Matronics Email Lists :: View topic - Jabiru 3300 cooling and noise

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

Jabiru 3300 cooling and noise

Matronics Email Lists Forum Index -> Zenith601-List

View previous topic :: View next topic

Author Message

mhubel

Joined: 05 Sep 2009
Posts: 141

Posted: Mon Jul 11, 2011 2:04 pm Post subject: Jabiru 3300 cooling and noise

I wonder how others have faired with the Jabiru 3300 in the 601XL airframe. 



I find that even doing everything right, - oil at bottom of dipstick range, 4-5 inches of H2O pressure across the oil cooler and the same on the cylinder heads I have oil temps of 220F with a OAT of 65F at 4500 FT and 6.5 GPH (which is probably about 70% power). Any attempt to run the power even slightly higher results in 230+ temps. At lower altitudes where the OAT is higher, the problem is worse.



Then there is the ignition. I have put in Magnacore suppression wire on the magnetos. The wire to the plugs seems to be a high quality suppression wire. There are ferrite cores on every wire. While it is much better than the "as supplied by Jabiru" level, it is still not acceptable for hearing ATC at the edges of their normal hand off range. 



I have isolated the radio and tried running it on its own battery (no effect). Disconnecting the antenna wire eliminates all noise so it is all coming in through the antenna. I have removed the P leads on the mags  and verified they have no effect. All the noise seems to be coming through the high voltage side.

_________________
Mark Hubelbank
N708HU
CH601XL
Jabiru 3300
Rotec TBI 40-3 carb
Sensenich ground adj prop.
240 hr TAF
Pictures at photo.hubbles.com

psm(at)att.net
Guest

Posted: Mon Jul 11, 2011 3:21 pm Post subject: Jabiru 3300 cooling and noise

Hi Mark,



I wonder how big the ground wire is between your engine and central 

ground point.  Mine is a piece of copper braid that is about 1 inch 

across folded (it is actually a tube lying flat).  That is a lot of 

copper.  I have a smaller piece of copper braid going from the central 

ground point, on my firewall, to the metal instrument panel.



I can't give you a good explanation of why I did this, but a couple of 

decades designing digital electronics for production taught me you just 

can't have too much ground current capacity.



You can get copper braid wire (it looks like silver because of solder 

dipping) at any amateur radio supplier.



I don't have much experience yet with this plane but the radio seems to 

work just fine.



One other nasty possibility is that there just isn't a good shield in 

your radio.  This is not easy to fix.  (Mine is a Garmin SL-30.)



Paul

XL just entered flight test.



On 7/11/2011 3:04 PM, mhubel wrote:

 	  Quote: 	
		   



 I wonder how others have faired with the Jabiru 3300 in the 601XL airframe.



 I find that even doing everything right, - oil at bottom of dipstick range, 4-5 inches of H2O pressure across the oil cooler and the same on the cylinder heads I have oil temps of 220F with a OAT of 65F at 4500 FT and 6.5 GPH (which is probably about 70% power). Any attempt to run the power even slightly higher results in 230+ temps. At lower altitudes where the OAT is higher, the problem is worse.



 Then there is the ignition. I have put in Magnacore suppression wire on the magnetos. The wire to the plugs seems to be a high quality suppression wire. There are ferrite cores on every wire. While it is much better than the "as supplied by Jabiru" level, it is still not acceptable for hearing ATC at the edges of their normal hand off range.



 I have isolated the radio and tried running it on its own battery (no effect). Disconnecting the antenna wire eliminates all noise so it is all coming in through the antenna. I have removed the P leads on the mags  and verified they have no effect. All the noise seems to be coming through the high voltage side.



 --------

 Mark Hubelbank

 N708HU

 CH601XL

 Jabiru 3300

 Rotec TBI 40-3 carb

 Sensenich ground adj prop.

 70 hr TAF

 Pictures at photo.hubbles.com





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=345960#345960

mhubel

Joined: 05 Sep 2009
Posts: 141

Posted: Mon Jul 11, 2011 4:52 pm Post subject: Jabiru 3300 cooling and noise

Paul,

     The ground is a short run of #4 wire. I also had the thought that 

the ground might be making it worse. The only thing that your 

installation might point out is that you have a SL-30. I suspect that 

Garmin had a noise spike suppressor in the design. It is unlikely that 

the radio I have has that. A really good spike suppression circuit can 

reduce the noise 20 db or so. I think I will try an experiment with a 

King handheld that I have access to. Even if that works, it does not 

eliminate the source of the noise, it just masks it.

On 07/11/2011 7:18 PM, Paul Mulwitz wrote:

 	  Quote: 	

 Hi Mark,

 I wonder how big the ground wire is between your engine and central 

 ground point.  Mine is a piece of copper braid that is about 1 inch 

 across folded (it is actually a tube lying flat).  That is a lot of 

 copper.  I have a smaller piece of copper braid going from the central 

 ground point, on my firewall, to the metal instrument panel.

 I can't give you a good explanation of why I did this, but a couple of 

 decades designing digital electronics for production taught me you 

 just can't have too much ground current capacity.

 You can get copper braid wire (it looks like silver because of solder 

 dipping) at any amateur radio supplier.

 I don't have much experience yet with this plane but the radio seems 

 to work just fine.

 One other nasty possibility is that there just isn't a good shield in 

 your radio.  This is not easy to fix.  (Mine is a Garmin SL-30.)

 Paul

 XL just entered flight test.

 On 7/11/2011 3:04 PM, mhubel wrote:

> 

>

> I wonder how others have faired with the Jabiru 3300 in the 601XL 

> airframe.

>

> I find that even doing everything right, - oil at bottom of dipstick 

> range, 4-5 inches of H2O pressure across the oil cooler and the same 

> on the cylinder heads I have oil temps of 220F with a OAT of 65F at 

> 4500 FT and 6.5 GPH (which is probably about 70% power). Any attempt 

> to run the power even slightly higher results in 230+ temps. At lower 

> altitudes where the OAT is higher, the problem is worse.

>

> Then there is the ignition. I have put in Magnacore suppression wire 

> on the magnetos. The wire to the plugs seems to be a high quality 

> suppression wire. There are ferrite cores on every wire. While it is 

> much better than the "as supplied by Jabiru" level, it is still not 

> acceptable for hearing ATC at the edges of their normal hand off range.

>

> I have isolated the radio and tried running it on its own battery (no 

> effect). Disconnecting the antenna wire eliminates all noise so it is 

> all coming in through the antenna. I have removed the P leads on the 

> mags  and verified they have no effect. All the noise seems to be 

> coming through the high voltage side.

>

> --------

> Mark Hubelbank

> N708HU

> CH601XL

> Jabiru 3300

> Rotec TBI 40-3 carb

> Sensenich ground adj prop.

> 70 hr TAF

> Pictures at photo.hubbles.com

>

>

> Read this topic online here:

>

> http://forums.matronics.com/viewtopic.php?p=345960#345960

-- 

Mark Hubelbank

NorthEast Monitoring

2 Clock Tower Place

Suite 555

Maynard, MA, 01754 - USA

mhubel(at)nemon.com

978-443-3955

_________________
Mark Hubelbank
N708HU
CH601XL
Jabiru 3300
Rotec TBI 40-3 carb
Sensenich ground adj prop.
240 hr TAF
Pictures at photo.hubbles.com

psm(at)att.net
Guest

Posted: Mon Jul 11, 2011 5:22 pm Post subject: Jabiru 3300 cooling and noise

Hi Mark,



I think a 1 inch wide copper braid would produce a lot better ground - 

particularly for RF noise - than a #4 round wire cable.  The copper in 

your wire would provide plenty of DC current capacity for the starter 

motor, but RF noise might jump right around it.



There is a phenomenon called "Skin effect" that makes high frequency 

signals migrate away from the center of a conductor.  The higher the 

frequency the more it stays away from the center.  For very high 

frequency noise - around the 120 MHz used by your comm radio this would 

make your round wire look like a thin tube.



You can test my idea relatively easily with a big automotive jumper 

cable attached between the engine and ground point on  your firewall.  

