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

Oil pressure

Matronics Email Lists Forum Index -> Europa-List

View previous topic :: View next topic

Author Message

wdaniell(at)etb.net.co
Guest

Posted: Mon Apr 23, 2007 7:18 am Post subject: Oil pressure

I know that I have asked this before but I wonder if everyone could rack their brains.  

   

My motor starts fine the pressure goes up to 5.5 bar for about 2-4 minutes.  

   

It then falls with not loss of rpm to 1.5 bar for about 2-5 minutes.  

   

It then goes back up to 5.5 and stays there without a problem.  

   

The oil pressure sender is working fine and is the gauge – I have tested them both.  The engine runs smooth and produces sufficient power.  I run avgas because the premium mogas here is 95 or lower octane.  

   

On a hot day the pressure drop is minimal on start up.  So I am thinking that maybe this has something to do with viscosity.  Perhaps even what Ira mentioned - lead accumulation in the oil tank.   

   

Any ideas as to the cause?  

How much damage will this do?  Clearly this is not ideal but it could be one of those problems where the “solution” ends up being always out of reach.   

   

Will  

Colombia  

   

       [quote][b]

Gilles.Thesee(at)ac-greno
Guest

Posted: Mon Apr 23, 2007 7:56 am Post subject: Oil pressure

William Daniell a écrit :



 	  Quote: 	
		   My motor starts fine the pressure goes up to 5.5 bar for about 2-4 

 minutes.



 It then falls with not loss of rpm to 1.5 bar for about 2-5 minutes.



 It then goes back up to 5.5 and stays there without a problem.



 The oil pressure sender is working fine and is the gauge – I have 

 tested them both. The engine runs smooth and produces sufficient 

 power. I run avgas because the premium mogas here is 95 or lower octane.



 On a hot day the pressure drop is minimal on start up. So I am 

 thinking that maybe this has something to do with viscosity. Perhaps 

 even what Ira mentioned - lead accumulation in the oil tank.



 Any ideas as to the cause?



 How much damage will this do? Clearly this is not ideal but it could 

 be one of those problems where the “solution” ends up being always out 

 of reach.

William,
	




If your engine is a Rotax 91X, then you might wish to review the SB on 

oil starvation on startup.

Yes it may have something to do with viscosity when cold, and oil pump 

starvation due to length/diameter/routing/obstruction of oil line. 

Especially as you seem to say that the problem is less obvious on a hot day.



FWIW,

Regards,

Gilles

http://contrails.free.fr

rehn(at)rockisland.com
Guest

Posted: Mon Apr 23, 2007 8:29 am Post subject: Oil pressure

You could test the oil system per SI-912-005. This would help determine problems of suctions and pressures. Also you might try purging the system per SI-04-1997. This is relatively easy to do and would insure there isn’t air in your system. Third check the oil relief ball and spring for wear and contamination another easy check.   

Jerry   

         

  

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of William Daniell

 Sent: Monday, April 23, 2007 8:18 AM

 To: europa-list(at)matronics.com

 Subject: Oil pressure  

  

   

I know that I have asked this before but I wonder if everyone could rack their brains.  

   

My motor starts fine the pressure goes up to 5.5 bar for about 2-4 minutes.  

   

It then falls with not loss of rpm to 1.5 bar for about 2-5 minutes.  

   

It then goes back up to 5.5 and stays there without a problem.  

   

The oil pressure sender is working fine and is the gauge – I have tested them both.  The engine runs smooth and produces sufficient power.  I run avgas because the premium mogas here is 95 or lower octane.  

   

On a hot day the pressure drop is minimal on start up.  So I am thinking that maybe this has something to do with viscosity.  Perhaps even what Ira mentioned - lead accumulation in the oil tank.   

   

Any ideas as to the cause?  

How much damage will this do?  Clearly this is not ideal but it could be one of those problems where the “solution” ends up being always out of reach.   

   

Will  

Colombia  

    	  Quote: 	
		    http://www.matronics.com/Navigator?Europa-List 	
0 	  Quote: 	
		   	
1 	  Quote: 	
		   	
2 	  Quote: 	
		   	
3 	  Quote: 	
		   	
4

        [quote][b]

wdaniell(at)etb.net.co
Guest

Posted: Mon Apr 23, 2007 8:53 am Post subject: Oil pressure

Sorry, I forgot to add that we have purged the system as per the latest rotax bulletin and also checked the regulator.  

   

Correct me if I am wrong but I have seen “burping” the system.  I have always assumed that this was rotating the prop in the correct direction with the cap of the oil tank off until you get the burping sound.  Is this correct?  

   

The only thing that I can think of is that it is some kind of restriction in the “circuit” which ceases to be a restriction once the oil is less viscous (warmed up).  

