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BobbyPaulk(at)comcast.net Guest
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Posted: Wed Sep 04, 2013 4:30 pm Post subject: EGT |
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p { margin: 0; }
Guys
I am in the middle of my " Conditional" Inspection.
I put 37 hrs. on my 3300 since last year. I had 3/4" of clean honey colored oil in my catch bottle and used less than a quart for the 37 hrs.
I would like to cruise my Zodiac 601 at about 2700 RPM but the EGT gets over 1400 deg. on the back two cylinders and 1350 ~ 1375 on two others at that RPM range. I have to pull back the throttle to 2450 ~ 2500 RPM to get under 1350 EGT temps. If I raise the RPM to 2800 the EGT on #6 will decrease 50 to 60 degrees but #5 will go up about the same amount.
I am running a 260 main jet and a 285 needle jet. This is already much richer than the standard setup. I am thinking of drilling the needle jet out .001 and see if the EGT comes down a little. If so I might go another .001.
I am turning a 51" Sensenich prop in lieu of the standard 49" so it should take a little more fuel at a given RPM due to the MP being a little higher.
My plugs are showing a lean burning engine - light grey. I am using 93 Oct. non ethanol Marine gas and at 2400 ~ 2500 RPM burning less than 5 GPH.
Has anyone out there had to go this rich to get the EGT down under 1375. I have checked the float level and have a paper filter on the fuel line just before the carb. The float bowl is clean every time I have checked it.
Also I re-torqued my head bolts and over half took about 10 ~ 15 deg. before the torque wrench clicked. The ones that moved were all in the lower 3 of each cylinder.
Has anyone else had a similar experience or know of a fix??
Thanks,
Bobby ( age 75 )
Zodiac 601 XL "B"
Jabiru 3300 S/N 1141
Sensenich 64" x 51" Prop
Bing Carb 260 Main & 285 Needle Jet
Status - Flying 187 hrs.
Do Not Archive
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matronics(at)rtist.nl Guest
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Posted: Wed Sep 04, 2013 11:16 pm Post subject: EGT |
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I was running 255 main / 290 needle until recently, my EGT's were kinda on the high side. Then I placed the recently much-discussed 'X' (on Yahoo) in my carby inlet, hoping it would straiten the airflow.
It sure made a difference.. EGT's dropped to waaay too rich. I'm now on 250 main / 280 needle and EGT's are still richer than they were before. Perhaps it will do the same for you.
I'm attaching the drawing of my 'X' baffle, hope Matronics relays it. If not, you can find it in the Yahoo file section
Rob
On 9/5/2013 2:29 AM, BobbyPaulk(at)comcast.net (BobbyPaulk(at)comcast.net) wrote:
Quote: | p { margin: 0; } p { margin: 0; }
Guys
I am in the middle of my " Conditional" Inspection.
I put 37 hrs. on my 3300 since last year. I had 3/4" of clean honey colored oil in my catch bottle and used less than a quart for the 37 hrs.
I would like to cruise my Zodiac 601 at about 2700 RPM but the EGT gets over 1400 deg. on the back two cylinders and 1350 ~ 1375 on two others at that RPM range. I have to pull back the throttle to 2450 ~ 2500 RPM to get under 1350 EGT temps. If I raise the RPM to 2800 the EGT on #6 will decrease 50 to 60 degrees but #5 will go up about the same amount.
I am running a 260 main jet and a 285 needle jet. This is already much richer than the standard setup. I am thinking of drilling the needle jet out .001 and see if the EGT comes down a little. If so I might go another .001.
I am turning a 51" Sensenich prop in lieu of the standard 49" so it should take a little more fuel at a given RPM due to the MP being a little higher.
My plugs are showing a lean burning engine - light grey. I am using 93 Oct. non ethanol Marine gas and at 2400 ~ 2500 RPM burning less than 5 GPH.
Has anyone out there had to go this rich to get the EGT down under 1375. I have checked the float level and have a paper filter on the fuel line just before the carb. The float bowl is clean every time I have checked it.
Also I re-torqued my head bolts and over half took about 10 ~ 15 deg. before the torque wrench clicked. The ones that moved were all in the lower 3 of each cylinder.
Has anyone else had a similar experience or know of a fix??
Thanks,
Bobby ( age 75 )
Zodiac 601 XL "B"
Jabiru 3300 S/N 1141
Sensenich 64" x 51" Prop
Bing Carb 260 Main & 285 Needle Jet
Status - Flying 187 hrs.
Do Not Archive
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| - 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 |
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naftalih(at)hotmail.com Guest
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Posted: Thu Sep 05, 2013 12:26 am Post subject: EGT |
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Hi Rob,
How did you install the X?
Friction, adhesive?
Any fuel saving?
Kind regards,
Naftali.
Date: Thu, 5 Sep 2013 08:59:57 +0200
From: matronics(at)rtist.nl
To: jabiruengine-list(at)matronics.com
Subject: Re: EGT
I was running 255 main / 290 needle until recently, my EGT's were kinda on the high side. Then I placed the recently much-discussed 'X' (on Yahoo) in my carby inlet, hoping it would straiten the airflow.