If this makes the noise change at all it will give a clue to the real 

problem you are experiencing.  You can coil up the jumper cable and add 

a few tie-wraps to keep it out of the way.



Ground problems have always been the hardest ones for me to find (along 

with all my colleagues).  Of course this presumes you are not dealing 

with a software problem.  Those accounted for about 99 percent of all my 

field problems.



Paul



On 7/11/2011 5:50 PM, Mark Hubelbank wrote:

 	  Quote: 	
		   



 Paul,

     The ground is a short run of #4 wire. I also had the thought that 

 the ground might be making it worse. The only thing that your 

 installation might point out is that you have a SL-30. I suspect that 

 Garmin had a noise spike suppressor in the design. It is unlikely that 

 the radio I have has that. A really good spike suppression circuit can 

 reduce the noise 20 db or so. I think I will try an experiment with a 

 King handheld that I have access to. Even if that works, it does not 

 eliminate the source of the noise, it just masks it.



 On 07/11/2011 7:18 PM, Paul Mulwitz wrote:

> 

>

> Hi Mark,

>

> I wonder how big the ground wire is between your engine and central 

> ground point.  Mine is a piece of copper braid that is about 1 inch 

> across folded (it is actually a tube lying flat).  That is a lot of 

> copper.  I have a smaller piece of copper braid going from the 

> central ground point, on my firewall, to the metal instrument panel.

>

> I can't give you a good explanation of why I did this, but a couple 

> of decades designing digital electronics for production taught me you 

> just can't have too much ground current capacity.

>

> You can get copper braid wire (it looks like silver because of solder 

> dipping) at any amateur radio supplier.

>

> I don't have much experience yet with this plane but the radio seems 

> to work just fine.

>

> One other nasty possibility is that there just isn't a good shield in 

> your radio.  This is not easy to fix.  (Mine is a Garmin SL-30.)

>

> Paul

> XL just entered flight test.

>

> On 7/11/2011 3:04 PM, mhubel wrote:

>> 

>>

>> I wonder how others have faired with the Jabiru 3300 in the 601XL 

>> airframe.

>>

>> I find that even doing everything right, - oil at bottom of dipstick 

>> range, 4-5 inches of H2O pressure across the oil cooler and the same 

>> on the cylinder heads I have oil temps of 220F with a OAT of 65F at 

>> 4500 FT and 6.5 GPH (which is probably about 70% power). Any attempt 

>> to run the power even slightly higher results in 230+ temps. At 

>> lower altitudes where the OAT is higher, the problem is worse.

>>

>> Then there is the ignition. I have put in Magnacore suppression wire 

>> on the magnetos. The wire to the plugs seems to be a high quality 

>> suppression wire. There are ferrite cores on every wire. While it is 

>> much better than the "as supplied by Jabiru" level, it is still not 

>> acceptable for hearing ATC at the edges of their normal hand off range.

>>

>> I have isolated the radio and tried running it on its own battery 

>> (no effect). Disconnecting the antenna wire eliminates all noise so 

>> it is all coming in through the antenna. I have removed the P leads 

>> on the mags  and verified they have no effect. All the noise seems 

>> to be coming through the high voltage side.

>>

>> --------

>> Mark Hubelbank

>> N708HU

>> CH601XL

>> Jabiru 3300

>> Rotec TBI 40-3 carb

>> Sensenich ground adj prop.

>> 70 hr TAF

>> Pictures at photo.hubbles.com

>>

>>

>>

>>

>> Read this topic online here:

>>

>> http://forums.matronics.com/viewtopic.php?p=345960#345960

>>

>>

>>

>>

>>

>>

>

jeffrey_davidson(at)earth
Guest

Posted: Mon Jul 11, 2011 5:32 pm Post subject: Jabiru 3300 cooling and noise

Mark,

For the high oil temperatures, you might look at the air intake in the cowling for the oil cooler.  For mine, I fashioned an air plenum to force the air into the oil cooler.  I used Aluminum on the sides of the opening in the Jabiru cowling and a thick piece of rubber baffling riveted to an L that is attached to the rear two oil cooler attachments.  The end result is that air can't go past the cooler either under it or around to the side.  Just a suggestion.