   

Will  

         

  

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Jerry Rehn

 Sent: Monday, April 23, 2007 11:27

 To: europa-list(at)matronics.com

 Subject: RE: Oil pressure  

  

   

You could test the oil system per SI-912-005. This would help determine problems of suctions and pressures. Also you might try purging the system per SI-04-1997. This is relatively easy to do and would insure there isn’t air in your system. Third check the oil relief ball and spring for wear and contamination another easy check.   

Jerry   

         

  

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of William Daniell

 Sent: Monday, April 23, 2007 8:18 AM

 To: europa-list(at)matronics.com

 Subject: Oil pressure  

  

   

I know that I have asked this before but I wonder if everyone could rack their brains.  

   

My motor starts fine the pressure goes up to 5.5 bar for about 2-4 minutes.  

   

It then falls with not loss of rpm to 1.5 bar for about 2-5 minutes.  

   

It then goes back up to 5.5 and stays there without a problem.  

   

The oil pressure sender is working fine and is the gauge – I have tested them both.  The engine runs smooth and produces sufficient power.  I run avgas because the premium mogas here is 95 or lower octane.  

   

On a hot day the pressure drop is minimal on start up.  So I am thinking that maybe this has something to do with viscosity.  Perhaps even what Ira mentioned - lead accumulation in the oil tank.   

   

Any ideas as to the cause?  

How much damage will this do?  Clearly this is not ideal but it could be one of those problems where the “solution” ends up being always out of reach.   

   

Will  

Colombia  

    	  Quote: 	
		     	
[/b]http://www.matronics.com/Navigator?Europa-List 	  Quote: 	
		  [b] 	
http://forums.matronics.com[/b] 	  Quote: 	
		  [b]    	
0 	  Quote: 	
		   	
1 	  Quote: 	
		   	
2 	  Quote: 	
		   	
3 	  Quote: 	
		   	
4 	  Quote: 	
		   	
5 	  Quote: 	
		   	
6 	  Quote: 	
		   	
7 	  Quote: 	
		   	
8 	  Quote: 	
		   	
9 	  Quote: 	
		   	
0

       [quote][b]

wdaniell(at)etb.net.co
Guest

Posted: Mon Apr 23, 2007 8:55 am Post subject: Oil pressure

Gilles

Thank you.  Mmmmm, this sounds like an interesting route.



I think a change of oil line(s) would be an interesting step and non

invasive.  Any ideas about which line to start with?



Will



--

terrys(at)cisco.com
Guest

Posted: Mon Apr 23, 2007 11:33 am Post subject: Oil pressure

Hi Will,

  

 When we first got our engine running we checked the oil  pump 'suction' as was called out in the Europa build manual in the  engine provisioning(?) section.  We found the suction to be too great, I'm  at work now and don't remember the exact numbers.  We observed that the  Europa supplied oil line from the oil cooler to oil pump inlet had a molded 90  deg bend in it, a few inches before the pump inlet, and suspected that the oil  line was partially collapsing at this bend.  We replaced the molded elbow  with a short section of 90 deg aluminum tubing.  A subsequent oil pump  suction test showed a drop in suction, bringing if fairly close to the  specified maximum value.  The suction values were, as expected, greatest  when the oil was cold, and dropped off as the oil warmed up.  I would  expect that the elbow in the oil line feeding the pump inlet would be most  likely to collapse when the oil is cold and the suction is at its  greatest.

  

 At the time (about six years ago) we sent emails to the  Europa group asking what values others were getting in their suction tests, but  received no responses from anyone who had performed the test.  If there is  anyone who has performed the suction test, I would be interested in hearing  their numbers.

  

 regards,

 Terry Seaver

 A135/N125TD

 Monowheel XS with 912S, Whirlwind  prop



   From: owner-europa-list-server(at)matronics.com  [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of William  Daniell

Sent: Monday, April 23, 2007 9:53 AM

To:  europa-list(at)matronics.com

Subject: RE: Oil  pressure

 

  

Sorry, I forgot to add  that we have purged the system as per the latest rotax bulletin and also checked  the regulator. 

  

Correct me if I am  wrong but I have seen “burping” the system.  I have always assumed that  this was rotating the prop in the correct direction with the cap of the oil tank  off until you get the burping sound.  Is this  correct? 

  

The only thing that I  can think of is that it is some kind of restriction in the “circuit” which  ceases to be a restriction once the oil is less viscous (warmed  up). 