It sure made a difference.. EGT's dropped to waaay too rich. I'm now on 250 main / 280 needle and EGT's are still richer than they were before. Perhaps it will do the same for you.
I'm attaching the drawing of my 'X' baffle, hope Matronics relays it. If not, you can find it in the Yahoo file section
Rob
On 9/5/2013 2:29 AM, BobbyPaulk(at)comcast.net (BobbyPaulk(at)comcast.net) wrote:
[quote]
Guys
I am in the middle of my " Conditional" Inspection.
I put 37 hrs. on my 3300 since last year. I had 3/4" of clean honey colored oil in my catch bottle and used less than a quart for the 37 hrs.
I would like to cruise my Zodiac 601 at about 2700 RPM but the EGT gets over 1400 deg. on the back two cylinders and 1350 ~ 1375 on two others at that RPM range. I have to pull back the throttle to 2450 ~ 2500 RPM to get under 1350 EGT temps. If I raise the RPM to 2800 the EGT on #6 will decrease 50 to 60 degrees but #5 will go up about the same amount.
I am running a 260 main jet and a 285 needle jet. This is already much richer than the standard setup. I am thinking of drilling the needle jet out .001 and see if the EGT comes down a little. If so I might go another .001.
I am turning a 51" Sensenich prop in lieu of the standard 49" so it should take a little more fuel at a given RPM due to the MP being a little higher.
My plugs are showing a lean burning engine - light grey. I am using 93 Oct. non ethanol Marine gas and at 2400 ~ 2500 RPM burning less than 5 GPH.
Has anyone out there had to go this rich to get the EGT down under 1375. I have checked the float level and have a paper filter on the fuel line just before the carb. The float bowl is clean every time I have checked it.
Also I re-torqued my head bolts and over half took about 10 ~ 15 deg. before the torque wrench clicked. The ones that moved were all in the lower 3 of each cylinder.
Has anyone else had a similar experience or know of a fix??
Thanks,
Bobby ( age 75 )
Zodiac 601 XL "B"
Jabiru 3300 S/N 1141
Sensenich 64" x 51" Prop
Bing Carb 260 Main & 285 Needle Jet
Status - Flying 187 hrs.
Do Not Archive
[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 |
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matronics(at)rtist.nl Guest
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Posted: Thu Sep 05, 2013 2:29 am Post subject: EGT |
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Hi Naftali,
I made the X out of thin brass sheet. Two slits make it fit together, then I soldered it through. The shape width is such that the top of the 'mushroom' sits on the rim of the carb. In addition I soldered small tabs on the outside of the mushroom (not on my drawing) which clamp on the outside of the carb rim. The SCAT tube slides over these tabs and the clamp keeps everything neatly in place.
Too early to tell if I have significant fuel savings. The engine behaves different, using 18l/hr at 2500rpm, but going up to 25l/hr as soon as I pass 2700rpm. It used to be 19-21 l/hr anywhere between 2500 and 2700rpm. I still need to find the ideal needle/jet combination for this new situation.
Rob
On 9/5/2013 10:25 AM, Naftali Horowitz wrote:
[quote] Hi Rob,
How did you install the X?
Friction, adhesive?
Any fuel saving?
Kind regards,
Naftali.
Date: Thu, 5 Sep 2013 08:59:57 +0200
From: matronics(at)rtist.nl (matronics(at)rtist.nl)
To: jabiruengine-list(at)matronics.com (jabiruengine-list(at)matronics.com)
Subject: Re: EGT
I was running 255 main / 290 needle until recently, my EGT's were kinda on the high side. Then I placed the recently much-discussed 'X' (on Yahoo) in my carby inlet, hoping it would straiten the airflow.
It sure made a difference.. EGT's dropped to waaay too rich. I'm now on 250 main / 280 needle and EGT's are still richer than they were before. Perhaps it will do the same for you.
I'm attaching the drawing of my 'X' baffle, hope Matronics relays it. If not, you can find it in the Yahoo file section
Rob
On 9/5/2013 2:29 AM, BobbyPaulk(at)comcast.net (BobbyPaulk(at)comcast.net) wrote:
Quote: |
Guys
I am in the middle of my " Conditional" Inspection.
I put 37 hrs. on my 3300 since last year. I had 3/4" of clean honey colored oil in my catch bottle and used less than a quart for the 37 hrs.
I would like to cruise my Zodiac 601 at about 2700 RPM but the EGT gets over 1400 deg. on the back two cylinders and 1350 ~ 1375 on two others at that RPM range. I have to pull back the throttle to 2450 ~ 2500 RPM to get under 1350 EGT temps. If I raise the RPM to 2800 the EGT on #6 will decrease 50 to 60 degrees but #5 will go up about the same amount.