Jeff Davidson 

--

DaveG601XL

Joined: 27 Oct 2006
Posts: 351
Location: Cincinnati, Oh

Posted: Tue Jul 12, 2011 3:30 am Post subject: Re: Jabiru 3300 cooling and noise

Mark,



I am also using a #4 round cable for engine grounding.  I have an I-com A200 radio, which is certainly not a high-end model that I doubt has anything for spike suppression built-in.  I have no engine-induced radio noise and have been told my transmissions are pretty clear.  I get a little strobe noise in the system, but that is about it.  Have you tried a new antenna or antenna wire?  Antenna installation and grounding to the aircraft skin itself is quite important too.  Also, have you taken your issue to the AeroElectric forum here in Matronics??  There are some real voltheads over there.



Do you have the early style, flat, automotive oil cooler or the newer Positech cooler.  I have the Positech installed per the Jabiru instructions and have no real issues with it.  Oil temps up to 90F oat are usually below 220F.  202-212F are more typical for an average summer flying day.  I did add some additional aluminum and RTV around the cooler to ensure as much air as possible goes through it, but that is about it.

_________________
David Gallagher
Cincinnati, OH area

mhubel

Joined: 05 Sep 2009
Posts: 141

Posted: Tue Jul 12, 2011 4:58 am Post subject: Jabiru 3300 cooling and noise

David,

     I am almost sure the ICOM line all have some form of ANL (automatic 

noise limiting) in the design I will see if I can check that out. It is 

really very simple. Unfourtunately, the Microair M760 I have clearly 

does not. This week, I am going to do some tests with signal processing 

to simulate an ANL. If that works, I will probably build one as an add 

on. The alternative would be to use a Becker radio and I have heard 

mixed reports on the noise rejection of a Becker it may not have ANL 

either. If my test works, I will publish the design.



     I have proved that all the noise comes in through the antenna lead. 

The antenna is on the bottom of the fuselage behind the seats, any 

further back and there would be risk of antenna contact during landing. 

Still one source of noise is the exhaust pipe which can act as an 

antenna. I have not been able to do a test to eliminate that yet. Where 

is your antenna?



     I have the Positech cooler with oversize hose and it is very well 

sealed on the air intake side. There is a lot of air moving through it. 

I am wondering if this engine has one of the rubbing piston cylinders 

and is generating excess heat. It does not show when turning it over by 

hand but when the engine is very hot, perhaps the clearances are too 

small. If that is the issue, I don't think it is being changed.

     Note that I can also keep oil temps down to under 220F (which is 

still above Jabiru recommendations) if I keep the power down to under 

6GPH which is well under 75% given the inefficiency of these engines. 

When I actually want to go somewhere and use a "high cruse" of 2900-3000 

RPM at 4500 to 5500 feet and 7 GPH, the oil temperature climbs sharply.



On 07/12/2011 7:30 AM, DaveG601XL wrote:

 	  Quote: 	
		   



 Mark,



 I am also using a #4 round cable for engine grounding.  I have an I-com A200 radio, which is certainly not a high-end model that I doubt has anything for spike suppression built-in.  I have no engine-induced radio noise and have been told my transmissions are pretty clear.  I get a little strobe noise in the system, but that is about it.  Have you tried a new antenna or antenna wire?  Antenna installation and grounding to the aircraft skin itself is quite important too.  Also, have you taken your issue to the AeroElectric forum here in Matronics??  There are some real voltheads over there.



 Do you have the early style, flat, automotive oil cooler or the newer Positech cooler.  I have the Positech installed per the Jabiru instructions and have no real issues with it.  Oil temps up to 90F oat are usually below 220F.  202-212F are more typical for an average summer flying day.  I did add some additional aluminum and RTV around the cooler to ensure as much air as possible goes through it, but that is about it.



 --------

 David Gallagher

 601 XL/Jabiru 3300

 First flight 7/24/08, Upgraded 3/19/10

 Flew it to Oshkosh '09&amp; '10

 180+ hours and climbing!





