a band aid on a more serious problem.      How low should the compression get before I get alarmed??



Bobby      Paulk

601 XL N131BP

Jabiru 3300 S/N      1141



	


	


 [quote][b]

- The Matronics JabiruEngine-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?JabiruEngine-List

Display posts from previous:

	Matronics Email Lists Forum Index -> JabiruEngine-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum