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High EGT cyl 5 -running out of ideas

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ple190

Joined: 03 Sep 2010
Posts: 23
Location: Australia

Posted: Fri Apr 27, 2012 2:26 pm Post subject: High EGT cyl 5 -running out of ideas

I,m running a 3300 in a Lightning .Main jet 255 needle 290. My main concern is No 5 cylinder. At best econ (2800 rpm) ie just prior to needle to main changeover No. 5 will peak around 760 Deg C (1400F) (at) 2500ft  OAT 10degC  Thats about 50-60 deg C above all the others. The numbers are better up higher as expected



All the CHT's are good 120-130 C  as are the  oil T's & P's and the engine run well, smooth through entire range



Normal cruise RPM of about 2900 is fine, EGT comes done to low 700's

On descent if i maintain 2900rpm no 5 EGT will again rise to 760-770 C



Should I be concerned ?? 



I have tried the following to resolve

1.carb tilt

2.intake vane

3.neddle jet increase 285-290

4.Checked for leaks in induction pipes/carby etc

5.swapped Sensors (reading was confirmed)



Any ideas ??

BobsV35B(at)aol.com
Guest

Posted: Fri Apr 27, 2012 3:21 pm Post subject: High EGT cyl 5 -running out of ideas

Good Evening plge190,

  

 As a general rule, the actual temperature of the exhaust gas means very  little. What you really want to know is at what point it reaches peak in  relation to when other cylinders reach peak. If they all reach peak at the same  fuel flow, the mixture is perfectly balanced through out every cylinder. 

  

 The actual temperature can vary widely based on very small differences in  probe placement.  If the cylinders all peak at fairly near the same fuel  flow, forget about it!

  

 Al Hundere. the guru who got us all looking at EGTs, refused to list the  actual temperature as it is not at all pertinent to what we are trying to  do.

  

 Happy Skies,

  

 Old Bob

  

  In a message dated 4/27/2012 5:27:18 P.M. Central Daylight Time,  plge190(at)optusnet.com.au writes:

  	  Quote: 	
		  -->    JabiruEngine-List message posted by: "ple190"    <plge190(at)optusnet.com.au>



I,m running a 3300 in a Lightning .Main    jet 255 needle 290. My main concern is No 5 cylinder. At best econ (2800 rpm)    ie just prior to needle to main changeover No. 5 will peak around 760 Deg C    (1400F) (at) 2500ft  OAT 10degC  Thats about 50-60 deg C above all the    others. The numbers are better up higher as expected



All the CHT's are    good 120-130 C  as are the  oil T's & P's and the engine run    well, smooth through entire range



Normal cruise RPM of about 2900 is    fine, EGT comes done to low 700's

On descent if i maintain 2900rpm no 5 EGT    will again rise to 760-770 C



Should I be concerned ?? 



I have    tried the following to resolve

1.carb tilt

2.intake vane

3.neddle jet    increase 285-290

4.Checked for leaks in induction pipes/carby    etc

5.swapped Sensors (reading was confirmed)



Any ideas    ??





	


 [quote][b]

BARRY CHECK 6

Joined: 15 Mar 2011
Posts: 738

Posted: Fri Apr 27, 2012 3:44 pm Post subject: High EGT cyl 5 -running out of ideas

Questions:  

1 - Are all the EGT probes the same distance from the exhaust port flange?

2 - Is there any cooling air directed on the other probes, or air blockage on #5?

 3 - Are there any abrupt bends in #5 that do not exist in the other exhaust headers?

Barry

 On Fri, Apr 27, 2012 at 6:26 PM, ple190 <plge190(at)optusnet.com.au (plge190(at)optusnet.com.au)> wrote:

[quote] --> JabiruEngine-List message posted by: "ple190" <plge190(at)optusnet.com.au (plge190(at)optusnet.com.au)>

 

 I,m running a 3300 in a Lightning .Main jet 255 needle 290. My main concern is No 5 cylinder. At best econ (2800 rpm) ie just prior to needle to main changeover No. 5 will peak around 760 Deg C (1400F) (at) 2500ft  OAT 10degC  Thats about 50-60 deg C above all the others. The numbers are better up higher as expected

  

 All the CHT's are good 120-130 C  as are the  oil T's & P's and the engine run well, smooth through entire range

 

 Normal cruise RPM of about 2900 is fine, EGT comes done to low 700's

 On descent if i maintain 2900rpm no 5 EGT will again rise to 760-770 C

 

 Should I be concerned ??

 

 I have tried the following to resolve

 1.carb tilt

 2.intake vane

 3.neddle jet increase 285-290

 4.Checked for leaks in induction pipes/carby etc

 5.swapped Sensors (reading was confirmed)

 

 Any ideas ??

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=371932#371932

 

 

 

 

 

 

 

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ple190

Joined: 03 Sep 2010
Posts: 23
Location: Australia

Posted: Fri Apr 27, 2012 5:22 pm Post subject: Re: High EGT cyl 5 -running out of ideas

Thanks for the input guys.

Old BOB ---The problem with the Jab and bing carb is no mixture control so you have no way of knowing if your near peak EGT so I dont know if No 5 if at/near or above peak EGT?



Barry --All the probs are in the same spot from the port. No 5 was a bit closer so i moved it to match the others with no change ?

I will check if any cold air is being forced onto the senor

Paul

nick(at)flylightning.net
Guest

Posted: Fri Apr 27, 2012 5:40 pm Post subject: High EGT cyl 5 -running out of ideas

What SN lightning you have?

You can lean the bing with a little device called a HACman. We have been using them on our Lightnings since 2008.

Also we do have a 4 way intake splitter installed at the carb throat. That seems to get the egts all in line.

What prop are you running. We normally run 62fk58s here and use 250 main and 276-280 needles. Also engine SN would help and clean up kit?



Thanks

Nick



Sent from my pocket 



On Apr 27, 2012, at 8:22 PM, "ple190" <plge190(at)optusnet.com.au> wrote:



 	  Quote: 	
		   

 

 Thanks for the input guys.

 Old BOB ---The problem with the Jab and bing carb is no mixture control so you have no way of knowing if your near peak EGT so I dont know if No 5 if at/near or above peak EGT?

 

 Barry --All the probs are in the same spot from the port. No 5 was a bit closer so i moved it to match the others with no change ?

 I will check if any cold air is being forced onto the senor

 Paul

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=371949#371949

BARRY CHECK 6

Joined: 15 Mar 2011
Posts: 738

Posted: Fri Apr 27, 2012 5:42 pm Post subject: High EGT cyl 5 -running out of ideas

Very good Paul.

I have lots of experience with Lycoming and I know the intake pipes are a total mismatch.  That is one major reason why they can not get even EGT readings.

 If your CHT is fairly uniform then I would not worry too much.

Have you tried a HOTTER spark plug on #5?

Why hotter - Because if the fuel is not completely burning in the cylinder then it will burn in the exhaust pipe raising the EGT.

 What Old Bob says is also VERY true.  You do not know if you have reached Peak EGT or the other cylinders are below #5.

Keep the group posted,

 Barry



On Fri, Apr 27, 2012 at 9:22 PM, ple190 <plge190(at)optusnet.com.au (plge190(at)optusnet.com.au)> wrote:

 [quote]--> JabiruEngine-List message posted by: "ple190" <plge190(at)optusnet.com.au (plge190(at)optusnet.com.au)>

  

 Thanks for the input guys.

 Old BOB ---The problem with the Jab and bing carb is no mixture control so you have no way of knowing if your near peak EGT so I dont know if No 5 if at/near or above peak EGT?

 

 Barry --All the probs are in the same spot from the port. No 5 was a bit closer so i moved it to match the others with no change ?

 I will check if any cold air is being forced onto the senor

 Paul

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=371949#371949

 

 

 

 

 

 

 

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

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 [b]

BARRY CHECK 6

Joined: 15 Mar 2011
Posts: 738

Posted: Fri Apr 27, 2012 5:44 pm Post subject: High EGT cyl 5 -running out of ideas

Paul:

I had one more idea.  You could Port & Polish the intake and exhaust ports to gain an even flow and you will gain a few more HP too.

 



Barry



On Fri, Apr 27, 2012 at 9:22 PM, ple190 <plge190(at)optusnet.com.au (plge190(at)optusnet.com.au)> wrote:

 [quote]--> JabiruEngine-List message posted by: "ple190" <plge190(at)optusnet.com.au (plge190(at)optusnet.com.au)>

  

 Thanks for the input guys.

 Old BOB ---The problem with the Jab and bing carb is no mixture control so you have no way of knowing if your near peak EGT so I dont know if No 5 if at/near or above peak EGT?

 

 Barry --All the probs are in the same spot from the port. No 5 was a bit closer so i moved it to match the others with no change ?

 I will check if any cold air is being forced onto the senor

 Paul

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=371949#371949

 

 

 

 

 

 

 

 ===========

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

 ===========

 http://forums.matronics.com

 ===========

 le, List Admin.

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

 ===========

 

 

 

 [b]

ple190

Joined: 03 Sep 2010
Posts: 23
Location: Australia

Posted: Fri Apr 27, 2012 6:57 pm Post subject: Re: High EGT cyl 5 -running out of ideas

Thanks Nick and Barry

Nick I have kit 104 with wheel fairing /pants installed and I'm running a 62FK58 prop

The eng is   s/no 2246 so hyd lifter but not  the latest induction manifold

Also I have a  way splitter in the air box outlet which did help and have also tried one in the smooth pipe thats on the carby intake and it didn't make any difference.

My understanding of the Hackman is its a leaning device ? so not sure if this will help ?



Barry do you have a part no for a hotter plug ? its worth a try

ple190

Joined: 03 Sep 2010
Posts: 23
Location: Australia

Posted: Fri Apr 27, 2012 7:27 pm Post subject: Re: High EGT cyl 5 -running out of ideas

Nick- do you guys use the throttle extension on the carby ? I am and it limits the amount of twist you can get. 



Also looking at the jets you are using Nick may I'm running too rich and as Barry said getting a burn in the exhaust pipe? I did increase the needle from 285 to 290 and it didn't help maybe even worse. I guess with the hackman I can lean out and see what happens. At least I'll know how close to peak I am.

 It runs well just don't want to do any damage !!



checked all the plugs the other day and they are all quite black and No. 5 is the same as the others ?

I miss the good old days of steam gauges--or lack there of

 "ignorance is bliss"

Paul

BARRY CHECK 6

Joined: 15 Mar 2011
Posts: 738

Posted: Fri Apr 27, 2012 9:29 pm Post subject: High EGT cyl 5 -running out of ideas

Paul:

The NGK Spark plug - D9EA is what is supplied with the engine... I believe...

Below is the web site for NGK and there is a lot of info supplied.  One statement they make is an increase in heat range is a 70 to 100 Deg C increase.  

 So, start by reading the chart on the site for Plug Condition (Reading the plug).  Then compare the plugs on the cylinders.  

Then pick a heat range that a now educated guess would say should give you the best results.

 



Spark Plug Color/Condition:

http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp 

 



Heat Range Info:

http://www.ngksparkplugs.com/tech_support/spark_plugs/p2.asp?mode=nml 

 



I spent a little time reading the site and there is a lot of info there.

LUCKILY NGK plugs are not expensive so you can experiment.

 



Oh, BTW, what kind of probe are you using for CHT's, Gasket type under the spark plug?  They read HIGH and when used the plug gasket should not be used...  Now, sometimes the plug gasket cannot be removed.  What happens when two gaskets are used, the plug height changes and the spark location in the cylinder changes.  AND two gaskets do not transfer heat as well as as one gasket. This causes a plug to run HOTTER.  Use any other type of sensor that does not fit under the plug.  

 



Barry

On Fri, Apr 27, 2012 at 10:57 PM, ple190 <plge190(at)optusnet.com.au (plge190(at)optusnet.com.au)> wrote:

 [quote]--> JabiruEngine-List message posted by: "ple190" <plge190(at)optusnet.com.au (plge190(at)optusnet.com.au)>

  

 Thanks Nick and Barry

 Nick I have kit 104 with wheel fairing /pants installed and I'm running a 62FK58 prop

 The eng is   s/no 2246 so hyd lifter but not  the latest induction manifold

 Also I have a  way splitter in the air box outlet which did help and have also tried one in the smooth pipe thats on the carby intake and it didn't make any difference.

 My understanding of the Hackman is its a leaning device ? so not sure if this will help ?

 

 Barry do you have a part no for a hotter plug ? its worth a try

 



[b]

Lynn Matteson

Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan

Posted: Sat Apr 28, 2012 2:30 am Post subject: High EGT cyl 5 -running out of ideas

Peak EGT for any cylinder is the hottest that THAT cylinder reaches.  

With a normal Bing you have no way of setting the mixture on the fly,  

so the best you can do is to fly the plane while recording each and  

every cylinder's EGT, while at the same time recording your fuel  

flow. Like Old Bob said, if the cylinders all reach THEIR individual  

peaks at very nearly the same fuel flow, that's the best you can do.  

After all, you are dealing with a carbureted engine and a pretty  

poorly designed intake manifold, and that combination has proven to  

not be the best for trying to achieve EGT balance, whether it is the  

Jabiru engine or any/most of the other engines out there. That is why  

individual-port fuel injection was created.



I moved my EGT probe for my #1 cylinder (2200 Jabiru) 1", and did not  

see an appreciable change in EGT readings. Changing/swapping probes  

also did not change things.



Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062

Prince prop 64 x 30, P-tip

Electroair direct-fire ignition system

Rotec TBI-40 injection (sleeved to 36mm)

Status: flying with 1254 hrs... (since 3-27-2006)



On Apr 27, 2012, at 9:22 PM, ple190 wrote:



 	  Quote: 	
		   

 <plge190(at)optusnet.com.au>



 Thanks for the input guys.

 Old BOB ---The problem with the Jab and bing carb is no mixture  

 control so you have no way of knowing if your near peak EGT so I  

 dont know if No 5 if at/near or above peak EGT?



 Barry --All the probs are in the same spot from the port. No 5 was  

 a bit closer so i moved it to match the others with no change ?

 I will check if any cold air is being forced onto the senor

 Paul





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=371949#371949

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

barnett6088(at)msn.com
Guest

Posted: Sat Apr 28, 2012 3:04 pm Post subject: High EGT cyl 5 -running out of ideas

Paul

Just a little about a Hacman.  I have one in my lightning, SN 133, and I live at higher altitudes, field elevation 3250 ft, so I use it quite a bit when I am going somewhere cross country and above 8,000 ft.  It works well and my fuel burn at 10,500 averages about 5.4 gal/hour at 2850 RPM and 120 Knots.  It will allow you to check your peak EGT's but if you do check them do it above 9,000 ft to stay safely out of the detonation area.  This is a necessity on a carb. engine do to the wide variation in mixture between cylinders.  If the Jabiru were fuel injected and had GAMI injectors it would be much easier and simpler.  Be sure you enrich the mixture before you start down.  I forgot once (there is no mixture on the normal check list as it is an add on and it is mounted low on the center panel) the result was rather startling.  At reduced power while decending the engine continues to run smoothly until you close the throttle on downwind at say 70knots.  At that point the engine just stops cold with no fanfair at all and of course at 70-75 knots it will not windmill so the prop stops.  The Lightning has a great glide ratio so I didn't bother to restart it but I did get some strange looks from other pilots who saw me land and restart as I rolled onto the taxiway.  Gary  

 



 	  Quote: 	
		   Subject: Re: High EGT cyl 5 -running out of ideas

 From: plge190(at)optusnet.com.au

 Date: Fri, 27 Apr 2012 20:27:45 -0700

 To: jabiruengine-list(at)matronics.com

 

 --> JabiruEngine-List message posted by: "ple190" <plge190(at)optusnet.com.au>

 

 Nick- do you guys use the throttle extension on the carby ? I am and it limits the amount of twist you can get. 

 

 Also looking at the jets you are using Nick may I'm running too rich and as Barry said getting a burn in the exhaust pipe? I did increase the needle from 285 to 290 and it didn't help maybe even worse. I guess with the hackman I can lean out and see what happens. At least I'll know how close to peak I am.

  It runs well just don't want to do any damage !!

 

 checked all the plugs the other day and they are all quite black and No. 5 is the same as the others ?

 I miss the good old days of steam gauges--or lack there of

  "ignorance is bliss"

 Paul

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=371968#371968

 

 

 

 

 

 

 

&gt=========
	


 	  Quote: 	
		   

 

 


	


 		 	   		  

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