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=346034#346034




	


-- 

Mark Hubelbank

NorthEast Monitoring

2 Clock Tower Place

Suite 555

Maynard, MA, 01754 - USA

mhubel(at)nemon.com

978-443-3955

_________________
Mark Hubelbank
N708HU
CH601XL
Jabiru 3300
Rotec TBI 40-3 carb
Sensenich ground adj prop.
240 hr TAF
Pictures at photo.hubbles.com

DaveG601XL

Joined: 27 Oct 2006
Posts: 351
Location: Cincinnati, Oh

Posted: Tue Jul 12, 2011 6:37 am Post subject: Re: Jabiru 3300 cooling and noise

Mark,



You are certainly more well versed in radio technology than I am so I will check out of that discussion and monitor it from aside.  My antenna is mounted on top near the rear of the baggage deck.  I have had people ask me if I tuned my antenna or cable lengths with a SWR meter and all I can do is give a dumb stare in return.  I just hooked them all up and started talking.



Have you tried extending the rear cowl lip to see if the added pressure drop helps??  Since you already know the pressure drop across your cooler, I assume you are well versed in that trick also.  I have the Sensenich wood prop that I am told is shaped to help with hub airflow.



How about a new oil temp thermocouple?  They are "usually" pretty bullet proof but that would at least eliminate the instrumentation as a source of your problem.  Dropping it in boiling water and watching the Dynon readout would would serve the same purpose.  Hopefully there are no junctions in the thermocouple wire between the thermocouple and your Dynon.



Just to compare observations, it looks like you cruise around faster than I do.  If I am just tooling around the area, I set ~2650 RPM.  Solo, this gets me about 115MPH IAS and the 100LL flows at around 4.5 GPH.  If I kick it up to 2850 RPM, it only seems to get me another 10 MPH at 6.5 GPH.  I usually keep the throttle between 2650 and 2750 RPM for cross countries.  With my wood prop, I only see 3000 RPM if I am WOT and in a slight dive.



Good luck,

_________________
David Gallagher
Cincinnati, OH area

mhubel

Joined: 05 Sep 2009
Posts: 141

Posted: Tue Jul 12, 2011 7:25 am Post subject: Jabiru 3300 cooling and noise

David,

     I did the sensor calibration and also did tests with thermocouples 

on both sides of the oil cooler. Even though the pressure difference is 

well within spec, I may still try the bigger lip just for the summer. If 

that helps, then one does ask why.



     If my theory that the exhaust system can act as an antenna (leaking 

RF from the cylinders). then your top mounted antenna would be better 

even if in theory it is not as good for ATC communications. I had a AA-5 

with an antenna on the top and one on the bottom and the bottom mounted 

one was clearly better for some ATC use, that is why I picked the bottom 

location. Still I can think of a way I can do a test to try it without 

actually making a hole and mounting an antenna.



On 07/12/2011 10:37 AM, DaveG601XL wrote:

 	  Quote: 	
		   



 Mark,



 You are certainly more well versed in radio technology than I am so I will check out of that discussion and monitor it from aside.  My antenna is mounted on top near the rear of the baggage deck.  I have had people ask me if I tuned my antenna or cable lengths with a SWR meter and all I can do is give a dumb stare in return.  I just hooked them all up and started talking.



 Have you tried extending the rear cowl lip to see if the added pressure drop helps??  Since you already know the pressure drop across your cooler, I assume you are well versed in that trick also.  I have the Sensenich wood prop that I am told is shaped to help with hub airflow.



 How about a new oil temp thermocouple?  They are "usually" pretty bullet proof but that would at least eliminate the instrumentation as a source of your problem.  Dropping it in boiling water and watching the Dynon readout would would serve the same purpose.  Hopefully there are no junctions in the thermocouple wire between the thermocouple and your Dynon.



 Just to compare observations, it looks like you cruise around faster than I do.  If I am just tooling around the area, I set ~2650 RPM.  Solo, this gets me about 115MPH IAS and the 100LL flows at around 4.5 GPH.  If I kick it up to 2850 RPM, it only seems to get me another 10 MPH at 6.5 GPH.  I usually keep the throttle between 2650 and 2750 RPM for cross countries.  With my wood prop, I only see 3000 RPM if I am WOT and in a slight dive.



 Good luck,



 --------

 David Gallagher

 601 XL/Jabiru 3300

 First flight 7/24/08, Upgraded 3/19/10

 Flew it to Oshkosh '09&amp; '10

 180+ hours and climbing!





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=346059#346059




	


-- 

Mark Hubelbank

NorthEast Monitoring

2 Clock Tower Place

Suite 555

Maynard, MA, 01754 - USA

mhubel(at)nemon.com

978-443-3955

_________________
Mark Hubelbank
N708HU
CH601XL
Jabiru 3300
Rotec TBI 40-3 carb
Sensenich ground adj prop.
240 hr TAF
Pictures at photo.hubbles.com

psm(at)att.net
Guest

Posted: Tue Jul 12, 2011 7:50 am Post subject: Jabiru 3300 cooling and noise

Mark,



If you think RF from the engine is being radiated from the exhaust 

system then the way to fix this is to improve the grounding of the 

engine.  If the engine is well grounded it cannot radiate any signals.



Paul



On 7/12/2011 8:22 AM, Mark Hubelbank wrote:

 	  Quote: 	
		   David,

     I did the sensor calibration and also did tests with thermocouples 

 on both sides of the oil cooler. Even though the pressure difference 

 is well within spec, I may still try the bigger lip just for the 

 summer. If that helps, then one does ask why.



     If my theory that the exhaust system can act as an antenna 

 (leaking RF from the cylinders). then your top mounted antenna would 

 be better even if in theory it is not as good for ATC communications. 

 I had a AA-5 with an antenna on the top and one on the bottom and the 

 bottom mounted one was clearly better for some ATC use, that is why I 

 picked the bottom location. Still I can think of a way I can do a test 

 to try it without actually making a hole and mounting an antenna.

mhubel

Joined: 05 Sep 2009
Posts: 141

Posted: Tue Jul 12, 2011 8:16 am Post subject: Jabiru 3300 cooling and noise

Paul,

     Unfourtunately that is not completely true. The length of the 

exhaust pipe from the muffler is almost an ideal 1/4 wavelength antenna 

at aircraft VHF frequencies. Even if everything is perfectly grounded, 

if some RF energy is coupled from the cylinders or adjacent spark plug 

wires into the exhaust system, it will do an excellent job of radiating. 

Some tests will tell, not easy but it can be done. If this is really 

happening, it might explain why some people have success with resistor 

plugs. We might note that most production aircraft spark plugs are 

resistor designs even with shielded wires. This is all theory.



On 07/12/2011 11:46 AM, Paul Mulwitz wrote:

 	  Quote: 	
		   



 Mark,



 If you think RF from the engine is being radiated from the exhaust 

 system then the way to fix this is to improve the grounding of the 

 engine.  If the engine is well grounded it cannot radiate any signals.



 Paul



 On 7/12/2011 8:22 AM, Mark Hubelbank wrote:

> David,

>     I did the sensor calibration and also did tests with 

> thermocouples on both sides of the oil cooler. Even though the 

> pressure difference is well within spec, I may still try the bigger 

> lip just for the summer. If that helps, then one does ask why.

>

>     If my theory that the exhaust system can act as an antenna 

> (leaking RF from the cylinders). then your top mounted antenna would 

> be better even if in theory it is not as good for ATC communications. 

> I had a AA-5 with an antenna on the top and one on the bottom and the 

> bottom mounted one was clearly better for some ATC use, that is why I 

> picked the bottom location. Still I can think of a way I can do a 

> test to try it without actually making a hole and mounting an antenna.




	


-- 

Mark Hubelbank

NorthEast Monitoring

2 Clock Tower Place

Suite 555

Maynard, MA, 01754 - USA

mhubel(at)nemon.com

978-443-3955

_________________
Mark Hubelbank
N708HU
CH601XL
Jabiru 3300
Rotec TBI 40-3 carb
Sensenich ground adj prop.
240 hr TAF
Pictures at photo.hubbles.com

Display posts from previous:

	Matronics Email Lists Forum Index -> Zenith601-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