I am running a 260 main jet and a 285 needle jet. This is already much richer than the standard setup. I am thinking of drilling the needle jet out .001 and see if the EGT comes down a little. If so I might go another .001.
I am turning a 51" Sensenich prop in lieu of the standard 49" so it should take a little more fuel at a given RPM due to the MP being a little higher.
My plugs are showing a lean burning engine - light grey. I am using 93 Oct. non ethanol Marine gas and at 2400 ~ 2500 RPM burning less than 5 GPH.
Has anyone out there had to go this rich to get the EGT down under 1375. I have checked the float level and have a paper filter on the fuel line just before the carb. The float bowl is clean every time I have checked it.
Also I re-torqued my head bolts and over half took about 10 ~ 15 deg. before the torque wrench clicked. The ones that moved were all in the lower 3 of each cylinder.
Has anyone else had a similar experience or know of a fix??
Thanks,
Bobby ( age 75 )
Zodiac 601 XL "B"
Jabiru 3300 S/N 1141
Sensenich 64" x 51" Prop
Bing Carb 260 Main & 285 Needle Jet
Status - Flying 187 hrs.
Do Not Archive
| [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 |
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Back to top |
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naftalih(at)hotmail.com Guest
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Posted: Thu Sep 05, 2013 8:17 am Post subject: EGT |
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Thanks Rob
Date: Thu, 5 Sep 2013 12:27:59 +0200
From: matronics(at)rtist.nl
To: jabiruengine-list(at)matronics.com
Subject: Re: JabiruEngine-List: EGT
Hi Naftali,
I made the X out of thin brass sheet. Two slits make it fit together, then I soldered it through. The shape width is such that the top of the 'mushroom' sits on the rim of the carb. In addition I soldered small tabs on the outside of the mushroom (not on my drawing) which clamp on the outside of the carb rim. The SCAT tube slides over these tabs and the clamp keeps everything neatly in place.
Too early to tell if I have significant fuel savings. The engine behaves different, using 18l/hr at 2500rpm, but going up to 25l/hr as soon as I pass 2700rpm. It used to be 19-21 l/hr anywhere between 2500 and 2700rpm. I still need to find the ideal needle/jet combination for this new situation.
Rob
On 9/5/2013 10:25 AM, Naftali Horowitz wrote:
[quote] Hi Rob,
How did you install the X?
Friction, adhesive?
Any fuel saving?
Kind regards,
Naftali.
Date: Thu, 5 Sep 2013 08:59:57 +0200
From: matronics(at)rtist.nl (matronics(at)rtist.nl)
To: jabiruengine-list(at)matronics.com (jabiruengine-list(at)matronics.com)
Subject: Re: EGT
I was running 255 main / 290 needle until recently, my EGT's were kinda on the high side. Then I placed the recently much-discussed 'X' (on Yahoo) in my carby inlet, hoping it would straiten the airflow.
It sure made a difference.. EGT's dropped to waaay too rich. I'm now on 250 main / 280 needle and EGT's are still richer than they were before. Perhaps it will do the same for you.
I'm attaching the drawing of my 'X' baffle, hope Matronics relays it. If not, you can find it in the Yahoo file section
Rob
On 9/5/2013 2:29 AM, BobbyPaulk(at)comcast.net (BobbyPaulk(at)comcast.net) wrote:
Quote: |
Guys
I am in the middle of my " Conditional" Inspection.
I put 37 hrs. on my 3300 since last year. I had 3/4" of clean honey colored oil in my catch bottle and used less than a quart for the 37 hrs.
I would like to cruise my Zodiac 601 at about 2700 RPM but the EGT gets over 1400 deg. on the back two cylinders and 1350 ~ 1375 on two others at that RPM range. I have to pull back the throttle to 2450 ~ 2500 RPM to get under 1350 EGT temps. If I raise the RPM to 2800 the EGT on #6 will decrease 50 to 60 degrees but #5 will go up about the same amount.
I am running a 260 main jet and a 285 needle jet. This is already much richer than the standard setup. I am thinking of drilling the needle jet out .001 and see if the EGT comes down a little. If so I might go another .001.
I am turning a 51" Sensenich prop in lieu of the standard 49" so it should take a little more fuel at a given RPM due to the MP being a little higher.
My plugs are showing a lean burning engine - light grey. I am using 93 Oct. non ethanol Marine gas and at 2400 ~ 2500 RPM burning less than 5 GPH.
Has anyone out there had to go this rich to get the EGT down under 1375. I have checked the float level and have a paper filter on the fuel line just before the carb. The float bowl is clean every time I have checked it.
Also I re-torqued my head bolts and over half took about 10 ~ 15 deg. before the torque wrench clicked. The ones that moved were all in the lower 3 of each cylinder.
Has anyone else had a similar experience or know of a fix??
Thanks,
Bobby ( age 75 )
Zodiac 601 XL "B"
Jabiru 3300 S/N 1141
Sensenich 64" x 51" Prop
Bing Carb 260 Main & 285 Needle Jet
Status - Flying 187 hrs.
Do Not Archive
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