  

Will 

     

 

From:  owner-europa-list-server(at)matronics.com  [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Jerry Rehn

Sent: Monday, April 23, 2007  11:27

To:  europa-list(at)matronics.com

Subject: RE: Oil  pressure

 

  

You could test the oil  system per SI-912-005. This would help determine problems of suctions and  pressures. Also you might try purging the system per SI-04-1997. This is  relatively easy to do and would insure there isn’t air in your system. Third  check the oil relief ball and spring for wear and contamination another easy  check.  

Jerry   

     

 

From:  owner-europa-list-server(at)matronics.com  [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of William Daniell

Sent: Monday, April 23, 2007 8:18  AM

To:  europa-list(at)matronics.com

Subject: Oil  pressure

 

  

I know that I have  asked this before but I wonder if everyone could rack their  brains. 

  

My motor starts fine  the pressure goes up to 5.5 bar for about 2-4  minutes. 

  

It then falls with not  loss of rpm to 1.5 bar for about 2-5 minutes. 

  

It then goes back up to  5.5 and stays there without a problem. 

  

The oil pressure sender  is working fine and is the gauge – I have tested them both.  The engine  runs smooth and produces sufficient power.  I run avgas because the premium  mogas here is 95 or lower octane. 

  

On a hot day the  pressure drop is minimal on start up.  So I am thinking that maybe this has  something to do with viscosity.  Perhaps even what Ira mentioned - lead  accumulation in the oil tank.  

  

Any ideas as to the  cause? 

How much damage will  this do?  Clearly this is not ideal but it could be one of those problems  where the “solution” ends up being always out of reach.   

  

Will 

Colombia 

 [/b][b]

  [quote][b]

wdaniell(at)etb.net.co
Guest

Posted: Mon Apr 23, 2007 12:53 pm Post subject: Oil pressure

Excellent – thanks.  

   

I will look at this and report back  

   

Will  

         

  

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Terry Seaver (terrys)

 Sent: Monday, April 23, 2007 14:29

 To: europa-list(at)matronics.com

 Subject: RE: Oil pressure  

  

   

Hi Will,  

   

When we first got our engine running we checked the oil pump 'suction' as was called out in the Europa build manual in the engine provisioning(?) section.  We found the suction to be too great, I'm at work now and don't remember the exact numbers.  We observed that the Europa supplied oil line from the oil cooler to oil pump inlet had a molded 90 deg bend in it, a few inches before the pump inlet, and suspected that the oil line was partially collapsing at this bend.  We replaced the molded elbow with a short section of 90 deg aluminum tubing.  A subsequent oil pump suction test showed a drop in suction, bringing if fairly close to the specified maximum value.  The suction values were, as expected, greatest when the oil was cold, and dropped off as the oil warmed up.  I would expect that the elbow in the oil line feeding the pump inlet would be most likely to collapse when the oil is cold and the suction is at its greatest.  

   

At the time (about six years ago) we sent emails to the Europa group asking what values others were getting in their suction tests, but received no responses from anyone who had performed the test.  If there is anyone who has performed the suction test, I would be interested in hearing their numbers.  

   

regards,  

Terry Seaver  

A135/N125TD  

Monowheel XS with 912S, Whirlwind prop  

       

  

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of William Daniell

 Sent: Monday, April 23, 2007 9:53 AM

 To: europa-list(at)matronics.com

 Subject: RE: Oil pressure  

Sorry, I forgot to add that we have purged the system as per the latest rotax bulletin and also checked the regulator.  

   

Correct me if I am wrong but I have seen “burping” the system.  I have always assumed that this was rotating the prop in the correct direction with the cap of the oil tank off until you get the burping sound.  Is this correct?  

   

The only thing that I can think of is that it is some kind of restriction in the “circuit” which ceases to be a restriction once the oil is less viscous (warmed up).  

   

Will  

         

  

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Jerry Rehn

 Sent: Monday, April 23, 2007 11:27

 To: europa-list(at)matronics.com

 Subject: RE: Oil pressure  

  

   

You could test the oil system per SI-912-005. This would help determine problems of suctions and pressures. Also you might try purging the system per SI-04-1997. This is relatively easy to do and would insure there isn’t air in your system. Third check the oil relief ball and spring for wear and contamination another easy check.   

Jerry   

         

  

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of William Daniell

 Sent: Monday, April 23, 2007 8:18 AM

 To: europa-list(at)matronics.com

 Subject: Oil pressure  

  

   

I know that I have asked this before but I wonder if everyone could rack their brains.  

   

My motor starts fine the pressure goes up to 5.5 bar for about 2-4 minutes.  

   

It then falls with not loss of rpm to 1.5 bar for about 2-5 minutes.  

   

It then goes back up to 5.5 and stays there without a problem.  

   

The oil pressure sender is working fine and is the gauge – I have tested them both.  The engine runs smooth and produces sufficient power.  I run avgas because the premium mogas here is 95 or lower octane.  

   

On a hot day the pressure drop is minimal on start up.  So I am thinking that maybe this has something to do with viscosity.  Perhaps even what Ira mentioned - lead accumulation in the oil tank.   

   

Any ideas as to the cause?  

How much damage will this do?  Clearly this is not ideal but it could be one of those problems where the “solution” ends up being always out of reach.   

   

Will  

Colombia  

    	  Quote: 	
		   	
[/b][quote][b] http://www.matronics.com/Navigator?Europa-List 	  Quote: 	
		  [b] 	
0[quote] 	  Quote: 	
		  [b] 	
1[quote] 	  Quote: 	
		  [b] 	
2[quote] 	  Quote: 	
		  [b] 	
3[quote] 	  Quote: 	
		  [b] 	
4

       [quote][b]

ami(at)mcfadyean.freeserv
Guest

Posted: Mon Apr 23, 2007 1:35 pm Post subject: Oil pressure

<<If there is anyone who  has performed the suction test, I would be interested in hearing their  numbers>>

  

 -0.1 bar (max allowable is -0.3 bar)  measured on a 912S. Hose is the 'standard' Rotax-supplied Conti (routed across  the top of the engine) and oil tank fittings

  

 The barbed push-on inlet fitting  on the oil pump had been replaced  with a nipple and 180 degree  preformed fitting on the engine  (the delivery hose 'approaches' under the  gearbox from the S'bd side of the engine and therefore has to turn back on  itself).

  

 It surprises me that this test is not  more popular.

  

 Duncan McF.

 [quote]   ---

danny shepherd

Joined: 27 Jan 2006
Posts: 117
Location: north Wales, United Kingdom

Posted: Mon Apr 30, 2007 6:45 am Post subject: oil pressure

Hi All,

          Can some one tell me if its normal for the oil pressure to 

drop when revving up the engine. After start up the pressure immediately 

reaches 4.5 bar, but when I throttle up it drops to 2.5. Is this strange 

/ normal ? With all the talk about Rotax not liking oil starvation  its 

a bit concerning .



Cheers Danny

terrys(at)cisco.com
Guest

Posted: Mon Apr 30, 2007 9:28 am Post subject: oil pressure

Hi Danny,



As I recall, we noticed a similar thing with our 912S, early on.  We

noticed that our oil pump inlet 'suction' was too high and suspected

that the 90 deg bend in the molded inlet oil line was collapsing (this

is the line from the oil cooler to the oil pump inlet).  We replaced the

bend in the oil line with a short aluminum elbow, which reduced our

suction at the oil pump inlet.  As I recall, this also reduced the drop

in oil pressure at higher rpms.  The bend I am talking about is the one

just a few inches (maybe 4 inches?) from the oil pump inlet.



Regards,

Terry Seaver

A135 / N135TD

XS monowheel with 912S, Airmaster prop

 



--

william(at)wrmills.plus.c
Guest

Posted: Mon Apr 30, 2007 9:02 pm Post subject: oil pressure

I had the same symptoms, Danny, when my 912S was new.  The Rotax oil 

pressure gauge also twitched violently, before settling down at about 2.5 

bar.  However, 350 hours later, it no longer twitches and it runs at about 

3.75 bar when hot in the cruise.  I can only imagine the pressure relief 

valve ball has eventually bedded into its seat.  BTW, my previous engine was 

a 912 (80 HP) which ran at 4 bar constantly all its life (800 hrs) and the 

oil pipes and cooler were exactly the same from one engine to the other, so 

I don't believe any of the pipes were collapsing due to suction.

I hope that helps,

William



---

danny shepherd

Joined: 27 Jan 2006
Posts: 117
Location: north Wales, United Kingdom

Posted: Tue May 01, 2007 12:37 am Post subject: oil pressure

Thanks Pete / Terry / William,  I'll get back in the hangar (big shed) 

latter this afternoon and check the pipes.



Cheers Danny G-c.e.r.i

willie.harrison(at)tinyon
Guest

Posted: Tue May 01, 2007 1:10 am Post subject: oil pressure

Me too. I've observed the same and I'd been assuming - probably  

wrongly - that it was due to a pressure regulating vale spilling  

excess pressure at higher rpm.



On 1 May 2007, at 09:28, danny(at)mcwalterscafe.co.uk wrote:



 	  Quote: 	
		   

 <danny(at)mcwalterscafe.co.uk>



 Thanks Pete / Terry / William,  I'll get back in the hangar (big  

 shed) latter this afternoon and check the pipes.



 Cheers Danny G-c.e.r.i

Display posts from previous:

	Matronics Email Lists Forum Index -> Europa-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